Jupiter a place of colossal storms
deadly radiation and captivating Beauty
a Powerhouse whose mass is so great it
influences even the sun
itself Jupiter is fast becoming one of
the most studied objects in our solar
system with seven flybys two orbiters
with one still in operation today and
two additional planned missions there is
so much to know about the fifth planet
from the Sun what causes its distinctive
red coloration what is it made of What
Lies Beneath its obscuring clouds what
do we know about its Great Red Spot
Jupiter holds a vital role in protecting
our solar system and it's time to delve
into its
Mysteries I'm Alex molan and welcome to
astram join me today as we explain every you could want to know about
Jupiter the fifth planet from the sun
Jupiter is found on the outskirts of the
asteroid belt and sits between the
orbits of Mars and Saturn it is
778 million km away from the sun on
average or 5.2 astronomical units and
completes an orbit every 12 earth years
the axile tilt of the planet is small
only 3°
this means it doesn't experience much
change in Seasons unlike Earth and Mars
and very much like Saturn its radius at
the equator is greater than at the poles
it is a massive Planet the largest in
our solar system it is so massive its
mass is a thousandth that of our sun
that might not seem like a lot but once
you realize the sun contains
99.86% of all all the mass in the solar
system you'll realize that Jupiter
equals almost the remainder its mass is
2 and a half times that of all the other
planets in the solar system combined and
this brings about an interesting
phenomenon the Barry Center between
Jupiter and the sun is actually above
the surface of the Sun at
1.68 solar radi from the Sun Center
let's talk about bar centers when we
think think of an object orbiting
another object we don't necessarily
think that the smaller object has a
gravitational influence on the bigger
object that's because most of the time
the effect is negligible like the ISS
orbiting Earth or even Mercury orbiting
the Sun but it does still happen a baric
center is the center of mass between
these two orbiting objects or the
location in space they both orbit around
with Jupiter being the mass and distance
from the Sun it is unlike Mercury its
effect is far from
negligible as Jupiter swings around the
Sun both of them do a little dance
around this Center of mass which is
actually above the surface of the Sun
let me show you this principle with an
example if I get a heavy object and a
less heavy object and attach them to the
ends of a long stick in order for the
stick to balance we need to find the
center of
mass as you can see the center of mass
is closer to the heavier object imagine
this is the Sun and Jupiter with the
stick being gravity and you'll
understand how a bar Center
Works while Jupiter has the greatest
mass of any planet in the solar system
it's not the densest it is the most
massive because it is the largest if
Neptune was the same size as Jupiter it
would be the most massive massive and if
Jupiter was the same size as Earth Earth
would be over four times more massive as
it is though the diameter of Jupiter is
11 times that of earth and its total
mass is
318 times more than Earth's as we know
Mass affects gravity this means that
Jupiter has a huge gravity over twice
that of Earth at
2528 G at its surface the gravity of
Jupiter is so influential in the solar
system that it affects every planet to
one degree or another its gravity is
strong enough to tear asteroids apart
and capture 67 moons at
least some scientists think that Jupiter
destroyed many celestial objects in the
ancient past as well as preventing other
planets from forming one example of this
in particular is for
Vester scientists even predict the
gravity of Jupiter is so significant
around the solar system that it is
perturbing Mercury's already eccentric
orbit enough that in a few billion years
the tiny planets May either crash into
the Sun or be ejected from the solar
system all together at the moment though
it could be the hero of the four inner
planets without Jupiter acting as a
cosmic vacuum cleaner it wouldn't be
sucking up dangerous objects like long
period comets or perturbing their orbits
enough to give them a little kick of
energy so that they leave the solar
system all
together Jupiter is the fifth planet
from the sun and it's five times further
away from the Sun than Earth even so it
can be the third brightest object in the
night sky after the moon and Venus I
just want to show you how bright that is
just using a handicam we can see Jupiter
quite easily in the night sky with a
maximum magnitude of -
2.94 it can actually cast
shadows as a result of it being so
obvious in the sky it makes a very nice
Target for amateur astronomers as
consumer telescopes have improved in
recent years it's amazing what details
you can see from your back garden and
what makes these famous patterns the
cloud layer is only about 50 km thick
and contains ammonia crystals much like
on Saturn but the coloration comes from
compounds heating up from deep within
Jupiter and then Rising these compounds
are known as chromophor and when they
reach the clouds they interact with the
UV light of the sun to create these
spectacular multicolored bands this is
quite the cycle though and the face of
Jupiter can change dramatically over
time even if their colors do change the
actual latitude of these bands remains
consistent enough to be given
identifying designations but they can
vary in width over the course of time
lots of Storms and turbulence occur
where these bands meet and it is the
reason and engine behind Jupiter's very
famous Great Red
Spot this storm is huge it can easily
fit the diameter of Earth within it it
has existed for as long as we've known
since it was first discovered in the
17th century it might very well be a
permanent feature of the planet but
interestingly it has decreased in size
since observations began the reason for
its reddish color is unknown and the
color of the spot can vary greatly from
brick red to Almost White the most
recent theory for its color is chemical
compounds being broken up by the UV
light from the sun much in the same way
as the process that happens on the rest
of the planet the storm is actually much
higher up in the atmosphere than the
surrounding clouds and as a result can
interact with the sunlight a lot more
this would explain why its color can be
much stronger than anything else around
it but Jupiter doesn't just have one
scientifically interesting storm another
storm known as red spot junr formed when
three storms merged into one between the
years of 1998 and 2000 and it has so far
pass unscathed by its bigger neighbor
and is now quite a prominent feature of
the planet it could last for another
couple of hundred years if it avoids the
same fate of a similar storm which
passed right through the heart of the
great red
spot so what do we think Jupiter is made
of well much like Saturn under the
atmosphere are Gus then liquid and their
metallic forms of hydrogen the further
into the planet you go the greater the
pressure becomes
under immense pressure hydrogen acts as
a metal and beneath that is an ice or a
rocky core because we can't recreate on
Earth the immense pressures Jupiter
experiences we don't really know what
properties these materials have at the
core roughly 90% of Jupiter is thought
to be hydrogen 10% helium and then Trace
Amounts of methane ammonia and
others Jupiter rotates very fast faster
than any other planet completing a
rotation in only 10 hours but due to it
not being solid it doesn't rotate the
same speed all over a rotation at the
poles taking 5 minutes longer than at
the
equator as a child I was very curious
why Jupiter wasn't a star considering
Jupiter is so massive plus it is
predominantly made of flammable hydrogen
surely someone just needs to throw a
match in to set it to light well the sad
news for my inner child is that stars
don't really work that way plus there's
barely any Oxygen on Jupiter to allow
for combustion stars produce their heat
from nuclear fusion caused by the
extreme pressures found at the stars
core current thinking is that Jupiter
would need to be roughly 75 times more
massive than it is now to be massive
enough to be a star although
interestingly its volume is isn't too
far off from the smallest known Red
Dwarf and yes you may have noticed in
this picture Jupiter does indeed have
rings nothing on the scale of Saturn but
there are four planetary Rings the main
ring is very thin but very bright the
rest quite wide but exceptionally faint
the main ring is about 6,000 km wide and
the only distinctive feature you will
see is what is known as the Met this
Notch something else to note about
Jupiter is its remarkably strong
magnetosphere it is 14 times stronger
than Earth due to the planet's liquid
metallic hydrogen Center this makes it
the strongest magnetosphere of any
planet in the solar system and is only
beaten by the sun's
sunspots there are a couple of reasons
why this is really interesting the first
is that magnetospheres channel solar
wind into the planet's pole which
produces magnificent Aurora the second
is that the four biggest moons of
Jupiter are protected from this solar
wind because they orbit within the
magnetosphere this implies they don't
need their own strong magnetospheres
because Jupiter is doing that for them
however this doesn't mean they are safe
from radiation Jupiter has a powerful
radiation band around it the same
radiation band that has crippled any
probe that went through it
the closest large moon to Jupiter IO
passes right through the heart of this
radiation band receiving
3,600 Ram per day on the surface for a
point of comparison anyone exposed to
this much radiation would be dead within
4 hours not the best home away from home
then when it comes to the Jovian moons
I'll only very quickly talk about them
because I have made a set separate video
about them here Jupiter has 67 known
natural satellites 51 are under 10 km in
diameter but the largest the Galilean
moons are some of the biggest in the
solar system they are IO Europa ganam
and Kalisto and they are all interesting
in their own right ganam is actually the
biggest moon in the solar system and has
a greater diameter than that of Mercury
and with this final thought take a look
at Jupiter through the infrared
demonstrating the immense size and power
of this planet this dot at the bottom of
the planet is the impact of an object
from space which if it had HD earth
could have spelled the end of our planet
as we know it we can be glad Jupiter is
there not only for its beauty but
because in so many ways it is an asset
to our soul
system thank you so much for watching
this far did you learn something today
about Jupiter you never knew before and
what planet remaster would you like to
see next on this channel for this series
let me know in the comments below and
I'll see you next
time I think most of us know what the
planets look look like in the visible
light spectrum Saturn's pale golden
color Jupiter's red bands and colorful
clouds and Neptune's dark blue
hue however light is emitted or
reflected by planets in wavelengths
beyond our eyes capabilities like
Infrareds and UltraViolets and often
what we can see in these wavelengths is
actually far more valuable to scientists
than simply how a planet would appear to
the natural eye that's because certain
things that are invisible to our eyes
might be very visible in infrared or
ultraviolet or vice versa and if we want
to know what substances are found on a
planet the electromagnetic spectrum can
help us again I'm Alex molan and you're
watching astrum and in this video I want
to focus on what we've seen through more
of the electromagnetic spectrum on
Jupiter and some of its moons and how
this different approach may give you a
new perspective on the largest planet in
our solar
[Music]
system just as a point of comparison
let's first look at how Jupiter appears
in natural light
