The answers to some of our solar systems
oldest mysteries lie locked in dust and
ice. Asteroids.
These time capsules are relics from
before Earth was fully formed. And if we
can uncover what lies within them, we
can better understand our own origins.
So, it is no wonder that NASA has many
missions tasked with imaging them. There
have even been a few that have collected
samples from the coma of comets. But as
for a NASA mission that traveled to an
asteroid, touched its very surface, and
endeavored to bring a sample back, there
has only ever been one. Osiris Rex. This
little heard of mission was instrumental
in advancing our understanding of a time
before our planet. But its journey to
and from the asteroid known as Bennu was
not all smooth sailing. What did it do
there? What were its mission goals? And
what did this NASA mission like no other
ultimately uncover on that tiny frozen
world?
I'm Alex Mccoan and you're watching
Astramm. And together we will go through
everything you could want to know about
the Osiris Rex mission.
Let's start from the beginning. Osiris
Rex is part of the New Frontiers NASA
program along with Juno and New
Horizons, which means it's part of a
high pedigree if you've been following
those other missions. It launched in
September 2016 and arrived near Bennu on
the 3rd of December 2018 where it began
imaging the surface. But Osiris Rex is
not just an imager. You see, unlike most
robotic NASA missions that don't return
to Earth, Osiris Rex is unique in that
it is a sample return mission. The first
time NASA would attempt this with an
asteroid. Although, it should be noted
that Japan's JAXA program had done this
before with the Hayabusa mission and
again with Hayabusa 2. But why
asteroids? Apart from the curiosity
factor, is there anything that actually
makes asteroids special?
Well, asteroids are remnants of some of
the oldest objects in our solar system.
They were there when everything was in
the process of forming around the sun.
To this end, asteroids can tell us a lot
about the formation of the solar system.
They are the building blocks of planets
and also potentially life. Asteroids
could be the source of water on Earth
and they mysteriously contain organic
materials like hydrocarbons and amino
acids. Actual uncontaminated samples of
asteroids will provide insights into
this, enabling us to have a better
understanding of the universe we live
in. And tempting though it is, we cannot
simply study the asteroids that come to
us.
While there are a lot of meteorites that
land on the surface of Earth and we have
many, many samples, these meteorites
pass through our atmosphere, heating up
to incredible temperatures, which alters
the delicate materials in the meteorite.
Upon impact, they are also then exposed
to the surface of the Earth, making it
hard for scientists to distinguish what
was there from before and after the
impact. A sample directly from an
asteroid protected in a box from
contamination which occurs during the
re-entry process can give a much greater
insight into the nature of asteroids
than anything we have observed before.
With this sample, scientists would be
able to search for organic compounds
like amino acids, hydrated materials
like clays, and other substances that
would otherwise be hard to detect.
Bennu is an extremely old asteroid. It
is thought to have been around since the
birth of the solar system and as such is
a treasure trove of information about
the solar systems formation and maybe
even the origins of life. So NASA
reached a decision. While missions have
photographed asteroids before and have
even collected stardust from the tails
of comets, this was to be the first time
a NASA spacecraft would ever travel to
an asteroid to physically collect a
sample from its surface. So, the stakes
were high.
NASA's goal was to collect a 60 g sample
of Regalithan dust from Bennu's surface.
It would do that by entering Bennu's
orbit and slowly descending. It would be
careful not to disturb or contaminate
the asteroid surface by using its
thrusters, but would drift gently down,
extending its long touchandgo sample
acquisition mechanism, or tags, as it
did so. Then, at the moment it touched
the surface of the asteroid, it would
release a burst of nitrogen gas from its
arm, kicking up dust and materials,
which would be captured in its sampler.
Osiris Rex would then return home with
its sample.
Interestingly, once it had collected the
sample, Osiris would find out how much
mass it has in a really clever way. It
would do a spin to see the change in
inertia with this added weight. If it
wasn't able to collect enough samples,
it would go in for another try. And so,
Osiris Rex began its journey. Although
Bennu is a near Earth asteroid, it also
took more than 2 years to get there.
This is because Bennu does not orbit
along the plane of Earth and his gravity
is incredibly weak, which means Osiris
Rex had to slow down a lot or it would
have simply overshot its mark.
