OSIRIS-REx Bringing Asteroid Samples To Earth - NASA Explains
NASA Planetary Scientist Noah Petro dishes on what it took plan the impressive touch-and-go return mission, why much of the sample will be preserved for future generations of humanity, the best-case scenario for what we find in these rocks — and the worst.
Credit: Space.com | NASA Goddard Space Flight Center
Credit: Space.com | NASA Goddard Space Flight Center
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00:00 NASA sent a spacecraft toward an asteroid named Bennu with the goal of collecting samples
00:06 from the space rock without actually landing on it.
00:09 In 2020, that sample collection happened, quite dramatically I might add, and in just
00:15 a few days the spacecraft is returning to Earth, sample in hand.
00:19 And so we're very excited about the OSIRIS-REx mission and today we have NASA expert Noah
00:25 Petra here with us to discuss the ends and outs of the mission and you know what this
00:28 endeavor might mean for the future of space studies.
00:32 Thank you for joining us Noah.
00:33 Oh my pleasure, thank you for having me, what an exciting time.
00:36 Oh of course.
00:37 And so to begin, I guess the question everyone has is, you know we've collected moon rocks
00:41 and we're looking at Mars sample return, well what can we learn from asteroid sample collection
00:46 that we can't with planetary or moon samples?
00:49 Well the first thing is really that we think, we think that asteroids reflect the very earliest
00:55 parts of our solar system's history, that they are effectively pristine fragments left
01:01 over from the first few hundred million years of solar system evolution and as such, as
01:06 they hurtle through space, remain relatively unchanged.
01:10 And so what we hope to learn through the samples from Bennu is what this particular type of
01:15 asteroid, this carbon-rich asteroid, how it reflects what happened four and a half billion
01:19 years ago and compare it to what we learned from samples from Apollo, through other meteorite
01:25 and asteroid sample studies and really, you know again, use this to inform how we construct
01:30 the family tree that is our solar system and maybe challenge some assumptions that we've
01:35 had, change our interpretations of early solar system history and then guide us on future
01:41 studies of our solar system.
01:43 Yeah, absolutely.
01:44 And more specifically, why was Bennu selected as the asteroid for this project and I guess
01:50 in particular, why was the northern crater from which the sample was collected, why was
01:54 that the site?
01:56 So for multiple reasons, Bennu was an excellent target.
01:59 One, it's a near-Earth asteroid.
02:01 It will pass close to the Earth in the future.
02:03 So we want to understand what these potentially future Earth-intercepting asteroids are like.
02:08 And so by going and studying it, orbiting and mapping the asteroid, we get a greater
02:14 insight into the properties of this wonderful rock in space.
02:19 Collecting the samples, again these carbon-rich samples, may inform our understanding of what
02:23 were the things that seeded Earth with the chemistry that led to life.
02:28 There's a possibility that we'll find amino acids, chemistries within these rock fragments
02:34 that may have helped introduce the compounds that lead to multicellular life on the Earth.
02:42 The other thing is again, understanding how these samples relate to fragments from other
02:48 asteroids that have been brought back by the Japanese Space Agency from meteorites.
02:53 For me, one of the exciting things is by shepherding these materials through the Earth's atmosphere
02:57 in the sample return container, we're able to understand how different pristine samples
03:02 are from those meteorites that we've been studying for well over 50 years.
03:06 And so the encapsulation and preservation of those fragments from the surface of Bennu
03:12 will help us understand meteorite history, whether it's from Bennu or other objects that
03:18 reside in our labs.
03:19 Now, the interesting thing about the spot that these samples were collected from goes
03:24 back to our interpretations of the Earth-based data that we had of Bennu before OSIRIS-REx
03:29 was launched.
03:30 It was assumed that the surface of Bennu would be relatively beach-like, very fine-grained
03:35 material covering the entire surface.
03:37 Of course, when we get there, we see that the surface of Bennu is covered in rocks.
03:41 Almost every inch of the surface has a rock fragment.
03:44 I'm holding a small piece from my personal collection of a rock fragment.
03:49 The entire surface was covered in these rocks.
03:51 And so the spot that we ended up collecting these samples from is one of the few places
03:56 that was not completely covered by rocks.