the various spacecrafts that have passed
Jupiter have revealed it to be a
beautiful planet you will immediately
see a lot of the main Cloud deck of
Jupiter invisible light these are not
water clouds like on Earth but rather
ammonia ice clouds if you look closely
you can start to perceive the different
altitudes of these clouds the dark
narrow regions are actually Shadows cast
by the tall lighter colored clouds it
seems like the higher in altitude these
clouds are the lighter they become which
be seen in the highest altitude popup
clouds in this region which are snowy
white the process behind the different
colors in Jupiter's atmosphere isn't
completely understood but it's believed
to be caused by the upwelling of
compounds that originated deep within
Jupiter suddenly becoming exposed to the
UV radiation from the Sun as they lift
up to the highest altitudes in Jupiter's
atmosphere these compounds begin to
darken eventually sinking back down
again into the lower
altitudes but as you can can see
Jupiter's ammonia Cloud deck is opaque
we can't see through it if visible light
was the only wavelength of light we
could work with the vast majority of
Jupiter would remain a complete
mystery luckily we also have instruments
that can see beyond our eyes
capabilities and in certain wavelengths
of the infrared we can see Jupiter in a
completely new
light perhaps the most striking is to
observe Jupiter using the 4.68 Micron
wavelength as this shows the heat of the
planet very interestingly in this view
taken by the ger Observatory it is the
lower altitude reddish bands that are
the brightest you see Jupiter actually
emits more heat than it receives from
the Sun it is Contracting in size which
Heats it up this heat eventually makes
its way out of the planet through the
cloud deck the heat escapes easiest
where the cloud deck is thinnest which
is why features like the Great Red Spot
and the white bands invisible light are
dark in this
image luckily we aren't just limited to
a dis view of Jupiter either thanks to
the Juno spacecraft that is in orbit
around Jupiter right now viewing
Jupiter's poles in infrared again
scientists were able to create a 3D map
of the incredible vortices that are
found there Jupiter's North Pole has
nine seemingly constant vortices eight
in a square shape revolving around a
large one found right in the
center again you'll notice that it is
the lowest altitude regions that are
emitting the most heat because this
wavelength only reveals heat the haze
and shadows in the atmosphere don't
block The View as much as you would get
invisible light meaning it can give us
an unprecedented view of the 3D
structure of these vortices it's still
pretty cool here for Earth standards
even the yellow sections are only -3° C
with the darker higher altitude regions
being - 83°
c and because because the heat is coming
from Jupiter itself this view is
available to Juno night or day it isn't
reliant on
sunlight storms can show up in infrared
before they are noticed invisible light
too look at this comparison taken by
Hubble these near Earths siiz storms
located beneath the cloud tops are much
warmer than the ambient surroundings
indicating that internal heat does play
a big role in generating atmospheric
disturbances and while we're on this
wave length let's also have a quick look
at Jupiter's volcano Moon
IO unsurprisingly io's night side is
totally lit up by the volcanic activity
on its surface making it very easy to
identify new volcanoes and to keep track
of the ones we already knew about Juno
has had several looks at IO each one
revealing it to be a hive of activity a
truly hellish yet intriguing
World in fact all of the Galilean moons
have been examined in infrared but using
specific wavelengths which can reveal
different things for instance here is
the Galileo probe's infrared view of
Europa in the 1.5 Micron Water band when
viewing an object through this
particular wavelength we can see
locations where water is present the
deep blues in the image are the
locations of the purest water ice
whereas other colors indicate a mixture
of water ice with other minerals this is
called spectroscopy where you can
ascertain what molecule are on a planet
without actually having to land there
you see when white light reflects of a
certain atom or molecule that molecule
will absorb a band of light and reflect
the rest if we analyze the missing light
band we can know what the molecule is so
think of this image less as a photo but
rather as a graph of data indicating
locations of certain molecules colors
arbitrarily chosen by a scientist to
represent the data for instance
if we look at this image showing the
absorption band for sulfuric acid it is
the brighter regions this time that show
where the abundance of sulfuric acid on
euroba is this abundance is found around
the surface's cracks so it may come from
the ocean below the crust but it's also
found on the trailing side of Europa
seen on the top left of the image it
seems that as Europa orbits it is
bombarded by sulfur ions incredibly this
sulfur probably originated from the
eruptions of IO
volcanoes if we look at a crater on
Kalisto infrared data has been overlaid
onto a visible light
image Reds indicate more water ice Blues
show less this is pretty interesting as
this is one of the highest resolution
infrared images we have of a body around
Jupiter this image only being 200 km
across it adds a lot of information you
wouldn't get from the visible light
image namely there's a concentration of
water water in the crater but a ring
directly around it where no water is
present and then water appears again in
this Ray system coming away from the
crater the icier regions come from the
impactor exposing the ice beneath the
surface but while there's a ring between
the center crator and the debris from
the ray system is a bit of a mystery
perhaps the icy debris from the impact
didn't start hitting the ground until it
reached this distance out in any case
this image shows that non- ice materials
only make up a thin layer on the top of
the surface of
Kalisto and what does Jupiter look like
through certain bands of infrared this
image is really interesting the top left
and right images are taken in 1.61 and
2.73 microns respectively in these bands
we can see the cloud deck similarly to
what we can see inv visible light
however in the middle we are looking
only through 2.17 microns the absorption
band of hydrogen as we know Jupiter is
predominantly hydrogen meaning the
hydrogen in the atmosphere suddenly
becomes opaque and visible in this
wavelength in fact the only features
still visible are the really high
altitude clouds the ones that poke
through most of the hydrogen in the
atmosphere the bottom left image is the
3.01 Micron band where there is some
absorption but not as much at this band
it is methane and ammonia that are
absorbing the light bottom middle is at
4 4.99 microns giving us another heat
map and bottom right is a false color
combination of all five images which is
what you see happening If Ever I show a
false color image in one of my videos
now you know what these false color
images are trying to
show the last interesting view of
Jupiter I want to show is in the
ultraviolet absorption spectroscopy in
the ultraviolet isn't super useful in
planetary astronomy the only time I can
think of it being actively used on
Jupiter was to track the impact of comet
Shoemaker Lev 9 back in
1994 there the dust absorbed a lot of
the UV sunlight and so scientists could
easily track winds in the planet
Stratosphere by watching the evolution
of these
features however molecules that are hot
enough will emit light in lots of
different wavelengths and there is a
bright source of light coming from
Jupiter in ultraviolet and infrared it's
auroras Jupiter's auroras are extremely
powerful compared to the ones on Earth
and are a permanent feature on the
planet Hubble which can see in
ultraviolet has been tracking Jupiter's
auroras for years although the best
views have come from Juno in the
infrared simply due to Juno's orbit
taking it over the planet's poles
whereas Hubble's viewing angle makes
observations difficult these auroras are
strongly influenced by the magnetic
field environment of Jupiter streaming
particles into its upper atmosphere plus
from the flux tubes between it and its
moons so there we have it a look at
Jupiter in a very different way than
what you may be used to and as you can
see absorptions and fluoresence through
spectroscopy can help us understand a
planet far more than what only visible
light can reveal we can determine
molecules and minerals observe a
planet's heat map and view Aurora
interacting with the planet's
magnetosphere everything together helps
us get a more complete picture of how a
planet works and why it behaves the way
it does what more videos about this for
the other planets let me know in the
comments
Below in July of 1994 scientists around
the world watched in amazement as the
comet Shoemaker Levy 9 smashed into
Jupiter the impact's blast was so
powerful that it Unleashed a force
equivalent to 300 million atom bombs for
6 days Jupiter was throttled by 21
separate impacts from the Comets
fragments which produced Giant glooms of
debris that Rose 3,000 km above the
cloud tops an impressive feat
considering Jupiter's immense gravity
and heated Jupiter's atmosphere to
temperatures reaching 30,000 de C at the
moment of impact the comet was traveling
at a blistering speed of
216,000 kmph with its largest fragment
spanning 2 km in diameter the impact
raised huge clouds of debris that were
visible for months and left a scar in
Jupiter's atmosphere spere more
prominent than its great red
spot now collisions of this magnitude
aren't entirely unheard of our solar
system is littered with evidence of
major impacts from comets and asteroids
scientists believe Earth was hit by a
massive asteroid at the end of the
Cretaceous Period which likely led to
the extinction of the non-avian
dinosaurs but these events are extremely
rare meaning the chance to see one in
action is a once in a-lifetime
Opportunity so what did it look like and
does the incident shed light on the odds
of a similar event happening here on
Earth I'm Alex molan and you're watching
astram join me today as we relive the
biggest planetary explosion ever
witnessed from space and unpack what it
taught us about Jupiter and planetary
collisions in 1993 astronomers Carolyn
and Eugene Shoemaker and David Levy were
conducting research at California's
Palomar Observatory when they discovered
a periodic Comet that had been captured
by Jupiter's gravitational pull periodic
means that the comet has an orbital
period of fewer than 200 years this was
unusual as most comets in the solar
system orbit the sun however Jupiter is
so massive being the largest of the
eight planets by far that its ability to
capture other objects approaching its
orbit isn't surprising a lot of
Jupiter's irregular moons are likely
captured asteroids and comets that have
since burned off their volatile material
on their
surfaces but this Comet also had other
unusual characteristics for one it was
big so big that scientists think that
the frequency of similar impacts is a 1
in 6,000 year occurrence but the comet
was also fragmented most likely torn
apart by Jupiter's tidal forces on a
previous approach most striking of all
however was his highly eccentric orbit
eccentricity measures the deviation of
an orbit from a circle with zero being
the value of a perfect circle and one
being the upper limit of when an
elliptical orbit becomes hyperbolic
Shoemaker Lev 99's orbit had an
eccentricity of over
0.998 in other words extremely eccentric
almost immediately astronomers realized
there was a possibility the comet would
collide with Jupiter but their suspicion
turned into certainty once they
collected more precise Data before long
astronomers knew the impact would occur
sometime in July 1994 and pretty soon
the whole world was waiting for the
event with baited