Interestingly, the Osiris team had a
pretty good idea of what Bennu would
look like long before Osiris Rex even
launched. This is because they used
radar data to simulate what it would
look like. As Osiris Rex approached
Bennu, the images it sent back were
progressively clearer and clearer, and
the Osiris team saw that their
predictions were surprisingly accurate.
Eventually, it got to within 20 km of
the asteroid, and what it saw was
amazing.
This is an actual time lapse of the
Bennu asteroid as seen by Osiris Rex. If
you compare the simulation to the actual
photographs, it's amazing how accurate
their predictions were. As you can see,
it's not a particularly smooth asteroid
covered with rough regalith all over the
surface. It reminds me a lot of the
surface of another asteroid that was
visited by the Jaxa probe Hayobusa, the
asteroida,
which was more like a clump of rubble
than anything else. Bennu itself is
about 500 m in diameter and has this
weird spinning top like shape. This
could be because Bennu has a low gravity
but a fast rotation. So Regalith has
accumulated there as the asteroid span.
Bennu is a carbonatous asteroid but in
the less common Btype classification.
This puts it in the same category as the
third biggest asteroid in the solar
system, Palace. and Bennu could even be
the ejector from an early impact in
Palace's life. Btype carbonatious also
means it has a very low albido or that
it doesn't reflect a lot of sunlight.
Other tests showed that it could be an
even rarer FT type asteroid instead and
as such could have been part of the Pana
family of asteroid, meaning it would
have come from the 55 km big asteroid
Palana. In either case, its orbit has
changed significantly through various
processes and interactions to bring it
close to the orbit of Earth. Speaking of
its orbit, it is one of the most likely
asteroids we know of that could impact
Earth. Although, based on the most
recent estimate in 2014, this won't
happen until 2175.
And even then, there is only a 1 in
2,700 chance of doing so.
Before Osiris Rex went into orbit around
Bennu, it first needed to see if there
were any small moons or debris around
the asteroid so there wouldn't be any
risk of a collision. It did this by
going back and forth a few times around
the asteroid, also getting a sense of
the gravity of an object so small. Once
the prime orbit had been located, Osiris
Rex took up an initial orbit of roughly
1.75 km above its surface.
Interestingly, this means that Bennu was
the smallest world ever to be orbited by
a spacecraft.
A 500 m wide object like Bennu barely
has any gravity at all, which means one
orbit of Bennu took 62 hours at that
altitude. However, orbiting Benny was
necessary to map its surface accurately.
As the spacecraft orbited and the
asteroid rotated, Osiris Rex was
scanning the surface, creating the
highest resolution map of any celestial
body to date. Did Osiris Rex find
anything interesting during its
preliminary scans? Absolutely.
Osiris Rex wasn't just taking photos of
the asteroid, but it was also mapping
the global properties, chemistry, and
minology of this primitive carbonatous
asteroid to characterize its geologic
and dynamic history. to provide context
for the returned samples.
Spectroscopic surveys quickly revealed
that there are hydrated materials or in
other words clays on the surface of
Bennu. This is significant. Clays
contain water and Bennu was not the type
of body where scientists expected to
find any.
Scientists are still of the belief that
a body as small as Bennu could never
have held its own water. But what this
does imply is that liquid water was
likely present on the body would have
originated from and all that remains of
it is what has been locked away in these
clays. But while these discoveries were
interesting, ultimately Osiris Rex was
doing this to help pick the best site
for the sample return part of the
mission. Scientists were looking for the
most geologically interesting site that
could provide the most interesting
sample.
But on that front, a problem had already
arisen.
While scientists had previously mapped
out the rough shape of Bennu to a
surprisingly high degree of accuracy
using radar imaging, Bennu's small size
and corresponding low gravity had led
them to believe that Bennu would be made
of relatively fine materials.
This was not the case. Bennu was covered
in large boulders, some of which were 58
m across, 20 m high, and about the size
of a football field. Other boulders you
see here are about the size of a horse.