03:59 And so the fascinating thing will be understanding what we got and how the samples we collected
04:05 relate to other parts of the asteroid.
04:07 And again, we have this wonderful collection of data from the orbital phase of the mission.
04:12 Understanding what we have compared to what we think exists elsewhere on the asteroid
04:16 is going to be, I think, a very exciting field of study as we unlock these samples.
04:21 Yeah, absolutely.
04:22 One of the most interesting things about the sample collection to me was when the spacecraft
04:27 reached out and it went sort of poof instead of, you know, having like a solid surface
04:30 as we might expect with an asteroid.
04:33 Was there any reason that you, that the team decided to not land and actually just do a
04:39 touch and go?
04:40 Yeah, I mean, the idea that a touch and go was baked into the mission from its, you know,
04:46 from its very earliest stages, because, you know, to actually stop the spacecraft and
04:51 touch for more than a few seconds, it's fuel and time.
04:55 So this idea that we touch and go to make it this cosmic kiss really simplifies things.
05:02 You know, as we touch the spacecraft, there's a blast of gas to kick up material that then
05:06 gets collected into the sample collection system and we leave.
05:12 The assumption was, and again, remember Bennu is a very small object, so it's a microgravity
05:17 environment.
05:18 So there was a thought that when we touched the surface of Bennu, they would kick up abundant
05:23 dust so that it could become this dust cloud around the spacecraft.
05:26 So we wanted to get the spacecraft away from this dust cloud as quickly as possible.
05:31 So through this touch and go, we minimize the chance for contaminating the entire spacecraft,
05:36 but maximize the opportunity for collecting these precious fragments that will be returning
05:40 to Earth on Sunday.
05:41 Yeah, absolutely.
05:43 And one of the things that I was really awestruck by is reading about how, like what it took,
05:48 like the maneuvers it took to bring this spacecraft, not just back to Earth, but to a very specific
05:53 spot in Utah.
05:54 So what does it take to accomplish such a feat?
05:58 It takes practice, high level math, engineering, but also an understanding of exactly where
06:03 the spacecraft is in the solar system.
06:04 So this is one of the wonderful things about tracking spacecraft is we know where OSIRIS-REx
06:11 is within a few meters of its location as it hurdles towards the Earth, and it will
06:16 drop off the sample return canister.
06:19 And that sample return canister has to find a particular spot above the Earth.
06:24 Parachutes have to deploy and it will gently touch down in the Utah desert.
06:28 This takes a team of people.
06:30 I hope people don't think that missions are one or two folks locked in an office somewhere
06:36 punching numbers.
06:37 This takes expertise across NASA and really around the world.
06:41 This is a global effort to return these fragments to us here on Earth.
06:46 And we've had an opportunity to do this type of thing before.
06:51 There was the Genesis sample return mission from many, many decades ago that was effectively
06:57 a test run for this.
06:59 So as much as everything is new with OSIRIS-REx, we've learned from previous missions how
07:03 to do this.
07:04 So we have great confidence that come Sunday morning, we'll all be glued to our televisions
07:09 and see parachutes deploy and a gently rocking spacecraft touchdown in the Utah desert and
07:15 make its way to the Johnson Space Center where those samples can be curated so that not only
07:20 scientists today, but scientists for decades and centuries to come can benefit from the
07:25 samples that come back from asteroid Bennu.
07:28 I'm certainly very excited.
07:29 I know the whole space.com team is.
07:31 We've been covering it very, very detailedly.
07:33 Detailedly, I don't know if that's a word.
07:36 It is today.
07:37 It is today.
07:38 On something you said about how these samples will be used for generations to come or studied
07:43 for generations to come, I was really impressed by one of the points in the mission overview
07:48 which said that 70% of the sample is going to be preserved at, I believe, Johnson Space
07:52 Center.
07:53 And I wrote the quote down because I really loved it.
07:56 It was for a study by scientists not yet born using technologies not yet invented.
08:02 So what do you think is the importance of that approach?
08:04 And if you can think of any, what are some gaps that we currently have in these studies
08:09 that like future technologies can help fill?