breath anticipating SL 9's impact
astronomers monitored its movements from
The kek Observatory Germany's rossat
x-ray telescope and NASA's Hub Space
Telescope among other instruments but
when the first of the Comets fragments
hit on July 16th 1994 the worst case
scenario occurred it looked like we
would miss the spectacle you see sl9
trajectory meant the impact would occur
on the side of Jupiter facing away from
us that meant none of Earth's high power
telescopes were in position to view the
initial impact for scientists this would
have been a crushing disappointment but
as luck would have it not all our
cameras were located here on Earth by
sheer chance NASA's Galileo spacecraft
launched in 1989 was only one year out
from Jupiter at the time of SL 9's Final
Approach it just so happened to be in a
perfect position to record the impact as
it happened but Galileo wasn't our only
helper from afar the ulyses spacecraft
which had been launched in 1990 to
monitor the sun was also pointed at
Jupiter and even NASA's Voyager 2
located 44 astronomical units away was
programmed to monitor radio emissions
from the crash site with his ultraviolet
spectrometer each Pro paused its own
missions to work together on this to
help us witness an extraordinary event
shortly after fragment a impacted
Jupiter Galileo saw a massive Fireball
erupt reaching as high as 24,000 de C
its plume quickly Rose 3,000 km which
would make it as big as Australia from
north to south this was surprising a
scientist hadn't expected to see
Fireballs in the aftermath of the
Collision a few minutes later masses of
ejected debris plummeted back towards
Jupiter's surface and burned up again
turning Jupiter's atmosphere into a
raging furnace before long Jupiter's
rotation brought the impact site into
view of Earth allowing high power
telescopes like Hubble to view a huge
Dark Spot on Jupiter as it happens
Jupiter's rotation is fast with days
that last only 10 hours contrary to what
you might think larger planets tend to
have shorter days than smaller ones the
comet's impact set off shock waves which
rippled across Jupiter's dense
atmosphere at the speed of 4 450 m/
second and all this was just from the
first impact for 6 days between July
16th and July 22nd the Comets fragments
bombarded Jupiter the largest coming on
July 18th when fragment g hit its impact
alone produced a blast 600 times more
powerful than the world's entire nuclear
Arsenal leaving a huge dark spot one
Earth diameter
across however as spectacular as the
initial impact was the comet's aftermath
proved just as valuable by studying the
clouds of debris scientists gained an
unprecedented window into Jupiter's
atmosphere and its movements in addition
they caught a neverbe seen glimpse of
Jupiter's composition beneath its dense
Cloud tops as spectroscopic readings
were able to identify material that had
been splashed upward by the comet's
impact they detected diatomic sulfur and
carbon disulfide and heavy elements like
like Silicon iron and
magnesium interestingly they also
detected substantial amounts of water
something they weren't necessarily
expecting in fact one of NASA's Juno
probe's primary objectives is to locate
where this water is hiding in Jupiter's
atmosphere however one of the more
disturbing implications of the impact
was the realization that large celestial
bodies could still hit
planets one school of thought theorized
that major Comet and asid collisions had
been a lot more frequent earlier in the
Solar System's existence but Shoemaker
Lev 9 made it clear that very
destructive collisions were still
possible had it happened by chance and
we witnessed an extremely rare event or
does it happen more than we thought
remember we've only had the technology
to see this kind of event within the
last 80 or so
years if a comet as large as sl9 were to
crash here on Earth it would lead to the
extinction of most life on the planet
this had a dramatic effect on our
Collective psyche as anyone who lived
through the '90s can attest it was also
a wakeup call for NASA and for various
defense agencies before sl9 the term
planetary defense didn't exist but in
its wake NASA took up the mission of
monitoring near Earth objects or NEOS
with the goal of identifying upwards of
90% of asteroids in our Celestial
neighborhood greater than 1 kilometer in
diameter
having achieved this goal NASA is now
well on its way toward identifying
asteroids greater than 140
M but before you stay up all night
worrying be aware that these events are
undoubtedly rare and there is perhaps
one other s aligning to SL 9's impact
you see Jupiter is a massive planet with
a powerful gravitational influence and
since it is also one of the outer
planets some scientists now think it
might act as a cosmic vacuum cleaner of
sorts we know that Jupiter gets
approximately 2,000 to 8,000 times as
many cometry impacts as Earth so perhaps
one of the reasons extinction level
impacts are so uncommon here on Earth is
that Jupiter had been a magnet for these
kinds of comets and asteroids this
argument has even become part of the
rare earth hypothesis which suggests
that Earth is host to a unique set of
conditions without which the evolution
of complex life would be impossible not
everyone agrees with this hypothesis
though and in any event was still a long
way from proving
it so while we might not know the exact
likelihood of a massive Comet or
asteroid hitting the Earth the impact of
sl9 with Jupiter has certainly Advanced
our understanding of these events
moreover it was without question a
spectacular moment that treated watches
to one of the most impressive action
scenes ever witnessed by human eyes
maybe one day we'll have the chance to
see something bigger but hopefully from
not too close while there have been
other explosive events like the 2022
Tonga volcanic eruption for now the
winner is clear the biggest explosion
ever seen on a planet is Shoemaker L9
and by comparison the competition looks
like a drop in the
bucket while the planets get a lot of
the attention in school and by space
agencies agencies there are smaller less
known worlds in our solar system that
are just as
interesting four of them are known as
the Galilean moons Jupiter's four
largest
moons considering they are so close
together they are fascinating because
they are so different you have a volcano
Moon a moon that has one of the best
chances of containing life out of
anywhere else that we know of the
biggest moon in the solar
system and an ancient scarred Moon whose
surface can be traced back to the solar
systems very
beginning I'm Alex molan and you're
watching asram and in this video we will
go through the special worlds one by one
and do a deep dive into what makes each
one so unique by the end of this video
I'm sure you'll understand why they will
be the subject of two missions this
decade from both NASA and Issa we'll
start with the innermost Moon
IO let's get to know the context of IO a
little better Jupiter has 79 moons that
we know of so far there's a few that
orbit close to the planet in and around
the planet's rings beyond that are four
large moons known as the Galilean moons
named after Galileo who discovered them
in
1610 from innermost to outermost these
moons are IO Europa gamid and
Kalisto Beyond them are The Irregular
moons of Jupiter all of which are much
further out than the previous Moon
IO orbits very close to Jupiter only
350,000 km above Jupiter's Cloud Tops
This Means from io's surface Jupiter
would appear 39 times bigger in the sky
than our moon IO orbits Jupiter in only
42.5 hours compared to our Moon's
monthly
orbit at some points in its orbit the
tidle Bulge on iO is thought to be up to
100 m this effect is similar to what we
see on Earth with the ocean tides being
caused by the moon although on Earth the
effect is much more minimal the tides
only usually shifting about 2 m from
high to
low IO is getting 300% more tidal force
exerted on it in comparison to our moon
on us because of its close proximity to
the biggest planet in the Solar System
Jupiter and the other big moons in the
system don't allow the moon's orbit to
be any less exent Centric meaning IO
isn't going to be getting any rest bite
anytime soon a day on iO is the same as
its orbital rotation which means that IO
is tidily locked to Jupiter just like we
can only see one face of our moon from
Earth only one face of IO can ever be
seen from
Jupiter IO is a pretty big moon although
it is the second smallest out of the
Galilean
moons it is comparable in size to
Earth's moon and shares a similar
density meaning it has a similar amount
of gravity but interestingly it does
have the highest density of any other
moon in the solar system one of its many
unique features another is that it is
composed of mainly silicate Rock and
iron similar to the terrestrial planets
and our moon in comparison to most other
big moons in the solar system which are
made of water ice and
silicates IO in fact has the least
amount of water of any known body in the
solar system its core is likely to be
made of iron or iron sulfides surrounded
by a silicate Rich mantle and crust the
core is not thought to be convec in
though as no magnetosphere has been
detected around the moon the mantle is
thought to be liquid near the crust and
is at least 50 km thick this is where
all the volcanism
originates which brings us to perhaps
the most interesting part about IO the
hundreds of huge volcanoes all over its
surface before the 197s we didn't know
much about IO at all although telescopes
were starting to pick up hints that the
moon was devoid of water and that it may
have a surface of
sulfur the first mission to see IO in
any kind of detail was Pioneer 11
although the quality was still not
great what it did detect however is that
IO was made of silicate Rock and not
water ice and that it has a thin
atmosphere Pioneer 10 was also meant to
take some close-up shots of IO but this
was lost due to Jupiter's radiation
interfering with the onboard command
system the radiation Pioneer 10 went
through was 10,000 times stronger than
the maximum radiation around the
earth the next missions to Jupiter were
the Voyager one and two missions in
1979 Voyager 1 flew by at a distance of
only 20,000 km and was able to take some
impressive closeups of IO surface what
it saw was a remarkable landscape full
of vibrant colors and a total absence of
impact crators it found mountains taller
than
Everest as well as volcanic pits
hundreds of colomet wide and what look
to be lava
flows most notably however was the
presence of plumes coming from the
surface this proved that IO is
volcanically active and it is still the
first and only place this has been
visibly seen beyond Earth not including
cryo
volcanoes Voyager One also confirmed
that the surface of IO is covered in
different sulfur frosts this is what
gives IO its many spectacular
colors it founds that it is these sulfur
compounds that dominate the atmosph
spere for to two also saw IO in July of
1979 but was much further away at 1
million km although it still saw seven
of the nine plumes Voyager one saw in
March which meant those volcanoes had
likely remained active throughout those
four
months the really interesting images
came about with the Galileo spacecraft
that arrived at Jupiter in 1995
the spacecraft wasn't especially
designed to study IO but it was able to
acquire some of the highest resolution
images we now have of its
surface sadly though Galileo never
worked at full capacity as it had quite
a few mechanical malfunctions which
means we could have had even better
images had it been fully operational
what it was able to see though were
plumes from many
volcanoes as well as confirming the
volcanoes were erupt in Sulfur and
silicate
magmas similar to what we have on earth
except the magma on iO is also rich in
magnesium the surface of IO is
spectacularly colorful the yellow ples
are composed of mainly sulfur the white
areas are mainly fresh sulfur dioxide
frosts towards the poles the sulfur is
damaged by radiation which can be seen