Many asteroids have been described as
rubble piles in the past, but I don't
think anyone was expecting it at this
scale. This makes picking a landing site
a little tricky when ideally you are
looking for a patch roughly 25 m in
diameter containing particles no bigger
than a cm so your sample collector can
retrieve a sample safely. However, in
the face of this unexpected obstacle,
after a year of circling, four smaller
landing sites were eventually chosen,
named Osprey, Kingfisher, Nightingale,
and Sandpiper. Even though they were
smaller sites than originally hoped for,
the sites were relatively free from
boulders. You might notice a bird theme
here. Bennu itself was named as the
result of a contest run by the
University of Arizona, the Planetary
Society, and the Linear Project in 2012.
In it, more than 8,000 students
submitted name ideas. The winner was a
third grade student who wanted to name
the asteroid after the Egyptian
mythological bird Bennu because he
thought that the Osiris Rex's Tagam arm
looked like the graceful extension of a
heron's neck, just like the Egyptian god
Bennu. meaning it was named after the
craft visiting it rather than the shape
of the asteroid itself. NASA seems to
have kept with this birdlike naming
convention.
By the end of 2019, Osiris Rex had been
circling Bennu for a year, but that year
was not wasted. On top of what we've
already talked about, yet more
discoveries were being made. Considering
Bennu is seemingly an inactive pile of
rocks floating in space, Bennu also
surprised scientists greatly when Osiris
Rex spotted some dynamic activity on the
asteroid. Occasional ejection events
were spotted where some material was
flung away into space. Some of these
particles were even captured in orbit
around the asteroid for a few orbits
before eventually returning to the
asteroid surface. This is likely due to
the fast rotation of the asteroid and
Osiris Rex was able to detect that this
rotation is speeding up very gradually
due to the EORP effect. This effect is
caused by the slight pushing effect from
solar radiation acting on an irregularly
shaped object causing it to rotate
faster over very long periods of time.
The speed of the rotation can already be
seen due to the buildup of rocks along
the equator through centrifugal forces.
If the rotation continues to speed up,
then the asteroid might eventually
disintegrate altogether when centrifugal
forces overcome the gravity of the
asteroid. This can already be seen in
small events like the one I showed you
before. In the end, Osiris Rex spent
over a year, 505 days, circling Bennu
and mapping out its surface, choosing
the best location for its system
spanning pogo stick hop, where it would
land its sample collector onto the
surface of Bennu before firing off again
with its thrusters. At last, the moment
of truth had come. NASA chose the
Nightingale site for Osiris's landing.
The site was set in a crater that seemed
to be relatively young and clear of
rocks, which came with numerous
benefits. Not only would landing be
easier, but the recently exposed
material beneath Bennu's surface would
likely be an accurate reflection of the
asteroid's internal workings.
With the site selected, Osiris began its
slow descent.
However, it did not rush in with a
single try. Instead, it did practice
runs. The first took place on the 15th
of April, 2020. Osiris Rex approached
the asteroid to a distance of 65 m
before activating its thrusters and
rising again. Everything worked
perfectly and its thrusters worked just
as intended. Satisfied with this run,
scientists sent it in again. On the 11th
of August, Osiris Rex approached at a
distance of 40 m before once again
rising, slowly darting forwards and
backwards, but drawing ever closer. And
on the 20th of October, this heron
lookalike went in to strike
using onboard computer systems to plan
its trajectory and perform its
operations. As the lag time for signals
from Earth rendered real-time remote
control of the spacecraft impossible,
Osiris slowly reached out to touch the
surface of the asteroid.
It raised its solar panels in a Y shape
to keep them out of the way and protect
them from any loose dust that was about
to go flying. It reached out its arm to
land. It touched the surface and then
surprisingly it kept going.
When I think of the surface of asteroids
and comets, I imagine them as firm and
hard enough to stand on as you might see
in films such as Armageddon. But the
truth is that particularly for small
asteroids like Bennu, their low gravity
means that their mass is only loosely
held together. What looks like a stable
surface is actually loosely held
material interspersed with pockets of
nothingness. gaps that mean Bennu is so
easy to sink into, if you stepped on it,
you'd likely vanish inside of it.
Like stepping into foam, Osiris Rex's
arm sank almost half a meter into the
surface of Bennu before the thrusters
arrested its fall. Furiously activating
its nitrogen gas burst, Osiris blasted a
hole in the side of the asteroid. What
was expected to kick up a little
regalith and dust displaced over six
tons of loose rock as all that material
so loosely held together under Bennu's
tiny gravity was catapulted in all
directions.
