[Music]
while the planets get a lot of the
attention in school and by space
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 is 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 System's
very
beginning I'm Alex molan and you're
watching astram and in this video we
will go through these 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
moons I 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
tital Bulge on iO is thought to be up to
100 m this effect is similar to what we
see on Earth with the ocean's Tides
being caused by the moon although on
Earth the effect is much more minimal
the tides only usually shif in about 2 m
from high to
low iio is getting 300% more tidal for
for 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 eccentric
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 I 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
silicat 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 1970s 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 1 and two missions in
1979 Voyager 1 flew by at a distance of
only 20,000 km and was able to take some
impressive close-ups of io's 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 kilometers wide and what
looked 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 1 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
atmosphere 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 volcanos 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 malfunction
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 planes
are composed 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 and galile 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 t 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 Laval 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 tasa 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 reaching 18 km
tall these mountains tend 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 fults 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 EXT stand
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 magnetic field
the plasma Taurus rotates a lot faster
than io's orbit at 70 km a second
compared to io's 17 km a second orbital
velocity IO orbits right through the
middle of it with the particles from the
Taurus bombarding the part 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 neutral 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
Mysteries this is the first ever
close-up 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 the 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 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 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
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 unlike on Earth the oxygen on
Europa is formed by radiolysis or in
other words the process of radiation
bombarding the water ice surface
separating the H2O into oxygen and
hydrogen hydrogen escapes europa's
gravity altogether 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 dispersed neutral Cloud which
follows the orbit of Europa around
Jupiter in 2012 the Hubble Space
Telescope discovered plumes of water
vapor 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 Galileo 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 mantle
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 conductive 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 5 times further away
than the earth that makes the sunlight
about 25 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 - 160° c at
the equator and - 220° c at the poles
keeping europa's icy crust as hard as
Granite however tidal pressures 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 of
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 contact with
europa's silicate Rocky mantle this
makes europa's ocean a suitable
environment for Life as we know it to
exist we believe that 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 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 Moon's
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 plumes and
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
everything you could want to know about
the fascinating world of
Europa
gamed 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 intriguing 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 kilm 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 for 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 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 gamed has an
atmosphere that contains oxygen now you
might be wondering with all this water
and an oxygen atmosphere is it possible
that life exists on ganam well 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 ganam ice and water exists
something else truly surprising
something that scientists do not have an
explan ation 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 gamed 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's 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 molten
convection currents within it move
electrons which in turn produces the
magnetic field that surrounds us here
however this shouldn't be happening on
ganam 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 electrons 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 gamed orbits
around Jupiter roughly once every 7 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 attack 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 ganam has
formed an orbital resonance with two of
its fellow Galilea 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
pulled 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
and thousands of kilometers long truly
an impressive sight but again scientists
are not sure how these ridges formed one
explanation is that tidal forces
stretched out the surface of the Moon in
an unstable period of ganim's ancient
history perhaps this same tidal Force
could have also warmed ganim's core and
preserved its magnetic field whatever
it's 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
gamed 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
ing 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 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 sulation
of carbon dioxide surface IES 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 its 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 ples
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 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 crators 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 impct Factor
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 mled
appearance there seems to be a big
difference in contrast between the
bright knobs and the darker plane these
regions are a lot less created than the
rest of kalisto's surface which would
make sense if the plane truly is a
refrozen Surface likely making it 2
billion years younger than the rest of
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 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 or simply the ice
is slowly sublimating over time they are
brighter than the lower Plaines because
the rocky debris from the meteors and
microm meteors will have fallen down the
knobs over time leaving the Pure Ice
exposed at the top smaller impact
craters 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 shot andun 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 raised 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
kisto have such unique creators 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 large temperature gradients can
be maintained below the ice to create a
conductive effect data also suggests
that Kalisto has a small silica 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 mantles 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
water ice that can be used for
propellant production and of course is
the staple to keep humans alive
separating the hydrogen from oxygen also
leaves oxygen for
breathing kisto geological stability