as the poles appear redder than the rest
of the planet in other places the colors
of red are the deposits left by volcanic
plumes that reached hundreds of
kilometers above
IO the most obvious deposit is from the
volcano Pelle sadly an inactive volcano
when Galileo was around but Voyager 1
was able to see a massive plume when it
passed by in this image this plume is
300 km tall and 1,200 km wide in other
words roughly the size of
Alaska interestingly though the source
of lava flows on Earth are typically the
depression you would normally see at the
top of volcanoes but these depressions
are not found on high peaks on iO
instead you have these Lava Lakes with
high walls along the outside here is
Loki the largest volcano depression on
iO 200 km in
diameter these legs are directly
connected to the lava Reservoir below
but usually have a thin layer of
solidified crust on top on average Loki
produces 25% of the average heat output
of IO but sometimes the crust on the
Lava Lake sinks back into the lake
causing Loki to produce 10 times more
heat than
normal this can especially be seen in
one of io's other big volcanoes
tasa normally this area looks like this
but here the crust is seen falling into
the lava lake in this image where there
is just white the radiant energy from
the lava curtain was so intense that the
camera only registered
white in 2007 New Horizons used Jupiter
as a gravity assist on its way to Pluto
it also used the opportunity to test its
equipment it focused its lens on iO
during its flyby and what it saw was
amazing tashar the volcano I just
mentioned was in full eruption and the
plume could be seen hundreds of
kilometers above io's surface you can
also see smaller eruptions around the
Moon I must admit this is one of the
most impressive things I've ever seen of
space even though the volcanoes tend to
be flat it also has some extremely tall
mountains the highest one reach in 18 km
tall these mountains tend to to be
completely by themselves not as part of
a ridge or a range although most are not
volcanoes Lava Lakes are found near them
indicating there are faults in the crust
near these
mountains another of the unique aspects
of IO is its interaction with the
magnetic field of
Jupiter Jupiter has an extremely large
and strong magnetic field and IO orbits
within some of the strongest sections
the unusual thing about this interaction
is that when particles from some of io's
thin atmosphere and its eruptions are
lost to space these particles float in
orbit around Jupiter in what is known as
a neutral Cloud This Cloud can extend
far beyond and behind the orbit of IO
but also surrounding Jupiter is
something known as a plasma Taurus a
donut of ionized particles that follows
the rotation of Jupiter's magn magnetic
field the plasma Taurus rotates a lot
faster than io's orbit at 70 km a second
compared to iio 17 km a second orbital
velocity IO orbits right through the
middle of it with the particles from the
Taurus bombard in the particles in the
neutral Cloud exciting them to higher
energies these newly ionized particles
feed into the Taurus attracted by the
magnetic field lines of the
magnetosphere these particles are lost
from the neutral Cloud into the plasma
Taurus at a rate of about one ton of
matter per second which greatly
increases the size of Jupiter's magnetic
field in fact if it was visible
Jupiter's magnetosphere would be about
the same size as the moon in our
Sky io's interaction with Jupiter
doesn't end there Jupiter's magnetic
field lines which IO crosses couple io's
atmosphere and Neal Cloud to Jupiter's
polar upper atmosphere by generating an
electric current known as the io flux
tube a flux tube is basically a
concentration of magnetic field lines
the sun has these between sunspots and
it's very visible on the sun because of
the charged plasma that flows between
them io's flux tube causes an aurora
Trail around Jupiter's poles this point
here is the flux tube from IO striking
the upper atmosphere of
Jupiter Aurora are also visible on iO
although they are not just limited to
the poles the different colors represent
the different particles being ionized
green is sodium red is oxygen and blue
from
sulfur
Europa one of the most exciting moons in
the entire solar system it is a
beautiful world filled with with
Mysteries this is the first ever closeup
image of Europa taken by the Pioneer
probe back in
1973 since then we've had the Voyager
and Galileo probes explore the moon and
with each visit Europa has never failed
to surprise us we are yet to solve a lot
of europa's puzzles but there are many
things that we are starting to piece
together let's first of all see where
Europa fits into the Jovian system
Europa is the second and smallest of the
four Galilean moons although it's still
the sixth biggest moon in the entire
solar system just behind Earth's moon
with a diameter of about 3,000
km it takes Europa 3.5 days to orbit
Jupiter once interestingly the first
three Galilean moons IO Europa and ganam
are locked in a 421 orbital resonance
due to their gravitational influence
with each other this orbital resonance
and the constant gravitational tugging
from the other moons keeps the orbit of
Europa from ever becoming completely
circular due to europa's slight
ecliptical orbit the magnitude of the
gravitational force acting on it from
Jupiter increases and decreases as it
orbits this creates tides that stretch
the moon's surface these forces are
significant as they have a big influence
on the moon's appearance and what goes
on under the surface
europa's surface is made predominantly
of water ice as you can tell it looks
very remarkable and distinctive due to
these long continuous fractures and
cracks these are called lineer which
translates to lines in Latin these
lineer are often only about 1 to 2 km
wide but can extend for thousands of
kilometers across the moon's surface we
aren't sure how or why these linear are
formed at present but the most likely
theory is that as the crust pulls apart
from tidal flexing warmer material from
beneath fills the Gap in a similar
fashion to the ocean ridges on
Earth in this image taken by the Galileo
spacecraft you will notice some dark
brown spots they are very small only
about 10 km across and they are known as
lenticula they are also believed to be
formed by the upwelling of hot less
dense material to the surface either by
pushing the existing crust up or by
breaking through altogether should the
underground material have broken through
what we can then see are these strange
unusual terrains called chaos terrains
they are really rough patches surrounded
by a rather smooth surface these spots
are expected to be soft and may contain
significant information about what's
under europa's surface which we will get
to later in the
video data from Galileo also indicated
that europa's equator may be covered in
icy spikes called
penitentes these vertical cracks may be
up to 15 M high and will have formed
from direct overhead sunlight on the
equator interestingly penitentes are
found on Earth too in dry regions at
high altitudes although nowhere near as
large as on
Europa despite being roughly the age of
the solar system Europa barely has any
craters Europa has less than 50 major
craters whereas the Earth's moon has
more than 5,000 craters with a diameter
above 25 km this indicates that europa's
surface is constantly changing and
reforming models suggest that europa's
surface is only about 30 to 180 million
years old which is very young in
geological terms additionally europa's
icy surface is the smoothest surface of
any known solid celestial object in the
entire solar system its icy crust also
has an albo or light reflectivity of
0.64 one of the highest of all the moons
europa's albo makes it five times
brighter than our
moon the surface is bombarded by a
constant and intense blast of radiation
from Jupiter the radiation level at the
surface of Europa is equivalent to a
dose of about 5,400 MZ per day exposure
to radiation at that level would be
enough to kill a human in a single day
the reddish brown color spread across
the cracks and fractures of the moon is
believed to be due to salt and sulfur
compounds mix in with water ice and then
Modified by Jupiter's
radiation a recent study from JPL
suggests that Europa might even glow in
the dark energetic ions from the
radiation penetrates the surface which
would energize the molecules beneath
which would make them release energy as
visible light unfortunately we cannot
see europa's Dark Side from Earth as we
are between it and the sun always so we
are going to have to wait for future
missions to Europa before we can prove
this radiation received from Jupiter
plays a significant role in europa's
atmosphere as well Europa has a very
tenuous atmosphere composed primarily of
oxygen andlike on Earth the oxygen on
Europa is formed by radiolysis or in
other words the process of radiation
bump barding the water ice surface
separating the H2O into oxygen and
hydrogen hydrogen escapes europa's
gravity alt together because it's so
light whereas a lot of the heavier
molecular oxygen Remains the hydrogen
and oxygen that escape europa's gravity
form a disperse neutral Cloud which
follows the orbit of Europa around
Jupiter in 2012 the Hubble Space
Telescope discovered plumes of water
vapor around erupting from europa's
South Pole this image suggests that the
water plumes rise up to 200 km from its
surface in 2018 astronomers found
additional evidence of water plume
activity on Europa when they looked back
at the old Gallo data with a new data
analysis technique a dedicated Mission
studying these plumes can also help us
understand what's inside the moon
without having to land on it because
what may lie underneath that solid ice
surface is perhaps the most fascinating
thing about Europa there is likely to be
a global Ocean between a Rocky manle and
the water ice crust the first clue that
this amazing ocean world was hidden
under its surface was provided by the
Voyager and Galileo probes in 1979 and
the late 1990s
respectively between these missions
there was a drastic change in the
magnetic field of the Moon which is not
possible unless there is some
electrically cond inductive fluid
beneath its surface europa's crust also
indicates the presence of a liquid layer
beneath it as it rotates with an angle
of 80° which is not possible if the
crust and Rocky mantle were mechanically
attached instead it is likely that the
icy crust floats on the ocean and it is
believed to make one full rotation
around the Moon once every 12,000 years
the fact that this ocean is not attached
also explains the multitude of lineer on
the
surface tidal flexing should cause
lineer to form at specific points on
Europa not all over however because the
position of the crust changes over time
and one spot never stays in the same
place for long hence why more and more
linear
form Europa is 780 million km away from
the sun which is five times further away
than the earth that makes the sunlight
about 20 five times fainter here as such
Europa or any other moon in the Jovian
system for that matter barely receives
any heat from the Sun so unsurprisingly
it's cold enough here that the surface
is Frozen in fact europa's surface
temperature averages about
-60° C at the equator and- 220° C at the
poles keeping europa's icy crust as hard
as
Granite however tidal press presses
exerted on the moon as it orbits Jupiter
Heats europa's core so geothermal
activity from the core should keep the
subsurface ocean in a liquid state this
ocean is believed to be under only 15 to
25 km of solid frozen crust the ocean
itself is probably about 60 to 150 km
deep interestingly Europa is only 1/4
the diameter of Earth although it may
contain twice as much water as all of
Earth's oceans
combined what's most interesting about
europa's ocean is that scientists
believe that it is in contct with
europa's silicate Rocky mantle this
makes europa's ocean as suitable
environment for Life as we know it to