Osiris Rex's thrusters went into
overdrive, burning the most they had
ever burned on this trip to pull them
away from the expanding cloud of dust.
Of course, this was all pre-programmed.
NASA had planned for this, although
perhaps not to this extreme. Osiris Rex
had just made a new massive crater in
Bennu.
Upon getting away from the asteroid
surface, Osiris Rex checked its hall.
Remember, it had hoped for 60 g of
material. Instead, it found it had
collected somewhere between 400 g and
over 1 kg of material.
So much material had been collected that
a rock got stuck in the flap that closed
the sampler's head, causing some small
amount of the material to get lost.
However, Osiris Rex succeeded in
transferring the sampler head to a
sealed container built into it. Its
mission had been a huge success.
For a time, Osiris Rex stayed watching,
flying over the asteroid to image it and
see the outcome of what it had done. The
surface of Bennu was different now. Even
larger materials had moved far. Just
look at how far this boulder was thrown.
Around 12 m across Bennu's surface.
However, Osiris Rex couldn't linger
forever. Its sample needed to get back
to Earth. And so, after performing one
last flyby on April 7th, 2021, it began
a long journey home.
It had been a long time since Osiris Rex
had left the Earth. 7 years of
anticipation, space travel, and data
sample collection had passed since that
first fateful launch. But after a 2
years and 4 months and 1.9 billion km
homecoming journey, Osiris Rex returned
to Earth in September 2023.
Or rather, it passed by Earth in order
to return its special cargo. As the
spacecraft reached a point about 100,000
km away from our planet, it jettisoned
the sample return capsule towards the
atmosphere on the 24th of September.
Then Osiris Rex fired its thrusters to
avoid itself colliding with Earth and
began a new mission, which we'll talk
about later.
This calculated maneuver had to happen
within a narrow window of time and
adjust the right angle in order for the
return capsule to hit its target of
about 600 km in a Utah desert in the
western United States. That's roughly
the size of the city of Chicago or the
size of the aisle of man.
As the capsule hurtled towards Earth at
a top speed of 43,000 kmh, it became the
second fastest human-made object to
enter Earth's atmosphere, only 3,000
km/h slower than NASA's Stardust return
capsule and enduring an astounding 32g
forces, or 32 times the acceleration due
to Earth's gravity. To put this into
context, standing on Earth, you receive
one G, and a typical person would lose
consciousness with about four to five
vertical G's. Today's astronauts
experience about 3 G's during launch.
And for very short periods of time, a
fighter pilot may be able to withstand
up to 8 or 9 GS with the help of a
specialized suit and training to
increase their tolerance. It's almost
unfathomable to imagine the 32gs the
return capsule was built to withstand.
The scalding hot capsule stre through
the atmosphere, reaching peak
temperatures of around 2,700°,
which is about half as hot as the
surface of the sun, allowing groundbased
infrared trackers to monitor its
progress. Inside the capsule, the 120 g
sample from asteroid Bennu was protected
from these extreme temperatures thanks
to an advanced thermal protection system
called PA or phenolic impregnated carbon
ablator which removed more than 99% of
the kinetic energy of the vehicle and
kept the sample below 75°.
Pika is a type of ablative heat shield
which works by using a protective layer
on the outside of a spacecraft to
safeguard it during re-entry. Because
the spacecraft experiences extreme
friction on its way down through the
atmosphere, it generates immense heat.
As the temperature of the shield heats
up, it burns away its outer layer in a
process called ablation. During this
process, the heat shield melts and
vaporizes, and those gases carry the
heat away from the spacecraft. This
sacrificial shield prevents heat from
reaching the interior of the return
capsule, keeping the asteroid sambble
cool and safe.
A couple of minutes after re-entry, the
capsule decelerated enough to release
the first of two parachutes, which
helped to stabilize it for the remainder
of its trip to the surface. about 16 km
from the ground, radars were able to
lock onto the capsule's location and
track it to within about 10 m of where
it would eventually land. And for the
final kilometer and a half of descent, a
second parachute was deployed to soften
the landing to a leisurely speed of 18
km/h, or about the average speed of a
cyclist on flat ground.