would make for building structures on
the surface relatively worry-free 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 flyby
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
his 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 icy 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 gamed 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 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 in the vast expanse of our solar
system orbiting the ringed giant Saturn
lies a world of ice and
mystery this is Ria Saturn's second
largest moon although you're more likely
to have heard of its largest sibling
Titan Ria is a fascinating place in its
own right and harbers many secrets and
wonders ice Cliffs hundreds of meters
high an internal structure that defies
scientific models and the enigmatic
discovery that lingers around this Moon
that's equally as strange as the thing
we didn't
find it's time for this lesson no moon
to step out from its larger sibling
Shadow let's learn all there is to know
about
[Music]
Ria I'm Alex Mulan and you're watching
astram join me today on a voyage of
Discovery to the saturnian system and
the moon rear to see what scientists
have discovered there and to witness its
beauty for ourselves
Ria was discovered on the 23rd of
December
1672 by Giovani Domenico Cassini the
Italian astronomer who made numerous
contributions to our understanding of
Satan and its moons named after the
Titan goddess Ria in Greek mythology
this moon has been a subject of
Fascination for astronomers and
planetary scientists for
centuries let's start with the basics
is the second largest moon of Saturn
after the mammoth Titan with a diameter
of
1,528 kilomet it's roughly half the size
of our own Moon if we were to place rear
next to Earth it would stretch from
London to
Warsaw rear orbits Saturn at a distance
of about 527,000 km completing one orbit
every 4.5 Earth days it's locked in a
synchronous rotation with Saturn meaning
the same side always faces the planet a
common feature among large moons in our
solar
system the surface of Ria is one of the
most reflective in our solar system with
an albo of
0.7 this means it reflects 70% of the
sunlight that hits it appearing bright
white against the backdrop of space this
high reflectivity is due to its
composition rear surface is primarily
made of Water Ice
but this doesn't make it a featureless
ice sheet far from it the Moon is
heavily crated telling a story of
ancient impacts and a long violent
history the largest of these craters
named mam maldi spans an impressive 480
km in diameter about the distance from
haris to Amsterdam these craters aren't
just scars on rear surface they are
windows into the moon's past and
composition obser ations have shown that
the bottoms of some craters appear
darker than the surrounding terrain this
could indicate that impacts have
excavated material from beneath re's
bright surface possibly exposing darker
amorphous water ice and impact
melt in this photo you can see a crater
in the southern hemisphere of Ria
surrounded by bright
ejector but one of the most intriguing
features of Ria is its system of bright
wispy streaks that crisscross its
surface these were first observed in
detail by the Voyager space probes in
the early 80s but their true nature
wasn't understood until the Cassini
Mission provided high resolution images
decades later initially thought to be
deposits of frost or ice these wisps
were revealed to be ice Cliffs some
hundreds of meters high they are likely
the result of tectonic activity in Ria's
past where the icy crust fractured and
some sections were thrust upward these
features give us clues about the moon's
geological history and the processes
that have shaped its surface over
billions of
years but Ria's Mysteries don't end at
its surface in 2010 data from the
Cassini spacecraft led to a surprising
announcement Ria appeared to have a
tenuous atmosphere or exosphere a small
amount of gas around Ria is expected but
it was unexpected that there is enough
to be measurable the detected atmosphere
consisted primarily of oxygen and carbon
dioxide with the oxygen being about 5
trillion times less dense than Earth's
atmosphere at sea level while incredibly
thin the mere presence of this
atmosphere raised intriguing questions
about its origin and
sustainability one Theory suggests that
the oxygen is produced by the
decomposition of water ice on R surface
when it's struck by ions from Saturn's
magnetosphere
the carbon dioxide on the other hand is
thought to be the result of organic
molecules on the surface being oxidized
by the oxygen in the
exosphere this discovery made Ria the
first moon known to have an oxygen
atmosphere other than Jupiter's moons
ganam and Europa it also opened up new
avenues for Research into the complex
interactions between Saturn's moons and
the planet's powerful magnetosphere
Ria's exterior is fascinating but what
about its interior let's dive deeper
literally while we can't directly
observe what's beneath the Ria's icy
surface scientists have used various
methods to infer its internal structure
based on Ria's average density of 1.23 6
G per cubic cm which is only slightly
higher than that of water we can deduce
that Ria is composed primarily of Water
Ice about
75% and a smaller fraction of rocks the
remaining
25% rear has often been described as a
frozen dirty snowball due to this
structure this puts rear in STK contrast
to moons like our own Moon which are
primarily Rocky bodies when Cassini
visited Ria the probes instruments also
provided valuable data about Ria's
composition spectroscopic observations
confirm that water ice is the dominant
component of rear surface but they also
detected the presence of other materials
one surprising discovery was the
detection of carbon dioxide trapped in
the surface
ice this finding suggests that Ria's ice
isn't pure water but contains other
compounds possibly including complex
organic molecules due to its higher
moment of inertia most scientists
believe that Ria is not differentiated
into layers instead it is thought to be
a homogeneous mix throughout out with
the exception of its core some
scientists challenged this model though
in 2006 a paper was released in the
journal Icarus that suggested that Ria
might have a layer of liquid water under
its surface a subsurface ocean while
this idea is still highly speculative
and not as well supported as the
subsurface oceans on moons like Europa
or Enceladus it's an intriguing
possibility that future missions might
investigate the presence of such an
ocean would have significant
implications for Ria's potential
habitability and of the conditions
necessary for liquid water in the outer
solar system Ria's interior contains
Mysteries but one of the puzzling
features of Ria is its shape while many
large moons and planets tend towards a
perfect sphere due to their own gravity
Ria is noticeably
nonspherical it's slightly flattened at
the poles and B Es at the equator a
shape we call a traal ellipsoid what's
strange is that rear shape doesn't quite
match what we'd expect based on its
rotation rate this discrepancy has led
scientists to propose that Ria might
have a nonuniform internal structure
with denser material concentrated away
from its
center now let's talk about one of the
most exciting moments in Ria's recent
history the Cassini missions close
flybys the Cassini spacecraft a joint
project of NASA Issa and the Italian
space agency spent over a decade
studying the saturnian system including
several close encounters with Ria the
closest of these flybys occurred on the
11th of January 2011 with Cassini
passing a mere 76 km above Ria's surface
the last close flyby was on the 9th of
March 2013 when Cassini passed just 997
km above RAR surface this close approach
allowed the spacecraft to capture
incredibly detailed images of Ria's
created terrain and gather valuable data
about the moon's composition and