exist we believe that life requires
water minerals and energy to form and
Europa seems to have all these
requirements from the evidence we've
seen so far scientists are extremely
confident that this ocean not only
exists
but that chemical reactions can take
place there and that there is enough
tidal energy heating the core that
geothermal activity may exist on this
Ocean's floor as we have seen on Earth
whole ecosystems can exist in such
places far from the Sun's light so for
now Europa is one of the most likely
places we can find life outside of Earth
now NASA's Europa Clipper spacecraft is
scheduled to launch in 2022 and is
likely to reach the Moon by the end of
the decade it is scheduled to perform
more than 42 flybys of Europa Issa is
also working on their own spacecraft
called juice or Jupiter icy moons
Explorer which will explore Jupiter and
three of its largest moons ganam Kalisto
and Europa juice is also scheduled to
launch in 2022 and is also likely to
reach the Moon by the end of the decade
these probes are specifically designed
to examine europa's water water plumes
an atmosphere NASA is also planning a
Europa Lander Mission but this mission
is going to launch well after the Europa
Clipper Mission these missions will help
us know more about Europa and hopefully
confirm the answer to the most
tantalizing question of all does it and
can it sustain life at the very least
these missions will give us a new
perspective of our solar system and help
us understand how it
works so there we have it almost every
anything you could want to know about
the fascinating world of
Europa
ganam the third of Jupiter's Galilean
moons the largest moon that we know of
and home to the largest water ocean in
the solar
system but there's something else that
sets gamed apart from anything else
we've seen before this Jovian giant
contains an intrigued mystery buried
deep beneath its
surface there are 79 different moons of
Jupiter and ganam is the third of a
group known as the Galilean moons ganam
is the largest of these four with an
impressive diameter of
5,268 KM for a point of comparison this
is 0.41 times the size of Earth's
diameter and 1.02 times greater than the
previously thought to be largest moon
Titan it initially appeared bigger
because of its thick atmosphere which
stretches hundreds of kilometers into
space ganim's volume is even 26% larger
than Mercury's although it doesn't
contain as much mass ganim's average
density is 1.9 G per cm cubed compared
to Mercury's
5.4 this is because of its
composition like Europa ganam surface is
a thick crust of water ice extending 150
km deep underneath which is believed to
lie a vast ocean of liquid water and
when I say vast it really is because
while mercury has very little water and
is rich in dense Metals the abundance of
water on ganam reduces its average
density the ocean of ganam is so big
that it contains more water than all the
oceans and seas on Earth and it is
estimated to be 100 km in depth on
average 10 times deeper than the deepest
point in our
ocean all of this water means that ganam
is only 50% Rock the rest being water
and small amounts of metals and other
ices this seems appropriate to me as the
name ganam comes from the classical
mythology where Zeus or as the Romans
called him Jupiter claimed a young boy
called ganam and took him to be a cup
Bearer for the gods it seems fitting
that the moon ganam would also carry so
much water around for
Jupiter interestingly ganam has an
atmosphere that can contains oxygen now
you might be wondering with all this
water and an oxygen atmosphere is it
possible that life exists on ganam while
it's certainly possible there are some
features of ganam that make this
unlikely to begin with the oxygen
atmosphere is very thin it is estimated
to be somewhere between 0.2 to 1.2 micr
pascals or about 100 billion to 500
billion times less than Earth's
atmospheric pressure at sea level that
would be impossible to breathe and while
our own planet earth has certainly
demonstrated that ecosystems can
flourish in the depths of oceans without
sunlight to sustain it there could be a
big problem that prevents this from
happening on ganam this is because the
ocean of ganam is so deep that water
down at its bottom would likely be
compressed back into an ice through
sheer pressure life in the deepest parts
of our ocean can survive thanks to
minerals being ejected from geothermal
vents with such a thick ice layer
between the core and the ocean it is
unlikely that this would occur on
ganam Europa ganim's neighboring moon is
considered a more likely candidate for
life because of this however if ganim's
ocean is salty which there is an
increasing amount of evidence for it
could change the interior makeup of
ganam drastically models suggest that
with a salty ocean it could be that
there are multiple layers divided by
sheets of ice if this is the case the
most internal layer could indeed be in
contact with the rocky core increasing
the chances of Life existing there but
underneath ganim's ice and water exists
something else truly surprising
something that scientists do not have an
explanation for somehow ganam is
producing a magnetic
field the magnetic field of ganam was
first discovered by scientists in 1996
when the Galileo spacecraft began a
series of flybys of the icy Moon the big
indicator of a magnetic field is the
presence of auroras and Incredibly
auroras were detected in ganim's tenuous
atmosphere not only that but as Hubble
studied ganam over an extended period it
became clear that these auroras didn't
wobble as much as expected likely a
result of something known as magnetic
friction in a salty water ocean under
the
surface a magnetic field is significant
as it the feature on Earth that shelters
the planet from solar radiation enabling
all life to flourish the field around
ghami does not completely protect it
from such radiation being tucked within
Jupiter's incredibly powerful magnetic
field and radiation belt means it's
still getting pelted with a lot of
radiation gamine surface still has about
5 to8 REM enough to make a human
severely ill or dead in Just 2 months
but it's still better than its closer
orbiting neighbor moons
scientists are not quite sure why this
magnetic field is here at all our
planet's core is hot and malten
convection currents within it move
electrons which in turn produces the
magnetic field that surrounds us here
however this shouldn't be happening on
gamed gamed is smaller than Earth and
given its size and composition
scientists believe that the core should
have cooled down enough by now that it
should be a solid Mass not liquid this
would prevent electron moving through
convection and would prevent a magnetic
field and none of the other moons of
Jupiter have a magnetic field in fact
ganam is the only moon in the entire
solar system that has one so what's
going on scientists do not know for sure
but the answer might lie in ganim's
incredible relationship with its planet
and neighboring moons and a process
known as tidal heating ganam orbits
around Jupiter roughly once every 7even
days in an eccentric orbit this means
that at some points of its orbit it's
closer to Jupiter than at others when an
object comes under a strong
gravitational force it will stretch in
the direction of that Force as mass is
pulled in the direction of gravity
however the further an object gets from
the source of gravity the more it will
compress back to its original shape as
ganam has an eccentric orbit around
Jupiter it is constantly coming under
more and then less gravity and is
constantly stretching and
Contracting have you ever pulled and
stretched blue tack repeatedly in your
hands before pushing it back to a ball
shape then you might have noticed that
after a while it gets surprisingly warm
this is because stretching produces
friction as the material rubs up against
itself and on the scale of moons and
planets this friction adds up a tidal
Force creating heat through friction is
known as tidal heating on top of that in
a process I find fascinating G has
formed an orbital resonance with two of
its fellow Galileo moons IO and Europa
in what is called a laas resonance for
each time ganam orbits Jupiter Europa
will orbit exactly twice and IO exactly
four times this mathematically precise
configuration has not happened by
coincidence but is evidence of the
moon's gravities pulling on each other
and the whole system attempting to
conserve the resulting momentum however
it means that ganam is constantly being
P by its neighbor's gravity and is under
a lot of gravitational stress so perhaps
tidal heating is warming up ganam enough
that its core remains a liquid after all
helping it to continue to produce its
magnetic field scientists do not know
for sure but it would perhaps explain
why the surface of ganam is so
interesting you may have noticed that
ganam surface is split into large dark
regions that cover about a third of its
surface and lighter regions that make up
the other 2/3 through examining the
number of impact craters on these two
sections scientists can tell that the
dark regions are actually older than the
lighter ones as they contain more
craters the lighter regions might have
fewer craters but they do contain long
ridges and grooves up to 700 M high and
thousands of kilom long truly an
impressive sight but again scientists
are not sure how these ridges formed one
explanation is that tidal forces is
stretched out the surface of the Moon in
an unstable period of ganim's ancient
history perhaps this same tidal Force
could have also warned ganim's core and
preserved its magnetic field whatever
its cause the magnetosphere of ganam has
been instrumental in helping scientists
understand the composition of the Moon
by measuring the areas that Aurora
appeared in ganim's atmosphere
scientists were able to confirm the
existence of ganam subsurface oceans all
without having set foot there and as for
the rest of ganim's mysteries maybe
juice
the Jupiter icy Moon Explorer will find
us the answers the EA spacecraft is set
to launch in 2022 and though it won't
reach orbit around ganam for another 10
years after that is to investigate the
inner workings of a number of Jupiter's
moons including ganam until then we may
have to let ganim's Mysteries remain
just that a
mystery
Kalisto despite the fact it is the third
largest Moon that we know of I think the
majority of people would be hard pressed
to say any facts about it at all is it
just a boring world or do we simply not
know much about it actually we know more
than you may first assume and it is far
from
boring let's start with where it fits
into the Jovian system Kalisto is the
third largest moon in the entire solar
system and it's just smaller than
Mercury at
4,820 km across however while its
diameter is only 58 km less than
Mercury's it is only 1/3 of the mass of
the planet meaning it's less dense and
its gravity is a lot weaker it is the
second largest of the Galilean moons and
orbits Jupiter much further out than the
other three taking 17 Earth days to do
so at an average distance of 1.9 million
km even at this distance it is still
tidily locked with Jupiter meaning the
same side of Kalisto always faces its
parent
planet however it does mean that it is
not locked in an orbital resonance with
the other three moons nor do we believe
that it ever
was Kalisto has a very tenuous
atmosphere composed of carbon dioxide
and possibly oxygen too although oxygen
has never actually been detected yet we
know however that the atmosphere is so
thin that the molecules contained within
it do not Collide and theoretically
basically the atmosphere should be
Stripped Away by atmospheric loss
processes in Just 4 years scientists
believe that kalisto's crust is
replenishing the Lost atmospheric
particles through sublimation of carbon
dioxide surface ices evidenced by some
interesting surface
features now the surface of Kalisto is
one of the most ancient in the solar
system with evidence placing it at over
4 billion years old you'll immediately
