In the fall, a NASA spacecraft named OSIRIS-REx dropped a capsule containing more than 120 grams of space dust into the Utah desert. That material came from Bennu, an asteroid that, a billion years ago, broke off from a bigger world that may have hosted liquid water. Studying this material will clarify the role that asteroids might have played in bringing life’s ingredients to Earth.
For Dante Lauretta, a planetary scientist at the University of Arizona and the mission leader, retrieving the sample spelled the end of an era. Since the mission began in 2016, Lauretta has been immersed in all things OSIRIS-REx. Frames on the wall of his office showcase covers of the journals Nature and Science that featured the journey to Bennu and back. Next to them is an oversize cover of his new book, “The Asteroid Hunter: A Scientist’s Journey to the Dawn of Our Solar System.” Part mission report, part memoir, the book tells the story of how two ancient carbon atoms — one on Bennu, one entangled in the genetic code of Lauretta — find each other again.
After dropping off the sample, the OSIRIS-REx spacecraft continued its voyage through the solar system, and Lauretta handed off the keys. He recently spoke to The New York Times about life after OSIRIS-REx and how the mission’s impact carries on. The following conversation has been edited for brevity and clarity.
Q: What have you been up to since OSIRIS-REx’s final act?
A: The weeks after Earth return were all Houston, all day long. The disassembly of the asteroid sample collector was going slower than we expected, but it was fun and historic. I got to go in the clean room and be there for those moments when we first laid eyes on the sample. By early November, I had some of the sample in my lab in Arizona.
Students in my astrobiology class got lectures live from Johnson Space Center in Houston. I took them around with my phone, and the sample processors came over and danced around in their bunny suits. It was amazing.
(Erika Blumenfeld, Joseph Aebersold | NASA via AP) This photo provided by NASA on Wednesday, Oct. 11, 2023 shows the outside of the Osiris-Rex sample collector with material from asteroid Bennu at middle right. Scientists have found evidence of both carbon and water in initial analysis of this material. The bulk of the sample is located inside.
Q: Why was disassembly taking so long?
A: There were a couple of screws that were stuck, and we didn’t have tools that would keep the sample pristine. Hard tools have carbon steel in them, and we didn’t want those tools in the clean room because of contamination — carbon is of interest for astrobiology and origins of life and all the fun science that we’re doing. So the tools we use are soft. And you could see the screwdriver’s head starting to distort while trying to remove the fasteners.
Eventually, we just decided to go through a flap on the head of the sample collector, and pulled out around 70 grams of stuff. That was already more than we promised NASA we’d bring back. Then we took some time to build a screwdriver we could use, and finally cracked the thing open in January.
Q: Any surprises with the sample so far?
A: In 2020, we wrote a paper about big white veins — like a meter long, 10 centimeters thick — on the rocks and boulders of Bennu. We thought those were carbonates that formed in water, which is exciting. Carbon-bearing minerals are found in biological systems.
When we got the rocks back, some of them had this white, crusty material all over them. I was so excited because I thought we had gotten the carbonates. But when I got some grains in the lab, it was phosphate, a compound that contains the element phosphorus. And it was rich in sodium.
We had a student look at one grain under an electron microscope, and it was cracked and desiccated. It looked like a mud flat after the water evaporates, when it gets all fractured and shrinks up.
So did we get it wrong at the asteroid? I don’t know. Were those veins actually phosphates? We’re still chasing that down.
Q: What would it mean for those veins to be made of phosphorus rather than carbon?
A: Phosphorus has a special place in my heart, because of the astrobiology work I did as a graduate student. It’s one of the “big six” elements of life, along with hydrogen, carbon, nitrogen, oxygen and sulfur. As the least abundant, phosphorus provides important clues into how the element got involved in biology.
I read a paper about sodium-rich phosphates coming out of the plumes of Enceladus, one of Saturn’s moons. And then a study came out about soda lakes in Canada, which are the most phosphate-rich lakes on Earth that we know. And it had exactly the same chemistry.
I don’t know if Bennu is an exact analog, but this kind of fluid chemistry is important. This could be evidence of liquid water evaporating away with high concentrations of phosphorus, a key ingredient for the origin of life. And other groups are finding similar chemistry in biologically important environments, one around Saturn and one on Earth. This is a dream come true.
(Francisco Kjolseth | The Salt Lake Tribune) Dante Lauretta, the OSIRIS-REx principal investigator from the University of Arizona, pumps his fist as his team returns from Utah’s West Desert where they retrieved a capsule containing a sample from the surface of asteroid Bennu on Sunday, Sept. 24, 2023.
Q: How did your book come about?
A: I came up with the idea of writing a more personal version of OSIRIS-REx in 2018, before the mission had even gotten to Bennu. We collected the sample in 2020 and had 2 1/2 years to cruise before it landed on Earth, so I spent those years writing.
The book ends with the sample return in Utah, so the two epilogues weren’t written until the week after. On the flight from Utah to Houston, I put some earbuds in and just narrated everything that had happened over the past 24 hours. And then I wrote the finale of the two carbon atoms, the universal thread that underlies the story, later in my hotel room.
Q: Your book is about OSIRIS-REx, but it’s also about you. How did your childhood prepare you to explore the solar system?
A: I grew up in Arizona, and by the time I was 12, it was just my mom raising three of us. I was much older than my two brothers. We didn’t have a TV. There was nothing but the desert for entertainment. So I spent a lot of time exploring it, finding all kinds of amazing little secrets.
I’d come across Native American structures and petroglyph walls, and really felt a connection in time to those who had come before me. And I started thinking about, well, who came before them? And how far back can you take that question? I remember the first time I found a trilobite — that was amazing. I wondered why it wasn’t around anymore. What happened to it? Could that happen to us?
This is when I started to appreciate geology. There are stories in the rocks. Since then, I’ve always been an explorer. When I got older, I’d go backpacking, camping, on hikes and so on. I just loved going somewhere, and I wanted to go where no one had gone before.
When I did an expedition in Antarctica, I felt like that was it, I’d never get more remote than that. Then OSIRIS-REx came along, and that was just another level — the final frontier.
Q: What’s next for you?
A: I’m the first director of the new Arizona Astrobiology Center. And it is banging! It’s truly a community center, because people are coming to us. Undergraduate students are flocking. Teachers and administrators from K-12 schools want to know how they can get engaged.
I love getting to hang out with students, which I gave up doing a lot of during OSIRIS-REx. It’s very accessible for them to get involved. We can train students and have them on an electron microscope, looking at material from Bennu, in days. Being in this new environment with the student and community focus is wonderful.
I think this is the culmination of what people can do when we unite with a common vision. OSIRIS-REx is so much bigger than me. People tell me how inspiring what we did was, and how proud they are of me, this team and this nation. I feel like I’ve been part of something unbelievable, amazing and powerful.
This article originally appeared in The New York Times.