determine it does not have an internal
magnetic field these flybys provided us
with our best look yet at Ria's surface
features they imaged a landscape
dominated by two types of terrain
heavily created regions and younger
smoother planes first shown in earlier
Voyager missions the heavily crated
areas we mentioned earlier are thought
to be extremely old possibly dating back
to the early days of the solar system
these ancient surfaces provide a record
of the intense bombardment that occurred
in the Solar System's youth the smoother
planes on the other hand are likely the
result of a resurfacing event such as
from Material ejected from large impact
events
this material would have fallen back to
the surface filling in Old the craters
and creating smoother
regions but perhaps one of the most
intriguing results from the Cassini
mission was what it didn't find prior to
cassini's arrival some scientists had
proposed that Ria might have a system of
rings this idea was based on unusual
measurements of electron densities
around Ria made by Cassini in
2005 however despite careful searches
during its flyby Cassini found no
evidence of rings around
rear this non detection doesn't
completely rule out the possibility of
some kind of Dey disc around rear but it
does make it much less
likely another intriguing aspect of rear
is its place in Saturn's complex system
of moons rear orbit saton in what is
known as the e-ring a diffused ring of
ice particles thought to be supplied by
the cryo volcanic eruptions from
Enceladus while Ria itself doesn't seem
to be geologically active like Enceladus
its position in this ring means it's
constantly interacting with these ice
particles although Ria is in the
extremities of the e-ring Beyond where
it is dense over time this interaction
could affect rear surface properties and
contribute to the moon's bright
appearance as we reflect on what we've
learned about rear it's clear that this
Moon Often overshadowed by its more
famous siblings is a fascinating World
in its own right from its heavily
created hemisphere to its relatively
smooth side from its tenuous atmosphere
to its place in Saturn's complex system
of moons Ria continues to Intrigue
scientists and Spark our
imagination but our exploration of Ria
is far from over many questions remain
unanswered what is the exact nature of
its interior structure how has it
evolved over the billions of years since
its formation could it Harbor simple
forms of life in a hypothetical
subsurface ocean these questions and
more await future missions to the
saturnian system while there are
currently no planned missions
specifically targeting Ria the Moon is
likely to be observed by any future
spacecraft sent to study Saturn and its
moons
[Music]
as we conclude our journey to rear let's
take a moment to appreciate the
diversity of worlds in our solar system
from the scorching surface of Venus to
the icy Plains of Pluto from the
Towering volcanoes of Mars to the
potential subsurface oceans of icy moons
like Enceladus our Cosmic neighbor is
filled with wonders waiting to be
explored Ria with its icy surface
reflecting the distant sunlight stands
as a testament to the beauty and and
mystery of our universe as we continue
to explore and learn who knows what
Secrets this distant moon May yet
reveal well everyone here it is your
most asked for video
Titan and to be fair I can understand
the Curiosity towards it it is the only
moon with a substantial atmosphere
there's clear evidence of stable bodies
of surface liquid on it
and best of all mankind has visited it
so I will be able to show you a lot of
real photos and video
footage I'm Alex molan and you're
watching astram and here is everything
you could want to know about Saturn's
biggest moon
Titan but let's start from the beginning
and give some context to this remarkable
Planet likee
Place Titan is the sixth spherical Moon
from Saturn and unlike Jupiter's four
Galilean moons in the Saturn system
Titan is all by itself in its
size the rest of Saturn's moons are
pretty small in
comparison to give some idea of how big
it is Titan's diameter is 50% larger
than Earth's moon and is 80% more
massive in fact it's the second largest
moon in the entire solar system after
Jupiter's moon ganam it does actually
appear slightly bigger than ganam if you
were to put them directly side by side
but this is caused by Titan's thick
atmosphere which extends its apparent
diameter even so Titan's real diameter
is still larger than the smallest planet
Mercury but it's only 40% as massive as
its density is quite low for its volume
its gravity is reasonably weak at only
0.14 GS or 1.35 m/s squared which is
even less than our
moon due to Titan's low density it is
thought that its composition is half
water ice and half Rocky material
andlike other celestial objects this
size it is believed Titan has a
differentiated interior this means it
has layers and like a lot of other large
moons one of those layers is thought to
be a liquid ocean comprised of water and
ammonia under the moon's crust this
liquid ocean is comparable to Earth's
magma layer situated between the core
and the crust and has been made liquid
due to heat pressure and to a certain
degree tidal forces the existence of
this liquid layer was proven more likely
when Cassini the spacecraft orbit in
Saturn discovered extremely low
frequency radio waves in Titan's
atmosphere Titan's surface is not known
to be a good reflector of low frequency
radio waves but the liquid interior
would be another reason is that the
surface features on the moon have
shifted by up to 30 kilometers since
Cassini started observations which could
imply that the surface is not attached
to the core but is rather floating on
this liquid ocean layer and while there
is no evidence of Life on Titan
scientists do speculate that the
conditions would be right for there to
be life in this subsurface ocean
unfortunately if there was life to be
found on the surface or below we'll have
to wait a while as there no planned
missions to check out this possibility
and Jupiter's Europa is a more likely
candidate to be investigated for life in
the foreseeable future the
differentiated interior of Titan does
not produce a magnetic field Titan is
still quite protected from the solar
wind though as 95% of its orbit around
Saturn is within Saturn's own
magnetosphere Titan orbit Saturn once
every 15 days and 22 hours and has a
rather large orbital eccentricity which
which means the orbit Isn't So circular
its orbital plane is also at an angle
but that doesn't mean that Titan is
likely a captured object rather like
Jupiter's Galilean moons it is thought
that Saturn also had several large moons
in the past but most of these have been
destroyed through big collisions which
left Titan the lone Victor Saturn's
mediumsized moons like IUS and Ria are
thought to be the remnants of this
tumultuous beginning Titan day like the
day on our moon is identical in length
to its orbital period This Means Titan's
rotation is tily locked to Saturn and
only ever shows one face to the planet
not that visually it makes any
difference Titan's hazy atmosphere
completely blocks the view of the
surface from an outside perspective on
the other hand you might just be able to
see sattin while standing on Titan
although the view would be significantly
obscured this does mean however that if
you were to stand on one spot on Titan
Saturn would never move in the sky
removing Titan's Haze this is what it
would look
like this leads us on to one of the
topics that truly sets Titan apart from
the rest of the moons in the entire
solar system its substantial
atmosphere I remember the first time I
ever saw a photo of Titan I was truly
blown away as it never occurred to my
young self that the moon could even have
an
atmosphere I thought it must have been a
new planet they discovered recently or
something to me what looks odd about the
atmosphere is how far it stretches into