notice the speckled nature of Kalisto
it's surface is completely covered with
various sized impact craters more so
than any other object we've observed in
fact it's close to saturation any new
crater will probably just overlap
another one at this point without any
geological activity cratering is perhaps
the only process that has vastly been
impacting kalisto's appearance over its
lifetime why is kalisto's surface so old
compared to a lot of other bodies in the
solar system well on geologically active
planets like Earth there are processes
that can erase almost all evidence of
past impacts Earth has one of the least
created surfaces in the solar system
because so much happens on its surface
it has weather water plants volcanism
tectonic plates and human activity these
act together to break apart wear down
and lift up the ground even other Jovian
moons like Europa or IO have
comparatively fewer craters thanks to
the tidal forces which cause geological
activity on their
surfaces this doesn't happen with
Kalisto Kalisto does not show any signs
of geological processes such as
volcanism or plate tectonics and so its
surface has remained intact after all
these
years limited tidal forces and thus no
geological activity impact Kalisto in
another very unique way there are no
mountains to speak of on its entire
surface when Kalisto initially formed at
the very beginning of the solar system
it was likely an ocean world that has
since frozen over and apart from the
bombardment of meteors it has stayed
exactly the same ever
since so let's have a look at some of
these craters because some of the
biggest are truly impressive
structures this is Asgard the second
largest impact crater on Kalisto
measuring 1,600 km in
diameter and this is Valhalla the
largest multi- ring impact crater in the
entire solar system with a diameter of
3,800 km it's these craters that add to
the unique appearance of Kalisto as they
contain more rings than craters anywhere
else with these craters the impactor was
large enough that it may have completely
punctured the thin crust with it
eventually refreezing over in the light
patches you see in the middle zooming in
on these middle regions you'll notice
they have a mtle
appearance there seems to be a big
difference in contrast between the
bright knobs and the darker plane these
regions are a lot less crated than the
rest of kalisto's surface which would
make sense if the plane truly is a
refrozen Surface likely making it two
billion years younger than the rest of
Kalisto the Rings are likely fractures
in the crust a concentric failure in the
brittle shell of the Moon interestingly
though within the Rings these bright
knobs are still still visible so what
are the
knobs well they are believed to be the
degraded remains of the millions of
crater rims from kalisto's past we don't
know exactly why they have degraded so
much over time but perhaps it's due to
micrometeor impacts or simply the ice is
slowly sublimating over time they are
brighter than the lower Plains because
the Rocky dead brief from the meteors
and micro meteors will have fallen down
the knobs over time leaving the Pure Ice
exposed at the top smaller impact
crators are also fascinating due to
their uniqueness most impact craters are
shallower on Kalisto compared to our
moon for instance the Luen impact
structure it's well over 100 km wide
however it's only 600 M deep this could
be because the impactor was breaking
apart before it impacted causing more of
a spread out shotgun effect on the
surface or it could be that the surface
has since leveled off from other larger
nearby impacts that have occurred later
on this crater is believed to be over a
billion years old at least yet you can
still clearly see the ejector that is
streamed away from the impact clear
evidence of how unchanging this
remarkable moon
is with some craters like har crater
there is even a large Dome found in the
Middle with typical large impacts on
other worlds you will see a few
concentric rings and a bed peak in the
center this is very much the case on our
moon however Kalisto has some remarkable
examples of large craters where just the
opposite happens look at Tinder here
instead of a peak there is actually a
pit in the center why does Kalisto have
such unique crators it could be due to
the fact that kalisto's crust is not
just brittle but pretty thin too with
either soft ice or a salty ocean
underneath estimates put the crust at 80
to 150 km thick the Galileo space probe
which spent several years around Jupiter
spent a significant chunk of its time
aptly studying the Galilean moons
Galileo found that Jupiter's magnetic
field could not penetrate through
Kalisto implying there is a highly
conductive layer under the surface at
least 10 km thick this couldn't have
happened in ice or silicat unless the
ice layer is at least partially molten
or very very large temperature gradients
can be maintained below the ice to
create a conductive effect data also
suggests that Kalisto has a small silic
core at its center with a radius of
about 600 km which begs the question can
Kalisto be conducive to life like other
icy worlds with water mantel under their
surfaces well Life as we know it
requires liquid water and energy to
exist Kalisto might have an ocean of
liquid water under its surface but being
about 800 million km away from the Sun
it barely receives any heat from our
Star and the absence of tidal forces
doesn't help either leaving radioactive
elements the only source of heat to warm
this subsurface ocean if it exists and
unfortunately even visiting Kalisto
won't prove anything moons like Europa
and Enceladus have vents ejecting water
directly from their subsurface oceans
meaning we can investigate habitability
prospects without ever going into the
oceans themselves no such vents exist on
Kalisto so scientists would have to
penetrate the crust in order to find out
all these things combined mean that
unfortunately scientists think that the
environmental conditions necessary for
Life appear to be less favorable on
Kalisto than on any other icy worlds
nevertheless Kalisto shouldn't be
ignored if we ever go to explore the
outer solar system kalista would make a
perfect base you see orbiting at a
distance of 1.9 million km from Jupiter
means that Kalisto is located Beyond
Jupiter's main radiation belt making its
environment thousands of times more
conducive to human exploration than its
inner
moons Kalisto also has a lot of water
ice that can be used for propellent
production and of course is the staple
to keep humans alive separating the
hydrogen from oxygen also leaves oxygen
for
breathing C geological stability would
make for building structures on the
surface relatively WorryFree and the
lack of huge mountains or deep trenches
means it's faster easier and more
efficient to travel over from Kalisto we
could better explore the inner Jovian
system from a safe distance or use it as
a way station for heading further into
the outer solar system lifting off from
Kalisto would be ideal thanks to its low
gravity and you could get a gravity
assist from a close flight by of Jupiter
it's true that this is a futuristic
Prospect although if we ever do become a
space fairing species this is a distinct
possibility now while Galileo did an
admirable job studying Kalisto during
its few flybys there is still a lot of
information gaps that need to be filled
with any luck we'll get that from the
European space agency's Jupiter iy moon
Explorer due to launch in 2022 which
will reach the Jovian system by 2030 and
will explore Jupiter and three of its
largest moons ganm Kalisto and Europa
Issa has planned several close flybys of
Kalisto during this Mission this Mission
might provide more insight into
questions like does it have a subsurface
ocean and if so does it or can it
sustain life beyond that there's also
the questions we haven't thought to ask
yet who knows what more we will still
discover about this incredible Moon
so there we have it almost everything
you could want to know about the
Galilean moons of
Jupiter on the 5th of July 2016 Juno
successfully arrived at Jupiter and
inserted itself into a polar orbit this
means Juno has spent the last year
Gathering data around the biggest planet
in our solar system so what has it
actually seen was it worth all the fuss
of getting this orbitor to Jupiter in
the first place well take a look at a
few of these breathtaking
pictures and then you tell
[Music]
me of course Juno isn't just an
expensive camera and has been performing
several different scientific experiments
as well and the results have completely
changed the way we understand the solar
system and
Jupiter so what has Juno been doing it's
in a highly p perpendicular orbit which
brushes over the planet at its closest
approach only 4,200 km above Jupiter's
atmosphere the furthest point takes Juno
out over 8.1 million km each orbit takes
53 days to complete and it will complete
12 orbits by the end of its mission in
July
2018 at the time of making this video
Juno has completed Parov 6 or its sixth
closest approach so about halfway
through this Mission as Juno is in good
health it could be that his mission is
extended Beyond
2018 one of the reasons Juno approaches
so close to the planet is to avoid
Jupiter's powerful radiation belt there
is a gap where the planet ends and the
radiation belt starts and Juno exploits
that there was some concern that Juno
would still get a huge dose of radiation
from the parts of the radiation belt it
does hit but the radiation was actually
10 times lower than expected in these
parts great for the health of the
probe do you remember the previous
Jupiter probe Galileo Galileo faced a
number of setbacks due to the damage
received by Jupiter's radiation as its
orbit went right through the middle of
the radiation belt so Mission planners
were Keen to avoid a repeat of that as
much as
possible another advantage of the tiny
distance from Juno to Jupiter at its
closest approach is that we've been able
to see Jupiter in un unprecedented
detail the first images of Jupiter's
poles in particular took people's breath
away some even say that scientists would
not even even recognize the planet from
these
images just no one expected what they
saw what you're looking at here of many
Cyclones around the South Pole what is
remarkable is that the planet looks so
different from what we're used to seeing
on Jupiter namely large
bands however the contrast of the image
has been increased to see details the
natural eye would see something more
like
this this image is also a mosaic of
several images in order to show daytime
on all sides of the planet the North
Pole isn't quite so clear as it's in
Winter and some parts of the pole are in
constant
night Juno also has the capability to
peer deep into Jupiter's atmosphere
using a micro wave radiometer which was
designed specifically for this
spacecraft using it scientists were able
to see the amount of ammonia in the
atmosphere what they didn't expect to
see was this band of ammonia around the
equator ammonia being Orange in this
image the pillar drops down from the
cloud tops over 350 km the limit of what
the MWR can see scientists are very
puzzled by this as they expected to see
an even distribution of ammonia
throughout the planet they thought the
gases in the atmosphere would just mix
up or at least stick to the band pattern
on the planet but these results are far
from then this shows how variable the
planet is under the top layer of
clouds previously scientists had
predicted that Jupiter had a solid core
but using the gravity science instrument
it seems a lot hazier or fuzzier than
they would have anticipated this could
imply the core is not solid it's
dissolved or it doesn't exist at all and
it may be a while yet until we
understand the truth about this point
when all the microwave radio wave and
magnetic field data have been combined
to give a more complete picture speaking
of the magnetic field the results from
this also came as a surprise to