From the moment it pierced Earth's
atmosphere to when the capsule gently
touched down in the rugged desert
landscape of Utah, it took just 10
minutes.
After years of planning, months of
special training, and several
rehearsals, the NASA recovery team moved
in by helicopter to secure the return
capsule and its contents. To ensure the
sample was not exposed to Earth's
environment, the capsule remained closed
until after it had been moved to a clean
room and decontaminated.
But opening the sample canister didn't
quite go according to plan.
Within a couple of weeks, scientists at
NASA's Johnson Space Center in Houston,
Texas, were able to open the outer lid,
revealing 70 g of dark gray rocks and
dust outside of the sample canister.
Apparently, not all that extra material
it had picked up had stayed around.
Still, 70 g was nothing to sniff at. It
was 10 g more than scientists had hoped
to collect in their initial mission
plan. While this bonus material from
Bennu was able to be analyzed and used
in scientific research, it wasn't as
pristine as the material held inside the
inner sample canister. However, it would
take months and the invention of a new
tool before the curation team at the
Johnson Space Center was able to open
the main sample canister to reveal this
pristine material.
The mission was meticulously planned.
So, why did they need to invent a new
tool just to open the canister? And why
did it take so long?
Well, for one thing, the bonus material
slowed down the process of getting into
the inner canister because all of that
extra material had to be carefully
removed, cataloged, and stored. Another
reason this took a long time is because
all of these tedious tasks had to be
done inside of a nitrogen purged glove
box. an enclosed box with built-in
gloves that is constantly flooded with a
flow of neutral nitrogen gas to make
sure the sample does not react with
other gases in Earth's atmosphere like
oxygen or water vapor. While use of this
clean environment was necessary to make
sure the sample remained uncontaminated,
the glove box made a set of already
tedious tasks even more difficult.
But the main slowdown came during
disassembly of the tag sam when two of
the 35 fasteners holding it shut could
not be removed with existing tools. The
two problem screws had been infiltrated
by dust from Bennu, essentially causing
the threads to be stripped. Imagine
having successfully retrieved this
capsule after its arduous journey to
Benu and back just to not be able to
actually open it.
But NASA engineers wouldn't be NASA
engineers if they didn't immediately set
to work to invent what was needed to
crack this nut open. Because the samples
needed to be protected from any
contamination, the new screwdriver-like
tool with custom fabricated bits made
from a specific grade of surgical
non-magnetic stainless steel had to be
designed, fabricated, and tested before
it could be introduced into the pristine
glove box. But all of this time and
effort paid off. 3 and 1/2 months after
the return capsule touched down on
Earth, the creation team was finally
able to access the material inside the
canister using these new tools. Another
51 g of pristine Bennu material was
revealed. And when combined with the
bonus rocks and dust already collected,
the total amounted to more than twice
what the mission had aimed to bring back
to Earth.
The material was then cataloged and
divided into smaller samples. At least
70% of the material will be preserved in
its pristine condition for future
generations to have the opportunity to
study. And from the remaining material,
more than 200 scientists at labs around
the world will have the chance to study
pieces of asteroid Bennu.
Just imagine being able to study a piece
of our solar systems past. A sample
packed with clues about the origins of
life in the early solar system. What
awesome stories could an ancient relic
like Bennu tell. Just over a week after
recovering the return capsule from
Osiris Rex, scientists got their first
look at the bonus asteroid soil sample
called Regalith.
While Bennu might have broken off from a
much larger asteroid 1 or 2 billion
years ago, its present-day chemistry and
minology were already set in stone, so
to speak, more than 4.5 billion years
ago since its composition has remained
relatively unchanged. Bennu contains the
primordial ingredients that were present
before our planets existed. The sample
from Bennu contains what are called
pre-olar grains, which are microscopic
crystals that condensed before our sun
came to be. Depending on the composition
of these pre-olar grains, we can get an
idea for the types of stars that existed
before our own solar system formed. The
higher the mass of a star, the heavier
elements it will be able to fuse
together. For example, small and
intermediate mass stars burn by fusing
light elements like hydrogen into helium
and may eventually fuse heavier elements
such as carbon and nitrogen. Large mass
stars can fuse together even heavier
elements like silicon and iron.