space when you see a picture of Earth
you see that the atmosphere has quite a
tight fit around the Planet Titan on the
other hand looks like it has a thick
blanket all over it there are a number
of reasons for this the first one is
that Titan is a lot smaller than Earth
but its atmosphere is 1.9 times more
massive than Earth's or 7 three times
more massive on a per surface area basis
the second reason is that Titan's
gravity is a lot weaker than Earth
meaning it doesn't pull it down as
strongly the mass of the atmosphere
actually means the pressure at the
surface is 1.45 atmospheres or 45% more
than the atmospheric surface pressure on
Earth and comparing the two you can see
the extent of how far Titan's atmosphere
stretches into space 600 km high is only
only the limit of the
mesosphere Earth's mesosphere on the
other hand stops at 120
km even at a distance of
975 km the Cassini spacecraft had to
make adjustments to maintain a stable
orbit against atmospheric drag when it
made its closest
approach like Venus Titan is a super
Rotator meaning its atmosphere rotates
faster than the rotation of the planet
this can especially be seen at the poles
on the moon each pole has a polar vortex
that rotates once every 9 hours compared
to the moon's rotation of 16 days the
vortexes on each pole seem to be like
permanent
hurricanes so what does the atmosphere
consist of and why is it orange in color
well the atmosphere is
98.4% nitrogen the remainder being
mainly methane and small amounts of
hydrogen there are also Trace Amounts of
hydrocarbons from the breakup of methane
in the upper atmosphere due to UV light
and it is these hydrocarbons that are
thought to give Titan its orange Hue
this constant breakup of methane to
hydrocarbons should have meant the moon
ran out of methane within 50 million
years a very short space of time
compared to the age of the solar system
this means there must be a source that
replenishes the methane the most likely
candidate being cryo volcanoes or
although biological life has not been
ruled out the methane in the atmosphere
creates a greenhouse effect without
which the temperature on Titan would be
a lot lower conversely however the haze
also reflects a lot of the sunlight
creating an anti-g greenhouse effect
which cancels out some of the potential
greenhouse effect from the methane now
while Titan's upper atmosphere gets 1%
of the sunlight Earth does due to the
distance from Titan to the sun another
result of this reflection of sunlight
means the surface of Titan only gets
about 0.1% in the end the hyans team
likened the difficulty of taking photos
at this light level to taking pictures
of an asphalt parking lot at dusk all
these things combined means that while
it would be dark a human would only need
an oxygen mask and to wrap up extremely
warm to be comfortable while standing on
the surface of
Titan it really is cold on titanus 180 °
Centigrade on average this means any
water on Titan remains solid and doesn't
ever melt evaporate or subblime then why
are there sometimes clouds on Titan well
these are not water ice clouds but
rather methane clouds which means yes it
can rain methane on Titan in fact the
temperature on Titan is just right for
methane to be liquid methane freezes at
-
182.5 de Cen
and boils at - 161.5 de C the
temperature combined with the surface
pressure got scientists very excited at
the prospect of there being a
hydrocarbon lakes or Seas on the surface
of Titan similar to water lakes and seas
on
Earth If there really were Lakes on this
Moon it would be the first time this had
ever been observed outside of Earth this
was actually one of the main driving
forces behind Cino hyans to see what
there was under that thick atmosphere
the hyans probed named after the
astronomer who discovered Titan in
1655 was designed to enter Titan's
atmosphere and land on the surface the
possibility of even landing on an ocean
was taken into account during its design
process as the probe descended its
parachute was pulled and after an almost
3our Journey it finally rested on the
solid surface of Titan sadly it wasn't
able to see any lakes but what it did
see confirmed that methane Lakes once
existed as hyans landed on what appeared
to be a dried up lake bed these Stones
you see from the surface photos are
rounded Stones much like pebbles found
in a river or a lake on Earth Cassini
from the perspective of space was able
to confirm that methane Lakes are still
found on Titan today near the South Pole
Cassini observed an area which was later
confirmed to be a lake called Ontario
lacus it is 20% smaller than its North
American namesake Lake Ontario so in
other words it is still pretty big at
15,000 square km on this side of the
lake you can see a smooth Shoreline
eroded by waves on the West Side you can
see the first evidence of a river and
Delta on Titan meaning that liquid
hydrocarbons blow down higher Plains to
the lake leaving Delta deposits in much
the same process you had find on Earth
Ontario lacus is extremely shallow only
estimated to be between 40 cm and 3 m
deep the deepest point likely to be just
over 7 m as cassini's radar mapped this
Lake it found that the lake did not have
waves bigger than 3 mm meaning the
surface would appear like a sheet of
glass or a mirror this doesn't mean
there can't be bigger waves unless this
liquid is particularly viscous but the
likelihood is is that it was simply not
a windy day as the observations were
taken the atmospheric density and
gravity on Titan should mean that waves
would be bigger on Titan than they would
be on
earth as the North Pole of the Moon
began to come out of a 15-year winter
another Lake was discovered jingpo lacus
as Cassini was passing by the moon
sunlight was reflected off the surface
of jingpo lacus like a mirror directly
into the view of Cassini upon further
observation Cassini was able to detect
further evidence of moving liquid on
Titan as can be seen by these Rivers
flowing into the
lake the second biggest lake on Titan to
be discovered is liia mar found in the
north polar region of Titan it is bigger
than Lake Superior on Earth with a
surface area of
126,000 square
km while parts of this Lake are
reasonably shallow the average depth is
a lot deeper than Ontario lacers at 50 m
and some parts of it could reach depths
of over 200
M plenty of rivers can be seen flowing
into the
lake and there are large islands found
around this area here a particularly
curious observation Cassini made dubbed
the magic island is the appearance and
disappearance of what appears to be an
island although scientists are unsure
exactly what happened here the theories
are that it could be silt to suspended
in the lake bubbles or subsurface ice
rise into the surface as the lake warmed
during the moon spring but still very
curious the largest lake on Titan at
400,000 square km is the Kraken Mari as
you can see the lake is split up into
two main parts separated by a small
stretch quite similar to Earth straight
of jalta its nickname is the throat of
the Kraken because of tidal forces and
the size of the lake it's thought the
tide changes by about 1 meter and so
this straight may have strong currents
and even whirlpools the Kraken Mar is
also quite deep in comparison to Ontario
lacis but isn't any deeper than 170 m so
we know about the lakes on Titan now but
what other interesting surface features
might it have well plenty actually Titan
surface is quite young as young as a 100
million years old which means its
surface must be geologically active some
scientists believe the dirty ice crust
is substantially rigid although there is
some evidence to suggest that there's
tectonic activity on the moon possibly
caused by tidal forces with Saturn the
main factor of a renewed surface however
is likely to be the same thing that
produces methane in the atmosphere cryo
volcanoes now this is pretty interesting
you know how magma on Earth is pretty
hot but when it comes out of the ground