scientists in some places the magnetic
field was stronger than they expected
and in others they were weaker these
patches you see also imply the magnetic
field is being generated above the core
of the planet as it's quite irregular
perhaps originating in the metallic
hydrogen
layer the magnetic field as we know
creates Aurora and Juno has an infrared
Aurora mappa giving us a view of
Jupiter's Aurora like we've never seen
before the central band in this
animation is the main Aurora and this
moving point to the left is caused by
the closest of Jupiter's Galilean moons
IO the tale of the point point is the
remnant of I's orbital motion the whites
and greens from this image are iron
strike in Jupiter's ionosphere from
space and the Reds could be ions coming
from the planet itself if this is the
case this has never been observed
before most of the data collecting takes
place but only a few hours per orbit as
Juno whizzes by the planet all the
instruments collect as much as possible
during this time including the camera
this REM
video is a time lapse of Jupiter
approaching the Northern Hemisphere and
leaving again as it looks towards the
Southern
Hemisphere and this image is a
collection of all the frames that were
used in the video as Juno approaches the
planet you can see the storms around the
North Pole and gradually The View shifts
to the mid latitudes zooming in on some
of these shots we can see the classic
Swirls and patterns we expect on Jupiter
but having a really close look we can
see these white specks these specks are
actually water or ammonia ice clouds as
can be seen by the Shadows they
create they are higher in the atmosphere
than the rest of the cloud layer and
although they look small they actually
over 50 km
wide Jupiter is just really big so it
looks
small now you've noticed them once
you'll start to see them
everywhere due to the freezing cold
temperatures at this altitude where the
clouds are and because they are made of
water ice it could very well be snowing
on Jupiter remarkably we are still
learning so much about our giant
neighbor you might have thought that
because it's the closest and biggest gas
giant we would have a pretty good
understanding of his mechanics it seems
with the arrival of Juno however we
still have a lot to learn and there's
probably questions we don't know yet let
alone
answers I don't I know where the time
has gone but it's now been 3 years since
Juno arrived at Jupiter during this time
it has been collecting valuable and
insightful data about the largest of our
neighbor planets it has recently
completed parove 21 or its 21st polar
orbit out of a total of 35 planned
orbits which means we are now well past
the halfway point of this
Mission some of you veterans to this
channel will remember the video I made
about Juno at its one-year mark but what
has it discovered since then and has it
disproved some of the assumptions we had
about Jupiter from before it
arrived I'm Alex molan and you're
watching astram and together we will go
through everything Juno has discovered
and seen around Jupiter so
[Music]
far there was some skepticism about
whether Juno would last this long due to
the intense radiation around the planet
but Juno is currently in good health
it's po orbit takes it very close to the
planet only 4,000 km above its
atmosphere meaning it avoids most but
not all of Jupiter's plasma Taurus or
this region of extremely energized
particles particles which have been
trapped in place by Jupiter's powerful
magnetic
field but thankfully Juno quickly
discovered that the radiation where it
orbits was a lot weaker than initially
expected this means that even the camera
is still up AAL which was one of the
first instruments expected to
go Juno completely surprised scientists
though by discovering another small and
less powerful radiation belt right above
the equator which hugs the planet
tightly so far the mechanisms behind
this radiation belt are
unknown however although the radiation
exposure hasn't been as bad as
scientists expected due to the nature of
Juno's orbit every passing parove takes
it more more and more into the main
radiation belt meaning Juno certainly
can't last forever emper of 35 is
currently when Mission controllers
believe the mission will be forced to
end whereupon they will crash Juno into
Jupiter to avoid any future collisions
with
[Music]
Europa the charge particles in the
plasma Taurus come particularly from the
volcanic activity of Jupiter's largest
moon IO which blasts particles into
orbit around Jupiter
just to give you an idea of how
volcanically active IO is this was New
Horizon's view of IO as it passed by
Jupiter on its way to Pluto the tashar
volcano in full
eruption Juno has also had a look at IO
in the infrared the hot spots indicating
where volcanic activity is
occurring IO ejects one ton of particles
into orbit around Jupiter per
second as IO travels through the plasma
Taurus and interacts with Jupiter's
magnetosphere this causes a flux tube to
exist between the planet and the moon a
flux tube being an electric current that
travels along a cylindrical tube of
magnetic field lines it is very powerful
it can develop 400,000 volts and 1
million to 5 million amps of current
Juno was able to get very accurate
readings of the flux tube during its
12th orbit as it passed directly through
it no this didn't fry the spacecraft as
the flux tube has a large diameter and
so it isn't concentrated enough to do
damage to the craft also Juno was in and
out in a matter of
seconds now Juno is a massive spacecraft
20 m in diameter and it really has to be
as it is a solar powered spacecraft and
only gets 4% of the sun it would do
around Earth this means even though
these panels are huge it can only
generate just above 400
watts but you'll also notice that this
design paired with the fact that Juno
rotates makes it look a little like a
fidget
spinner this isn't just to make a pretty
spinning spacecraft Juno was
specifically designed to detect various
fields and particles around Jupiter and
having a spacecraft with a large
spinning radius helps with
that this is particularly evident with
this instrument here the magnetometer
found at the end of one of the solar
panels tasked with mapping out Jupiter's
magnetic field through Juno's data we
now have a highly detailed map of
Jupiter's magnetic field which is only
getting more accurate with every passing
orbit as expected Juno confirmed that
Jupiter has a dipole likee magnetic
field although it is not very aligned
with the rotational
axis what was very interesting though is
that scientists discovered something
called the great blue spot a region on
Jupiter where the magnetic field is very
concentrated comparing Juno's magnetic
field data with previous Jupiter
missions like pioneer Voyager and
Galileo has also revealed a first for
the solar system Jupiter's magnetic
field structure has been found to change
very gradually over time which is called
secular
variation interestingly this was most
apparent around Jupiter's Great Blue
Spot this variation is thought to be
driven by a region right at the base of
Jupiter's atmosphere which we'll get to
in a
bit a combination of the powerful
magnetic field and the charged particles
in the plasma Taurus means that Jupiter
has the brightest Aurora in the solar
system with a radiant power of 100
terawatts like Earth Aurora appear as
bands around the North and South Poles
but unlike Earth these Aurora are mainly
visible in the ultraviolet and are
mainly produced from alternating
currents not direct
currents when Juno measured the power
generated from the direct currents in
Jupiter's magnetosphere it was nowhere
near enough to account for the
brightness of the Aurora leading
scientists to speculate that the
remainder of the power is coming from
alternating currents at this time it is
believed that these alternating currents
are produced because of the turbulence
in the magnetic field especially at the
North Pole the magnetic field lines are
much more complex which interferes with
a direct flow of currents this is
evident When comparing the North and
South Pole Aurora at the North the
Aurora is much more dispersed looking
more like filaments and
flares whereas at the South Pole where
the magnetic field lines are smoother
the Aurora seems to be more structured
and
round what you will also notice is this
bright spot and tail in the Aurora this
is visibly where the iux tube meets the
planet
what is less apparent though are these
other spots these are from the other
large moons in the Jovian system Europa
and
ganam so while not as powerful as io's
flux tube these other moons have their
own flux tubes connecting them to the
Planet
Too the magnetic field of Jupiter brings
us nicely to one of the main science
goals of Juno to figure out the interior
of Jupiter since Juno arrived previous
theories have had to be completely
thrown out the window by the data it is
collected previously it was thought that
there was a solid core and then a sharp
cuto line between the core and the next
layer the metallic hydrogen layer the
cloud layer was then only thought to be
a few hundred km deep at most but based
on the Juno data the atmosphere of
Jupiter extends to 3,000 km down and
beneath this is an ocean of metallic
hydrogen going all the way down to the
center and even if there is a core it is
very fuzzy potentially mixing up with
the metallic hydrogen layer so actually
to call Jupiter a gas giant is a bit
disingenuous as 80 to 90% of its radius
is believed to be a liquid now or
technically an electrically conduc in
plasma perhaps similar in appearance to
liquid
mercury here the pressure is so great
that the hydrogen doesn't retain its
molecular structure with two combined
protons and electrons and instead they
separate at meaning positive and
negative charges can move about becoming
an electrically conducting substance we
say believe as we haven't been able to
recreate metallic hydrogen in lab
conditions yet the pressure needed is
millions of times greater than the
atmospheric pressure of Earth although
we assume this must be the case due to
Jupiter's powerful magnetic field to
create a magnetic field of this strength
the Dynamo must originate in an
electrically conducting substance a
can't be a denser metal like iron in
Earth's core because Jupiter doesn't
have the density for that in fact based
on its density we know that it must be
made primarily of hydrogen and smaller
amounts of helium very similar in
composition to the
sun another factor for the strength of
the magnetic field is due to the rapid
rotation of Jupiter one day on Jupiter
only lasts about 10 hours various forces
from this stir the liquid up which
generates the Dynamo
it is the rotation of the magnetic field
from which we can measure a day on
Jupiter as simply viewing Jupiter's
visible bands couldn't give you a
definitive result and this is why you'll
notice these bands look very peculiar
moving in opposite directions from each
other at different
speeds but this isn't so unusual if you
consider the invisible jet streams on
Earth what is striking though is the
colors and turbulence found in these B
bands so let's try and understand what's
going on from examining these Juno
images the cloud layer you are seeing
here is the ammonia Cloud layer some are
white these represent fresh clouds
likely only recently pulled up from the
deeper parts of the atmosphere on the
other hand while the red colors you see
are also ammonia clouds these clouds
have interacted with UV light from the
sun think of it like a photochemical
smog the reddish smog you see in summer
over large cities the coloring substance
isn't exactly known but simply put the
longer it is exposed to the Sun the
redder it
gets interestingly though comparing
these bands to what you see at the poles
you'll notice it is a lot Bluer here
this could be because UV light doesn't
reach here as easily compared to the
equator looking closely you'll also
notice what is known as popup clouds