08:12 The valuable lesson comes from Apollo, Apollo samples, because we learned in 2008 that by
08:17 studying previously studied samples, we could find water in them because we had instrumentation
08:22 that could measure smaller fragments.
08:24 And so the valuable thing for OSIRIS-REx is to preserve everything from fragments the
08:28 size of a walnut down to things that are microscopic because future studies of those microscopic
08:34 samples will find things that we miss in the next years to come.
08:38 So the study of smaller and smaller fragments, I think, is where the bonanza will be because
08:42 we expect that there's going to be many, many microscopic samples that we'll have.
08:46 And so my children and their children and then their children's children will develop
08:50 those technologies and unlock the secrets that are held in those tiniest of fragments.
08:55 Absolutely.
08:56 And just the second part of my question was sort of, you know, what are there any gaps
09:00 that we currently have when studying these types of samples that you know of that you
09:04 hope will be filled with future technologies?
09:06 You know, I don't know.
09:07 I mean, that's the joy is that I think the questions that we want to ask haven't even
09:11 been raised yet.
09:12 Right.
09:13 So so for me, it's perhaps about what might have you know, where in the solar system to
09:16 those fragments form.
09:18 And so on extracting every piece of atomic information from them using technologies that
09:24 have not yet been developed to answer questions that that actually might get raised by other
09:28 sample return missions.
09:29 We're going to be surprised by Artemis.
09:30 We're going to be surprised by bringing in fragments from across the solar system.
09:33 And so those missions will help inform things that we ask of OSIRIS-REx.
09:37 And we know that we'll be surprised.
09:39 And so for me, the joy is finding out where the surprises come from that lead to future
09:44 questions.
09:45 Definitely.
09:46 And I guess sort of related, I think a lot of a lot of the time, the public questions,
09:52 whether it's worth, you know, funneling money into space missions in general and more specifically,
09:57 very science forward space missions like OSIRIS-REx.
10:00 What would you say in response to that?
10:01 Why is this important for humanity?
10:03 Again, I think it becomes, again, the fodder for future science.
10:08 And in my limited amount of time that I have left, I want to say, you know, we've learned
10:12 that missions not only fulfill science questions today, but then allow us to raise and answer
10:17 other questions.
10:18 We have data from Bennu.
10:20 We have the samples.
10:21 And those are going to be used for decades to come, centuries to come.
10:25 And so, yes, it takes money.
10:28 But those fund scientists to ask important questions, to educate the public, and then
10:32 hopefully inform people and excite people to become the future scientists.
10:36 I'm hoping that the kids that watch the sample come back on Sunday will be those future researchers
10:41 who are in laboratories around the globe studying those fragments and unlocking the history
10:46 of the solar system.
10:47 Wonderful.
10:48 I know you have to leave soon, but I guess I'll just leave you with one final question
10:52 on a very personal, like in your opinion, what would be the best thing we find from
10:57 these samples and what would be the worst, do you think?
11:00 I mean, I think that the best thing that we'll find are fragments of potential water, of
11:06 amino acids that may have been the precursors to seeding life here on the planet, as well
11:10 as the ages of these samples.
11:12 How old are they?
11:13 Are they 4.8 billion years old?
11:15 Are they 4.4 billion years old?
11:16 Are they 3.8 billion years old?
11:18 Bennu will hold secrets.
11:20 Some of them will surprise us.
11:21 And that's what I'm most excited about.
11:23 I think the worst case scenario is that we get a suitcase and all of the rocks are very
11:28 similar.
11:29 I'm looking for the diversity of fragments as well, because we know that there are different
11:32 types of material on Bennu.
11:33 And I expect that these samples will all reflect the diversity of that asteroid and have other
11:39 surprises as well, other fragments of other asteroids that have found their way onto the
11:42 surface.
11:43 But even said, if everything is identical, you will then have material that is the feedstock
11:50 for future scientists and for understanding this earliest history of the solar system.
11:54 Wonderful.
11:55 Thank you so much for your time, Noah.
11:56 This was really insightful and I really enjoy our conversation.
11:59 My pleasure.
12:00 Anytime and enjoy the show on Sunday.
12:02 [Music]