it freezes well Titan has the same thing
except its magma is water and ammonia
and when it comes out of the cryo
volcanoes and Spills over the land it
too freezes to renew the surface because
of water and ammonia blend is a lot less
viscous than lava it flows further than
lava on Earth this means mountains are
more flat and will never reach the
heights of volcanoes on
Earth while it is hard to confirm
specific cry volcanoes on Titan due to
the obstruction caused by the atmosphere
the most likely candidate is satra
Patera found on the southern hemisphere
in this image height has been
exaggerated by a factor of 10 but it
gives a good idea of the sides of the
Dome and the 1.7 km deep pit the largest
that we know of on
Titan the force necessary for this to
erupt would have had to have been
incredible and while it doesn't appear
to be active now it is is being actively
monitored the fact that Lavon Titan is a
mix of water and other minerals means
the surface could be compared to dirty
ice because we know the hyans bounced
and wobbled in a certain way as it
landed on Titan we have a rough idea of
what the consistency of the surface
could be like scientists have referred
to it as a soft damp sand another theory
is that it's like snow with a thin crust
on top imagine walking on Frozen snow if
you're careful you can walk on a solid
surface but if you stump too hard you
will sink in quite deeply and Titans
believe to be something like
this titans's highest mountains come in
the form of Ridge belts like the Rockies
in
America these Ridge belts could also be
a form of cryo
volcanoes the largest mountain on Titan
can be found in one of these mountain
ranges known as mithrim monts and it's
3,000
337 M High interestingly mountains this
tall are thought to be topped with
methane
snow also found on Titan uh many Gorges
valleys and Junes using infrared cameras
to see the surface from space what can
also be seen quite prominently are these
large patches of dark
terrain originally these dark patches
were thought to be Seas until the hyan
probe landed on one of those areas known
as Shangri La they could well have been
seas in the past but now they are PLS of
dark mineral deposits similar to the
Namib Desert on Earth where they appear
as Windswept Junes in some
places overall Titan can be compared to
Earth in lots of ways scientists think
that Titan show signs of what early
Earth could have been like only much
colder it's fair to say that Titan is
remarkably interesting and I can only
hope it gets his own mission one day
Cassini has done a great job but it was
never a Titan Orbiter and its Mission
will soon be over anyway what I would
find extremely fascinating is to explore
more of its surface and hopefully it
won't be long until a mission to do that
will be approved until then here was
everything you could want to know about
Titan it's been 3 years since Cassini
ended its Mission by diving into the
atmosphere of Saturn its mission was
tremendously successful and it was in my
opinion one of the greatest missions of
all time the data it collected over the
13 years in orbit around Saturn is still
being poured over today as there are
still a lot of Unsolved Mysteries about
Saturn and his
moons one of the most impressive
discoveries of Cassini was confirming
the existence of liquid methane lakes on
the Solar System's most unusual Moon
Titan but knowing they are there didn't
help answer how they came into being but
now scientists may have come up with an
answer I'm Alex molan and you're
watching astram and today we will
explore everything we know about Titan's
leges what Cassini has seen and
discovered and how we now think they
came into
being there are only two places in the
solar system that have stable bodies of
liquid on their surfaces Earth and Titan
that doesn't mean they are very similar
places though Earth is a rocky planet
with an iron Cor core and silicate
mantle Titan is an icy world its crust
and mantle are made up of mainly water
ice with a subsurface ocean of water
surrounding a rocky
core this means Earth is much denser and
coupled with its bigger size means the
gravity on Earth is a lot stronger than
on
Titan Both Worlds have dense atmospheres
but due to their differences in gravity
Earth's atmosphere hugs the planet
tightly while tightens although a little
more massive in total than Earth's
stretches hundreds of kilometers above
the moon's
surface their compositions are also
different Earth is much closer to the
Sun meaning it is much warmer than Titan
which allows there to be an active water
cycle water is Frozen On Titan however
the temperature is just right for liquid
methane to be present on its surface
that means yes Titan experiences a
methane cycle in a similar fashion to
Earth's water
cycle methane clouds have been spotted
in Titan's atmosphere and these clouds
re liquid methane onto Titan's frigid
surface this process carves Out Rivers
through the surface IES that flow into
small Seas or Lakes radar data from
Cassini visualized in these images
clearly show various riverbeds and
valleys cut away by the flowing
methane the most prominent of these flow
channels are found around Titan's second
largest lake liia
Mar these channels dubbed vid flumina
are special because they look to be much
older than any other flow channel on the
moon the Canyons have walls hundreds of
meters tall with very steep
slopes liquid methane is visible in the
canyon but right now it isn't flowing
rather it is likely to be a drowned
River Valley due to the level of liia
Mari although some high altitude tribut
trees are likely to still be flowing
down into the
canyon the legs on Titan can be huge the
biggest one the Kraken Mar is bigger
than the Caspian Sea on Earth at roughly
400,000 square
km the radar data suggests that a lot of
these Lakes are very shallow some of
them only a few meters deep some of the
larger ones however can have depths of
over 200 M all in all this the total
amount of potential fossil fuels on
Titan to over 300 times The Proven
amount on
Earth the legs of Titan are surprisingly
still some legs do not have ripples
larger than about 1 mm meaning it would
appear like a glass or a
mirror this came as a surprise to
scientists who expected waves of up to a
meter in height due to the low gravity
and dense atmosphere blowing over the
surface this could mean that they're
just just so happened to not be any wind
as Cassini passed over the lakes are a
lot more viscous than expected or that
they occasionally freeze over one other
theory has been proposed and that is
that dense aerosols May sit on the
Lake's surface creating a film which
prevents waves from
forming the detection of lakes on Titan
couldn't be possible without the aid of
cassini's radar instrument an infrared
camera to see through Titan's thick Haze
these instruments use a process called
specular reflection to make observations
the radar instrument detected large dark
patches across the surface which were
later confirmed to be Lakes by the
infrared camera when sunlight reflected
off the lake and into cassini's view a
bit like what you sometimes see of Earth
from
space specular reflection with the
infrared camera and the sun ended up
being used a lot to confirm what the
radar cirular reflection was seeing
interestingly clouds and the subsequent
effects of their rain were also detected
in the left image you see a light patch
indicating dry ground but a year later
the area was imaged again and this time
darker patches can be seen indicating a
very flat surface highly likely to be
shallow and small
lakes the Lakes aren't distributed
evenly across the moon rather most of
them are found near the
poles however the hyan probe which was
part of the Cassini Mission and landed
on Titan surface near the equator did
see flow channels around the equator too
but where are the Lakes these channels
would flow into well this is thought to
be the result of seasonal variations
like summer and winter producing