initially these were thought to be maybe
water ice clouds but they could be
ammonia clouds too they are potentially
the precursors for thunderstorms on
Jupiter the radio wave instrument on
board Juno does detect lightning on
Jupiter however these storms are
interestingly more localized towards the
poles than at the equator and more
towards the North Pole than the South
Pole the cause for this is
unknown looking closely at Jupiter you'd
be hard pressed not to notice the
stunning vort vortexes and storms across
the
planet Juno has had the opportunity to
orbit directly over the great red spot
where it discovered something very
interesting it was known that the Great
Red Spot Rises high above the cloud deck
but what scientists didn't expect is How
Deeply it penetrates Jupiter's
atmosphere the instrument on board Juno
designed to peer into the atmosphere has
a range of 350 km and it seems the Great
Red Spot extends down even further than
that also interesting is that the spot
is cooler than the surrounding area up
until a depth of 80 km and beyond that
it actually gets warmer than the
surrounding area this heat perhaps
driving the
storm it has been theorized that the
Great Red Spot is a permanent feature on
Jupiter but we've only had about 400
years to observe it so far a mere blink
in astronomical time scales looking over
the poles other possible permanent
features have been observed
in contrast to Saturn which has a
hexagon on one pole and a single Vortex
on the other Jupiter has five vortexes
around the South Pole and eight around
the north it's hard to say exactly how
permanent these storms are as Juno has
only been there for 3 years and Juno was
the first time we have really been able
to have a good look at Jupiter's poles
but they have been reasonably constant
throughout that
time under the ammonia Cloud layer it's
thought to be a water ice Cloud layer
although this is not been confirmed as
this layer hasn't actually been seen yet
this is one of the science goals of Juno
though and it has several microwave
detectors to try and find this elusive
substance Jupiter generates heat from
within which can be seen through an
infrared camera the densest parts of the
cloud layer blocking some of the heat
from being visible similarly Jupiter
also emits microwaves
which hypothesized water clouds would
absorb so in theory Juno should be able
to detect where the water is present in
Jupiter's atmosphere by searching for
where Jupiter's microwaves aren't
visible although this data has either
not been released or nothing has been
found
yet all that being said Juno still has a
while to go with this Mission and no
doubt the data it collects will be
examined for years to come our
understanding of Jupiter is gradually
increasing and with this knowledge comes
a better understanding of how our solar
system formed and also that of other
solar systems with Jupiter sized
worlds and who knows maybe Jupiter will
surprise us a few times more
yet it's been 6 years since Juno began
orbiting Jupiter during that time the
probe has been busy gathering incredible
images and data from the gasas GI giant
Veterans of this channel may remember
videos I released on the mission's first
and third anniversaries but a lot has
happened since then in 2021 Juno began
its extended Mission beyond the
initially planned 37 orbits to include
flybys of Jupiter's icy inner moons
gamed Europa and eventually IO it's been
over two decade since Galileo visited
these moons and by studying changes in
them NASA hopes to understand what might
be going on beneath their icy surfaces
and without letting the cat out of the
bag too soon that appears to be a
lot also thanks to the probe's powerful
cameras Juno Cam and its Stellar
reference unit navigation camera Juno is
taking some of the very best images
we've had of these icy moons so with the
long running missions end on the horizon
as NASA plans to decommission the probe
in September 2025
now seems like a good time to ask what
has Juno
seen I'm Alex molan and you're watching
astram join me today as we view the
stunning highlights of Juno's extended
Mission and unpack the surprising
discoveries that are already changing
our understanding of the Jovian
system let's start with a quick recap
Juno launched from Cape Canaveral
Florida in August 2011 after traveling
for 5 years and two .8 billion kilm the
space probe began orbiting Jupiter on
July 5th
2016 after completing most of its
primary objectives NASA extended Juno's
Mission and set its sights on some of
Jupiter's largest moons in total the
extended Mission will add 42 orbits or
parage joves by
2025 at the end of which NASA will
deorbit the probe by burning it up in
Jupiter's atmosphere to avoid
potentially contam ating those moons
this procedure is in accordance with
NASA's planetary protection guidelines
but it's of special importance in Juno's
case scientists have long wondered
whether there could be life on Jupiter's
inner moons and NASA doesn't want to
muddy up any future discoveries that
could be made there so on the 7th of
June 2021 Juno performed its close
flybys of ganam using a gravity assist
to bring his orbital period from 53 days
down to 43 days Juno had already
performed a distant flyby of ganam in
2019 when it reached a proximity of
97,000 KM but this one brought the probe
within just 1,000 km of the moon's
surface in this Photograph captured by
Juno cam you can see nearly half of
ganim's total surface in breathtaking
detail for reference the resolution is
about 1 km per pixel I love the crisp
rendering of ganim's unique structural
features you can practically feel its
texture with your
fingertips notice how the icy surface is
littered with craters light and dark
patches and long
striations the darker areas show older
terrain which is heavily crated whereas
the lighter areas are comparatively
younger and less crated but what about
those long
striations we know based on previous
data that contains at least one vast
salty subsurface ocean beneath its icy
outer layer which some speculate could
be suitable for life scientists think
that these long structural features
might reveal faults produced by tectonic
movements generated by heat from the
moon's iron nickel core but this is a
subject of ongoing
research this image taken from the same
flyby on the 7th of June shows ganim's
Tross crater in Greater detail
the reason it appears so bright is that
it's covered in ice here is another
image from the 7th of June which I find
remarkable it's a photograph of ganim's
dark side and it was taken by Juno's
Stellar reference unit navigation camera
the Stellar reference unit was designed
to keep Juno on course using Starlite
which makes it ideal for photographing
low light conditions for scale the
resolution is between 600 and 900 m per
pixel
again notice the moon's long striations
and craters some of which are stacked on
top of each other I've seen a lot of
photos of ganam many of which I've
covered previously but I'm flawed by the
level of detail Juno was able to capture
in such low light
conditions interestingly one of the most
surprising discoveries from the mission
came not from the Orbiter itself but
from Hubble yes that Hubble allow me to
explain you see to support Juno's
exploration of the Jovian moons NASA
asked hble to monitor ganim's
ultraviolet
signals ganam has an atmosphere albeit a
very thin one and one of NASA's goals
was to find traces of oxygen they long
suspected was hiding there nearly
everyone expected to find plenty of
oxygen based on previous analysis of the
moon's ultraviolet emissions but much to
our surprise ganim's atmosphere had very
little oxy o in it what they found
instead was a whole lot of water vapor
this discovery led to a significant
revision of our model of ganam
atmosphere and could suggest that water
vapor might even be present in the
atmospheres of icy bodies throughout the
solar
system after visiting ganam Juno made
its flyby of Europa on the 29th of
September 2022 which gave the probe a
gravity assist that shortened its orbit
to 38 days here is a dramatic image from
the flyby taken at a distance of 351
km it shows a portion of Europa just
north of the equator what I find
extraordinary here is the day night
boundary known as the Terminator the
Deep Shadows really accentuate The
Ridges troughs and craters that riddle
the moon's surface showing it in almost
threedimensional
relief scientists think that Europa like
anamed Harbors a vast ocean beneath its
ice exterior but new findings suggest
there could be a lot more going on than
the simple ocean crust model would have
you believe what do I mean by this well
hold that thought as we study the next
image this Photograph was taken by
Juno's Stellar reference unit camera and
shows a zoomed in portion of europa's
surface it was taken during the moon's
night from a distance of 412 km with a
resolution of 256 m per pixel this is
the highest resolution image that Juno
took of Europa at a glance your first
thought might be what am I looking at
well what you're seeing is a heavily
fractured region of europa's surface
crisscrossed with grooves and Ice ridges
and that oddly shaped dark patch just to
the right of Center could yield
important Clues as to what's behind this
geological
complexity scientists believe this
darkened area shows an eruption
occurring below the surface ice the
thing is europa's icy shell is over 10
km thick imagine the pressure needed to
penetrate so much
ice however a new paper published by
American Astronomical Society proposes a
groundbreaking new Theory pardon the pun
with a different
explanation according to the paper's
authors europa's cryovolcanic activity
shows evidence of brine reservoirs
trapped within the icy outer crust
this would mean that far above the Moon
subsurface ocean there could be Lakes of
high salinity brine that slushes about
expanding the surrounding ice like a
balloon and bursting through on occasion
it's a compelling Theory but to prove it
we may have to wait for the European
space agency's Clipper Mission which
will reach Europa sometime in
2030 I know that's 8 years away but it's
not too early to mark your
calendars let's head back to Jupiter one
more time you see while Juno was paying
visits to gamed and Europa it also
solved a big mystery one that goes back
more than 40 years when the Voyager
Mission first visited Jupiter in
1979 the probes detected mysterious
flashes in Jupiter's atmosphere
scientists assumed that these were
lightning flashes similar to those we
see on Earth meaning water would have to
be present in all its states solid
liquid and gas given what we know of
Jupiter's atmosphere this would put the
storms at least 45 km below the visible
Cloud tops however Juno disproved this
Theory and the truth is stranger than we
imagined Juno Stella reference unit
camera saw something weird nighttime
flashes at a far higher altitude than we
thought possible given the incredibly
cold temperatures at this altitude
reaching below - 88° c science deduced
that the storms were made of ammonia
water-based clouds a phenomenon that
doesn't exist here on Earth in these
strange and violent thunderstorms the
ammonia acts like an antifreeze forming
a solution of two parts water one part
ammonia that remains liquid despite
unimaginably cold conditions and
apparently as these thunderstorms
produce powerful lightning strikes they
are raining down massive haill made of
water ammonia slush and unusual
precipitation that scientists are
calling mush
balls Jupiter is a strange planet and
the more we learn the stranger it
gets so there we have it some of the
best highlights of the trailblazing Juno
Mission since we last checked in the
next stop for Juno will be IO sometime
in 2023 and personally I can't wait to
see what's in store Juno has vastly
exceeded my expectations every step of
the way and if ganam and europ are any
indication our understanding of IO is
about to get a whole lot more
interesting thanks for watching making
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