Importantly, these large mass stars can
end their life in a supernova explosion,
creating elements even heavier than
iron.
Because these elements from stellar
fusion get spread across the universe
and recycled to form new stars,
asteroids, and planets, we can learn
about the ancient building blocks of our
own solar system by looking at these
pre-olar grains.
A cosmochemist at the University of
Arizona and member of the Osiris Rex
team said that initial analysis of these
pre-olar grains showed evidence of small
and medium-sized stars, but also of
supernova.
In fact, later study of these grains by
a team at NASA's Johnson Space Center
revealed they contained six times the
amount of supernova dust than any other
astro material that had been studied on
Earth before. This supports the idea
that our solar system was enriched by a
range of different sized stars long
before our solar system formed.
Initial analysis of the asteroid sample
revealed a dust rich in carbon and
nitrogen. But there was more. Recently,
amid the dust of Bennu, scientists found
15 out of the 20 amino acids that all
living things on Earth stem from, as
well as five biological nucleases,
adinine, guanine, cytosine, thymine, and
uricil. the basic components that make
up DNA.
Additionally, a team led by Yoshihiro
Furukawa at Tohoku University in Japan
discovered essential sugars in the
sample from Bennu, including ribos and
for the first time ever, glucose, an
important energy source for life. The
discovery of ribos and not deoxyibbos
indicates that ribos may have been a
more common sugar in the early solar
system supporting the RNA world
hypothesis that the first forms of life
relied on RNA and not DNA to store
information and drive their chemical
processes. Another team at NASA's AS
Research Center discovered a brand new
material never before seen in space
rocks. A space gum made of polymer
materials rich in nitrogen and oxygen.
Shaving the material down to thinner
than a human hair. They used electron
microscopy and X-ray spectroscopy to
study its chemical structure, revealing
this strange substance had been
deposited in layers on grains of ice and
minerals in the asteroid and appeared to
be close to polyurethane in composition.
Although a far more random composition
than the plastic we're used to seeing on
Earth, complex molecules like these may
have provided some of the precursors for
triggering life on Earth. And finding
them on an extraterrestrial asteroid
like Bennu is like gold dust for
scientists studying how life began and
whether it might exist beyond the
reaches of Earth. These delicate,
complex molecular structures represent a
fascinating find, proving that the
building blocks of life were widespread
across the solar system. But they also
showcase the value of this gentler
sample collection strategy. They would
not have survived a fiery atmospheric
re-entry. So, it was only by being
brought here by Osiris that we could
prove the early solar system contained
so many of these vital compounds.
NASA's Osiris Rex science team also once
again found evidence of water in Bennu's
past in the form of waterbearing clay
minerals in the sample. These clay
minerals confirmed what scientists had
previously observed in spectroscopic
surveys of Bennu. As we mentioned
earlier, they indicated that Venu may
have originated from a larger body that
once contained water. But how did these
ingredients of life form on such a
seemingly barren asteroid? And why is
there evidence of water?
As it turns out, these essential
ingredients of life are actually
abundant throughout the universe.
Planetary scientists and astronomers
have identified organic compounds across
our solar system, throughout the Milky
Way galaxy, and even in interstellar
space. We find these compounds in
asteroids and meteorites, on moons, in
nebula across the galaxy and beyond.
All it takes for these simple building
blocks of life to form is a combination
of oxygen, carbon and nitrogen which are
the third, fourth and fifth most
abundant elements in the universe by
number of atoms respectively.
These elements are created inside of
stars and remnants from those ancient
stars are spread across the universe. We
are made of star stuff and from what
we've learned, the stuff of life is
abundant.
But the presence of amino acids and
other organic compounds doesn't mean
that life ever arose in those places. In
fact, with no atmosphere and
temperatures ranging from a frigid 73° C
up to a scorching 116° C, Bennu is not a
very hospitable place for life to have
developed. Rather, the presence of
organic compounds means the building
blocks of life seem to be abundant
throughout the universe. and asteroid
Bennu is further proof.
Astronomer Dr. Carl Sean once compared
the emergence of life to a musical
composition. The organic compounds on
Bennu are like a collection of
unorganized musical notes that do not
yet create the music itself. Still,
finding these molecules in such a
pristine sample from Bennu is exciting,
as these minerals could offer clues
about the chemical reactions that
predate biology.