different types of weather on Earth at
certain points in Titan's year rain
would fall in these parts and pool on
the surface however these probably
evaporate during the rest of the year
and the rain migrates to the North and
South which is what Cassini and hyans
would have observed even though Cassini
was in orbit around Saturn for 13 years
that's not even one half of a saturnian
year Saturn takes a full 30 Earth years
to orbit the sun once so Cassini didn't
capture a complete picture of all the
seasonal
variations the Lakes likely vary in
depth throughout the year with some
potentially drying up
completely there is one other mystery
that was thrown up by the Cassini data
to do with Titan's Lake that may have
recently been solved some of Titan's
smaller Lakes have very steep rims that
Tower above the lake level this is
unusual as Lakes on Earth typically form
from erosion processes and dissolving
Limestone meaning the rims are shallow
and smooth these are called castic leges
but this process doesn't add up for a
number of Titans Lakes scientists now
believe that these could be explosion
craters that have since filled up with
liquid methane models suggest that Titan
was once colder with nitrogen rain and
snow instead of methane this liquid
nitrogen would have seeped into the
crust creating pockets of liquid
nitrogen as the greenhouse gas methane
was pumped into the atmosphere by cryo
volcanoes in Titans past the world
warmed and would have caused the liquid
nitrogen now trapped under the surface
to evaporate and expand building the
pressure in the pocket until the lid
basically blew off leaving an explosion
crater there is still a lot to be
learned from the Cassini data the lakes
of Titan were just a small aspect of the
mission and scientists are going to be
piecing these puzzles together for years
to come better understanding the satin
system as a whole I really hope future
space agencies will be as ambitious and
as successful as the Cassini Mission
there is still an awful lot to discover
out there
[Music]
Enceladus perhaps one of the most
intriguing objects in the entire solar
system and yet it is only the sixth
largest moon of Saturn and in natural
light it looks very
unassuming however there's a lot more to
Enceladus that meets the eye it's an
active icy world with jets of water
vapor pouring out from its southern
hemisphere thanks to the remarkable
casin SC Mission we have studied and
observed Enceladus in Exquisite detail
and perhaps know more about it than some
of the closer and bigger Jovian
moons however although we've seen a lot
from the outside it's the inside of the
Moon that still holds so many
Mysteries I'm Alex molan and you're
watching astram and together we will
explore some of the most fascinating
details of Enceladus piecing together
photos and data from a variety of
missions to find out almost everything
you could want to know about this
special Moon so stick with me on this
journey of
Discovery let's first of all discuss
where Enceladus fits into our solar
system Enceladus is currently Saturn's
14th closest Moon I say currently as
Saturn has some tiny moonlets hidden in
its rings that may or may not be
classified as moons in the future it is
the second closest major Moon though
second only to mimus that means that its
orbit takes it just outside of Saturn's
major Rings its orbit follows the planes
of the Rings very precisely and it only
takes 33 hours to orbit Saturn
once interestingly it is in a 21 orbital
resonance with dioni Saturn's fourth
closest major moon in other words it
orbits twice around Saturn in the time
dioni orbits once this orbital resonance
is believed to prevent enceladus's orbit
from ever becoming perfectly circular
which causes Enceladus to undergo tidal
deformation this is significant as these
tidal forces heat up enceladus's
core you see as far as we can tell
enceladus's surface is predominantly
made of Clean Water certainly with
little to no rocks or much else there
because Saturn is situated so far away
from the Sun it means the outer layer of
water on Enceladus has frozen over
Enceladus is essentially a frozen ocean
World a giant ball of water
ice because it is free from other
materials on the surface the Moon is one
of the whitest objects in the solar
system with a bond albo of
0.81 which is pretty much as high as
snow as such it is one of the coldest
satellites of Saturn with a noon
temperature of -2 200° c as the white
color of its surface reflects a large
percentage of the sunlight reaching it
back into
space however about 30 to 40 km Down
Under the surface of Enceladus pressure
start building and heat energy generated
from the tidal deformation of its orbit
has increase the temperature of the
water ice to the point where the water
at this depth can exist in a liquid form
it could well be that there is an entire
mantle or a global ocean of water that
the ice crust is resting upon very much
like the magma mantle that our Rocky
crust on Earth rests upon at the very
least scientists expect there to be a
huge pocket of water under the moon's
South Pole how do we know this well the
most obvious indication are the huge
plumes of water being ejected from the
cracks in the crust something referred
to as water or cryo
volcanism these jets are really active
consistently blasting around 250 kg of
water into space every second
at speeds exceeding 2,000
kmph this is powerful enough that most
of the water vapor particles Escape
enceladus's weak gravity and they end up
in orbit around Saturn forming Saturn's
earring this ring around Saturn is very
diffuse and so isn't really visible
unless it is back lit by the
[Music]
Sun from this angle the light shining
through the water particles make the
ring appear exceptionally BL blue in
fact this ring is considered the bluest
object in the solar system even more so
than Neptune due to the Ring's
uniformity the earring is Saturn's
second outermost ring and it is 2,000 km
wide its shape is also heavily
influenced by the orbit of Enceladus
enceladus's plumes create tendril shapes
in the Rings as more material erupts out
of
it however these sections of the Ring
tend to smooth off as in cadus moves
further away Along its
orbit during the course of cassini's
mission Cassini was able to pass through
these plumes to detect the substances
being ejected from
them Cassini wasn't designed with this
in mind scientists didn't know about the
plumes until Cassini got there however
Cassini was equipped with an instrument
called The Cosmic dust analyzer designed
to detect what the tiny dust grains in
orbit around Saturn are made of and it
was able to use it for enceladus's
plumes
too as it wasn't specifically designed
with this in mind it might not have
given us the full picture of what's in
these particles but while water was the
predominant substance detected amino
acids carbon dioxide nitrogen and
methane were also found amino acids are
significant as they are the building
blocks of life and can be found around
the thermal vents at the bottom of
Earth's oceans does this mean Enceladus
has thermal vents of its own
and if so do they have ecosystems of
life around
them while evidence for an underground
ocean is abundant scientists still
aren't completely sure about enceladus's
internal structure at some points in the
past scientists believe that Enceladus
was water all the way through however
data from Cassini suggests that
enceladus's mass is in fact greater than
previously thought meaning it must have
some amount of iron or silicate material
in its core
scientists are starting to lean towards
the theory that the internal structure
is differentiated meaning it's a
Celestial body with defined layers
within it an object of this size really
doesn't have to be differentiated in
fact it's so small at only about 500 km
across that it is right on the
borderline of being in hydrostatic
equilibrium or in other words being
rounded by its own gravity there are a
