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