More intriguingly perhaps is that
planetary scientists like Sarah Russell
at London's Natural History Museum and
an Osiris Rex team member said the
sample is dominated by hydrated
minerals, suggesting that Bennu may have
once been part of a larger body that
harbored water. The sample was packed
with evidence of dynamic transformations
that occurred over time in the presence
of water, like clay minerals or salts
left after water evaporates.
It contained a mineral called serpentine
which mirrors a type of rock that we
find at mid ocean ridges on Earth. These
mid ocean ridges are where molten
material rises up from within Earth's
mantle and encounters water, creating
new crust along the ocean floor. Benu's
regalith also harbored pyotite, an iron
sulfide material that can form near
hydrothermal vents on Earth. And even
more surprisingly, the Osiris Rex team
found phosphates in the sample, an
essential component of DNA and in turn
for life on Earth. The presence of these
water soluble phosphates indicates that
billions of years ago, Bennu may have
been part of a larger water soaked
mudball or even a world with an active
geology and an abundance of organic
compounds.
While there isn't enough evidence yet to
conclude that Bennu came from an ancient
water world, Harold Connelly, a
geologist at Rowan University and Osiris
Rex missing sample scientist, said that
evidence of warm water over time in the
sample does indicate that Benu's parent
body was at least 10 km wide or even
larger.
Although more research is happening in
order to further study these
indications, it's incredible to imagine
that Bennu may have originated from a
much larger asteroid or a protolanet
that shared some important
characteristics with the primitive Earth
or with some of the icy oceancoed moons
across the solar system like Enceladus
or Europa.
So, what else can we learn from the
Bennu samples and what comes next for
the Osiris Rex spacecraft?
The data and samples from Osiris Rex
will keep scientists busy for years to
come as planetary scientists,
geologists, astrobiologists,
chemists, and interdisciplinary research
teams around the world continue to study
this one-of-a-kind sample from Bennu.
And while we have a pretty good
understanding of how the solar system
and our planets formed, this is giving
us the opportunity to calibrate,
confirm, and adjust our current
knowledge and to explore the answers to
new questions that are only possible
because of the Osiris Rex mission. Did
the stellar nebula of dust and gas that
went to form our sun and planets all
come from just one ancient star? Or did
it come from multiple generations of
stars of different star types? Where did
Ben Bennu's parent body form? And what
materials was it made of? And during
Earth's formation and early existence,
did some of its water or organic
compounds come from asteroids?
These are just a few of the long list of
questions that scientists are hoping to
shed light on in the coming years with
the help from the Bennu sample. As for
the spacecraft's missions, they don't
end there. About 20 minutes after
releasing the Bennu sample capsule above
Earth's atmosphere, the Osiris Rex
spacecraft fired its engines to send it
on a new trajectory and a new mission.
Having captured a sample of Bennu, this
Egyptian heron will be off to slay a new
beast, Apopus, the Egyptian serpent of
chaos, destroyer of light and order, or
more accurately, the Apopus asteroid, a
370 m diameter asteroid that is believed
to be passing within 50,000 km of Earth
in 2029.
Let's hope that the asteroid does not
behave in a way that's too in keeping
with its Egyptian namesake. Either way,
Osiris will be heading off to
investigate it. Starting in June 2029,
it will begin an 18-month campaign to
map the asteroid surface, analyze its
chemical makeup, and to observe any
changes that happen to Apotfist during a
near Earth encounter.
Finally, the spacecraft will repeat one
of its most impressive maneuvers from
the mission to Bennu by dipping within
16 ft of the asteroid surface and firing
its thrusters to stir up rocks and dust.
To reflect this extension of the
mission, Osiris has been given a new
name. No longer is it Osiris Rex. It is
now Osiris Apous Explorer or Osiris
Apex. With a name like that, perhaps its
greatest discoveries are yet to come.
So, there you have it. Investigations
are ongoing, but already the initial
analysis of Benu samples have exceeded
our expectations in several ways.
Whether Osiris Rex or Osiris Apex, this
asteroid hopping probe has already
achieved incredible results and executed
a flawless mission. I for one can't wait
to see what other secrets Bennu and
Apopus will reveal.