number of objects out there of similar
or smaller sizes that are not in
hydrostatic equilibrium like Neptune's
Proteus in any case assuming it does
have a differentiated interior this core
is likely to be predominantly Rocky this
is important as thermal vents in
enceladus's water ocean would have to
come from a rocky core a rocky ocean
floor would also provide nutrients and
minerals essential for what we believe
life would need to form and evolve
thermal activity clearly does exist due
to the way Enceladus has plumes in the
first place and the amino acids detected
in the plumes suggest a rocky
core as Cassini passed over Enceladus it
also mapped out the thermal emissions
from the Moon it turned out that the
Jets line up with what has come to be
known as enceladus's tiger stripes these
are large depressions roughly 130 km
long 2 km wide and 500 M deep it is
believed that these are Tech tonic
fractures in the moon's icy
crust what is really interesting about
the surface features of Enceladus is
that there are virtually no impact
craters at all over the Southern
Hemisphere and not many anywhere
else this implies that enceladus's
surface is very young as while it does
have a thin atmosphere made up from the
ejected water from the plumes this isn't
nearly enough to burn up asteroids
before they hit the surface some water
from the plumes obviously settles again
on the surface which Smooths it off over
time this is another reason why
Enceladus is so round for such a small
Celestial
body in fact apart from the tectonic
fractures and few craters enceladus's
topographical variation is really quite
minimal there are no mountain ranges to
speak of although there is what you
might call a rough terrain around the
South Pole if you zoom in far enough
this is perhaps the highest resolution
image we have of its surface and as you
can see it really does appear like a
giant Glacier it's interesting to note
that even in this small view there are
some smooth sections of ice but also
Jagged
regions over the North Pole the clear
difference is the number of craters
present there while there are tectonic
fractures here too there are no plumes
on this side of the moon so the surface
here is clearly a lot older than around
the South Pole which is why it has more
of a crated surface as Cassini flew
through the plumes around the South Pole
it also took the opportunity to image
the surface closely around the tiger
stripes the surface here is pretty
incredible unlike anything you would
have seen on Earth it's like the surface
has been folded squashed and shifted
around leaving these remarkable fracture
lines and formations in the surface ice
the fact that Cassini was able to get so
close to Enceladus is a feet in and of
itself it's fantastic that we can have
such a close up view of something so far
away unfortunately though since the
Cassini Mission has ended we no longer
have anything in orbit around Saturn
that can study Enceladus
further there have been plenty of
mission proposals in the past but all of
them were cancelled before they came to
fruition what would be incredible is a
probe that could either make its way
into enceladus's ocean somehow or at the
very least search the plumes for signs
of Life there is already a mission
called dragonfly going to the nearby
Moon of Titan however this won't have
anything to do with
Enceladus so although a couple of
mission proposals are currently under
review to go there that means we are
unfortunately still a couple of decades
away at least which is a shame because
who knows what Secrets lie in weight
under that
crust so there we have it a look at the
Intriguing little Moon of
Enceladus the scene is set your arch
rival has got you pinned gun pointed at
you with your back overlooking the drop
of the tallest cliff face in the solar
system Verona rupes this 20 km drop is
roughly 16 times bigger than the tallest
cliff face on Earth Mount Thor in Canada
coming in at a mere
1,250
M the only Advantage you have right now
is that you are standing on Miranda a
tiny 470 km wide Moon of Uranus meaning
the gravity here is weak do you jump and
take your chances with the drop or have
you got more chance with the gunman well
let's have a look at a few
factors Miranda is the smallest of the
five circular moons of Uranus being only
470 km across put it right on the edge
of being in a hydro static equilibrium
or in other words it's just about big
enough to be spherical under its own
gravity it's also not very dense thought
to consist of at least 60% water ices
its small size and low density means its
gravity is very weak just for a
comparison on Earth gravity accelerates
you towards its surface at 9.8 m/s
squared on our moon that's reduced to
1.6 m/s
squ on Miranda it's just
0.08 m/s squ that means should you jump
you would have a very gradual descent
towards the
bottom but there's another Factor while
falling on Earth after a certain
distance you would reach terminal
velocity air resistance combats the
acceleration of gravity which means your
speed would eventually cap out in a
lying position this is 200 km an hour
without Earth's atmosphere jumping out
of a plane would mean you hit the ground
extremely fast as there is nothing to
slow you down and Earth's gravity is
pretty
strong Miranda has no atmosphere again
this means there would be no air
resistance to slow your fall so although
you're falling very slowly at first your
speed would begin to pick up with
nothing but the base of the cliff to
eventually slow you down
as I mentioned Verona rupes is a massive
20 km tall such a tall Cliff can exist
on Miranda because its gravity isn't
strong enough to pull it down we don't
really know how it Formed like this as
Miranda should be too small for plate
tectonics one theory is that water under
the ice crust froze and expanded forcing
the surface to split creating Canyons
hundreds of kilometers long so a 20 km
drop with an acceleration of 0.08 m/s
squared well you may not be surprised to
find out that it will take you a long
time to reach the bottom of the cliff 12
whole minutes that means it won't be a
The Fugitive scenario where Harrison
Ford quickly jumps off the dam before
Tommy Lee Jones can do anything about it
your arge rival will have to be quite
slow to allow you to jump off before he
can shoot you
and should that all go well by the time
you reach the base with no atmosphere to
slow you down you will be traveling at
200 km an hour a parachute won't help
you here but a really big airbag or
little Rockets might do the job so there
you have it what would happen if you
fell from the tallest cliff in the solar
system Triton is an exceptionally
unusual although often forgotten
Moon it has so many unique
characteristics it makes it one of the
most interesting objects in the solar
system but because it is the largest
moon of Neptune the planet furthest away
from us it also means that we have only
visited it
once very briefly as Voyager 2 flew by
all the way back in 1989 30 years
ago but what did the visit reveal and
what have we found out about it
since I'm Alex molan and you're watching
astram and together we will find out
everything there is to know about the
fascinating world of
Triton first of all let's discuss where
Triton fits into our solar system and
its local
system Triton is one of 14 known moons
of Neptune seven of these moons are
regular
moons or in other words moons that orbit
along Neptune's ecliptic with very
circular orbits or orbits with very low
eccentricity after these inner regular
moons we get to The Irregular moons the
first of which is
Triton an irregular moon is a moon that
follows an inclined eccentric and often
retrograde
orbit this by itself is already where
Triton is set apart from any other
spherical Moon in the solar system it
has an irregular
orbit Triton orbits clockwise around
Neptune as Neptune rotates
counterclockwise and Triton orbits at a
130° angle to the ecliptic of the
