{♫Intro♫}
The idea of a Moon colony has been a staple of science fiction since before humans even
started going to space.
But even five decades after the first lunar bootprints, the idea of sustaining astronauts
on the Moon long-term has a lot of challenges.
Like access to water, which is a big deal for sustaining humans.
It is not practical, and it is definitely not cheap to lug water all the way from the
Earth to the moon.
So it would be great to know if the Moon has any water of its own.
And this week in Nature Astronomy, two papers have given us new insight into how much water
the Moon may actually hold.
Now, this desolate, gray world might be the last place you’d expect to find good ‘ol H2O.
But we know that water comes in lots of forms all over space—and they’re not all obvious.
So, scientists suspected it was possible some was hiding out on the Moon.
For instance, water might have gotten carried to the surface on micrometeorites.
Then, it may have either gotten trapped inside the impact sites,
or scattered into the super-thin layer of gas surrounding the Moon.
It might also have formed on the Moon itself from chemical reactions between molecules
containing hydrogen and oxygen.
And back in 2009, an orbiter circling the Moon even found possible evidence of water
ice near the Moon’s south pole.
But scientists weren’t 100% sure if this was really water, or something else with hydrogen
and oxygen that shared a similar chemical fingerprint.
To figure it out, one team used the airborne infrared telescope called SOFIA, which flies
inside a modified Boeing 747.
It observed the Clavius Crater in the Moon’s southern highlands using a slightly longer
wavelength than the 2009 study.
At this wavelength, if there were water, its unique chemical fingerprint should be possible
to distinguish.
And that hunt was successful—astronomers detected water ice in the crater.
It wasn’t much—there was less than a gram of water for every kilogram of other material,
which makes it 100 times drier than the Sahara.
But still, it was something.
The researchers believe the water is trapped within the glassy material that formed during
the high temperatures of a meteorite impact.
Although it’s also possible the water could be packed between grains of lunar dust, which
could shield it from the harsh environment.
Either way, we’re not looking at something that astronauts could chop and put into their
mixed drinks or anything, but they could potentially still harvest it.
And this may not even be the only place there’s water on the Moon.
Astronomers have hypothesized for a while that water could hide out in craters and pockets
that are permanently shadowed, called cold traps.
So in a second study in the same issue of Nature Astronomy, researchers used data from
the Lunar Reconnaissance Orbiter, along with computer modeling, to see how many of these
pockets are out there.
And the answer turns out to be… a lot.
Some of these cold traps are as small as a single centimeter in diameter, but between
those and a bunch of larger ones, researchers estimated that these regions could cover an
area roughly 40,000 square kilometers in size.
That’s roughly as large as Switzerland.
Many of those cold traps are near the poles, where the sunlight’s low angle leaves more
areas permanently in shadow and the temperatures stay cold.
The study didn’t attempt to see how many of these cold traps actually had water, but
it gives us a starting point for estimating how many places water could hide out.
Meanwhile, in other space news, scientists have released their findings from another
exciting discovery here on Earth.
Back in 2018, a 50-kilogram meteoroid burned through the Earth’s atmosphere,
and a few surviving chunks landed in Michigan.
Scientists quickly recovered them, and now, in a study published Tuesday in the journal
Meteoritics & Planetary Science, they’ve shared what this space rock can tell us about
the origins of our solar system.
See, small asteroids and meteoroids are kinda like cosmic time capsules.
They formed along with our solar system roughly four and a half billion years ago.
But unlike planets, which undergo a lot of transformation over time, these rocks are
basically unchanged.
So they retain the memories of what the early solar system looked like.
The problem is, once they smash into Earth, they get exposed to new chemical and physical
processes that begin to destroy their records.
So the quicker you can find a meteorite, the more intact the time capsule will be.
And in this case, scientists got right on it.
In less than two days, they managed to collect six major pieces, and ultimately, they retrieved
a whole kilogram of debris.
Then, they sent samples to a couple of labs for analysis.
The rocks turned out to be a special type of iron-rich stony meteorite called an H4 chondrite.
Chondrites are basically ancient aggregations of tiny rocks that got smushed together.
And thanks to the rapid harvesting, the composition of these samples was still mostly undisturbed.
When scientists examined them, they found tens of thousands of complex organic molecules
hanging out in them—which is exciting.
Organic molecules are the reason we are here—they’re the reason life exists.
But we don’t know for sure where they come from, and one hypothesis is that they were
introduced by meteorites.
So this finding suggests that it’s at least possible that similar rocks could have brought
a whole range of chemicals to our infant Earth to help spark the processes that eventually
led to life.
And it’s kind of incredible that a few shards of burned-up rock can give us a glimpse back
to a time before the Earth as we know it even existed.
Thanks for watching this episode of SciShow Space News!
And a special thanks to all our patrons who make this show possible.
If you want to find out what you can do to help keep SciShow going, you can find out
more at patreon.com/SciShow.
♫Outro♫}