planet although it should be noted that
its orbital eccentricity is close to
zero its orbit is almost perfectly
circular all other large moons in the
solar system are regular MO moons
orbiting the same direction as the
rotation of their parent
Planet what this heavily implies is that
Triton did not form alongside Neptune
but it is in fact a captured
object specifically a captured dwarf
planet no wonder then that it is by far
the biggest of Neptune's 14 moons
comprising
99.5% of the mass found in Neptune's
orbit but how big is that in Scales we
can relate
to well it is the second largest moon in
relation to its parent
Planet second only to earth and its
Moon while it is smaller than our moon
it orbits closer to Neptune than our
moon orbits Earth which means it appears
about the same size in the
sky it is the seventh largest moon in
the entire solar system and most
interestingly it is bigger than Pluto
Pluto is often considered the King of
the Kyer belt the biggest object that we
know of that formed there until we
consider that Triton once ruled that
area before Neptune captured
it so although Triton is a moon of
Neptune it could be said that it is the
biggest and most massive Kyper belt
object further evidence for this was
found as New Horizons past Pluto in 2015
suggesting Triton and Pluto share a near
identical composition which supports the
theory that they share a common
origin Beyond tridon are six other
irregular moons found much further out
they are almost certainly captured
objects too with unusually eccentric
orbits that take years to complete they
were probably perturbed into these weird
orbits by the gravity of
Triton so if Triton was a captured
object how did that happen objects need
to lose momentum to be captured
otherwise they would have enough
momentum to
escape well we can't know for sure but
the leading theory right now is that
Triton was once part of a binary system
perhaps like Pluto and
cheron as Neptune approached Triton and
its Moon the Gravity from the encounter
would have caused the binary system to
fall apart with Triton's Moon being
slingshot away and Triton losing enough
momentum to be captured in orbit around
Neptune I mentioned that Triton shares
similar characteristics with Pluto what
exactly does that
entail well they both have a
predominantly nitrogen ice surface with
other ices mixed in like water and
carbon
dioxide it has quite a flat terrain its
topography never varies by more than a
kilometer although Voyager 2 did see
ridges and troughs plateaus and Ice
planes what you may find unusual though
is that it has very little in the way of
craters this implies its surface is very
young and is constantly being
renewed like Pluto it also has some
reddish patches which is thought to be
methane having reacted to UV light from
the sun producing what is known as
tholins an organic compound that has a
supposedly tar like consistency
while organic compounds do not mean life
is present there organic compounds are
the basic chemicals from which life
forms life likely couldn't exist on the
surface of trit in anyway as it's far
too cold and the sun far too dim to
support any life form that we can
imagine but what's interesting is what
could be found under Triton's
crust under Triton's surface is thought
to be a Rocky and metallic interior
which gives Triton a reasonably high
density for a moon at 2 G per cm
cubed because of this and also due to
the big step up in size from the next
biggest moon in the solar system Titania
it has more mass than all the moons
smaller than it in the whole solar
system
combined the radioactive decay from the
rocky core could be enough to heat and
power convection in a subsurface ocean
of water much like what is thought to be
under the services of Europa Enceladus
and some other large moons in the solar
system and just like euroba and
Enceladus cryo volcanism is an active
process today on
Triton liquid water in the mantle erupts
onto the surface like lava on Earth this
is the main reason why the surface is so
young it is being actively renewed by
liquid water erupting and then freezing
on Triton's
surface some very young lava planes have
been identified sparse and flat regions
yet interestingly with a wall that
surrounds the plane this is called a
plena or in other words a solidified
Lava
Lake we also can see cauld which is the
collapse found at the center of a cryo
volcano where lava planes formed
from it is thought that the water from
these eruptions would have also brought
minerals from the underground oceans
onto the surface perhaps even being the
source of the tholins and organic matter
I mentioned earlier
if this is the case and organic
compounds are found in the subsurface
ocean it means that there's a
possibility that conditions are right
for life to have been able to form
there we also see long lines permeating
over the surface these are likely faults
caused either by tectonic activity or
freeze thorw weathering
processes if we look at some more of the
Voyager 2 images of Triton we can see
the results of some recent eruptions
you'll notice what looks to be dark
deposits on the surface in cone or
funnel-like shapes up to 150 km long
however these smaller eruptions may not
originate from the mantle
itself Voyager 2 spotted some plumes
reaching 8 km high but these are thought
to be because of a solid greenhouse
effect within the moon's icy
crust imagine the surface of Triton
consisting of a clear ice which is
settled on dark deposits like tholins
the sun shines through the ice warming
the darker more absorbent tholins
beneath which sublimes a pocket of ice
under the surface as the ice is Sublime
the pressure builds in the air pocket
until the surface above the pocket gives
way causing an
eruption this eruption also takes the
dark deposits with it spreading them out
over the surface
again if this is the case a very similar
process has been seen on Mars's poles
with carbon dioxide I and darker
deposits under the ice
layer this process can only exist
because of one thing Triton has an
atmosphere although not as thick as
scientists were initially
expecting Triton's atmosphere is thin
only
0.014 mbars about the equivalent of 80
km up on Earth although like Pluto the
this density varies through seasonal
changes since Voyager 2's observations
Triton's atmosphere has become denser as
the surface is warmed evaporating a
little of the nitrogen IES on the
surface however when Voyager too past
Triton's atmosphere was still dense
enough to support weather up to 8 km
above its surface in this image you can
actually see clouds on
Triton and going back to the image of
the plumes you can see the deposits from
the eruptions all end up facing the same
direction due to a prevailing wind in
that region of the
moon like Pluto Triton's atmosphere is
hazy the cause of which is thought to be
hydrocarbons in the atmosphere not yet
broken down into tholin by UV light from
the
sun the constant depositing of organic
compounds through cryo volcanism I is
evaporating and freezing again through
seasonal variations and a weather Rich
active atmosphere makes Triton a very
Dynamic World unlike most other moons in
the solar
system it is more a dwarf planet than a
moon likely a sibling of the more famous
Pluto in the Kyer
belt all of these factors combined make
it one exceptionally unusual
Moon and there we have it everything you
could want to know about Triton
thanks for watching I really want to
give a huge thank you to our astronauts
on patreon it's really becoming a
thriving community and I've Loved
reading all your messages and comments
over there if you'd like to join in then
you can visit the link in the
description to become an astrom note and
bring the channel more stability than
the algorithm when you join you'll be
able to watch the whole video adree see
your name in the credits and submit
questions to our team meanwhile click
the link to this playlist for more Asom
content I'll see you next time