Guest Blog: Bennu and Some of the Biggest Science Questions of Our Generation

This week, NASA’s OSIRIS-REx science team is meeting as a whole for the last time before the sample of asteroid Bennu arrives on Earth. This occasion marks the last chance for the group to convene to make sure team members, lab facilities, and sample-analysis techniques are working as expected and ready for the delivery of Bennu’s rocks this September.  

In the post below, Jason Dworkin, OSIRIS-REx project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, reflects on the big science questions that inspired this daring mission.

A white person with short, brown hair, wire-rimmed glasses, a smile, and a beard stands in the foreground of this image. This is Jason Dworkin, an astrobiologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Dworkin is the project scientist for NASA's OSIRIS-RE mission. He is visible from the waist up, wearing a dark blue dress shirt and holding up a brown rock with his right hand. The rock is a fragment of the Canyon Diablo meteorite, which struck Earth 50,000 years ago, creating Meteor Crater in Arizona. In the background of the image is Dworkin's lab at NASA Goddard, featuring blocky, metal machines, plus wires and metal tubes handing from the ceiling.
Jason Dworkin is an astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the project scientist for NASA’s OSIRIS-REx mission. He is standing in NASA Goddard’s Astrobiology Analytical Laboratory, where he and other scientists study meteorites, Apollo Moon samples, plus comet and asteroid samples. Dworkin’s lab will receive pieces of asteroid Bennu for study after the sample arrives on Earth on Sept. 24, 2023. In this picture, Dworkin is holding a fragment of the Canyon Diablo meteorite, which struck Earth about 50,000 years ago, creating Meteor Crater in Arizona. Credit: Dennis Drenner.

There are only a few months left until NASA’s OSIRIS-REx delivers a sample of asteroid Bennu on Sept. 24, 2023. It’s feeling more and more real every day. I feel as though I have so much left to do, even though I’ve already spent 19 years preparing for this moment.

When the sample returns, 233 scientists globally, including me, will get to explore the asteroid in our labs. In doing so, we will address dozens of questions about asteroids, the early solar system, and the origins of life. You can see these questions reflected in the full name of the mission and spacecraft: Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer. (I’ll get deeper into the name later.)

I am an astrobiologist at NASA Goddard. I’m also the project scientist for OSIRIS-REx, which means I help manage mission science. My specialization is in the chemistry related to the origins of life, and so I work a lot with space rocks. My team in the Astrobiology Analytical Laboratory studies meteorites, Apollo Moon samples, comet samples from NASA’s Stardust mission, and asteroid samples (we’ve analyzed pieces of Itokawa and Ryugu, asteroids sampled by our partner, JAXA, or the Japanese Aerospace Agency). JAXA is among the many institutions that will get pieces of Bennu.

When our Goddard lab receives the first pieces of Bennu in October 2023, we will analyze them like a forensics lab, including grinding them into dust and subjecting them to boiling water, acid, and more. All this to gain insight into the chemistry of the compounds in the rocks.

This graphic shows a global map of white continents against light blue seas, with lines jutting out from the center, which is in North America. The map helps visualize the global nature of the OSIRIS-REx mission. Each line points to a global destination for pieces of the sample of Bennu. There are 38 lines, all of which start in Houston, Texas, where the sample of Bennu will be stored and curated. Below the global map is a list of the 38 institutions that will be receiving samples for a diversity of scientific investigations.
This graphic shows a global map of destinations for the asteroid Bennu sample, which will arrive on Earth on Sept. 24, 2023. Below the map is a list of the institutions that will be the first to receive samples for a diversity of scientific investigations. The map is centered on Houston, where the sample will be curated and stored for the wider scientific community of today and of the future. Credit: NASA/Goddard/University of Arizona.

Besides my own work and that of my global colleagues, one of the most exciting things for me about the OSIRIS-REx mission is that ¾ of the Bennu sample will be put aside for the global scientific community and for the future. This practice is a legacy from the Apollo missions – we’re still opening and analyzing new caches of Moon rocks brought here by astronauts about 50 years ago! Saving extraterrestrial samples for the future ensures that they can be analyzed by scientists not yet born, using techniques not yet invented, to address questions that were unanswerable when the samples were collected.

We don’t know what questions future scientists will have about asteroids, but here are some of the biggest ones driving the science of this generation:

Does the sample contain organic compounds that could have influenced the origins of life?

This question relates to the Origins, “O,” part of the OSIRIS-REx acronym as it applies to NASA’s search for the origins of life on Earth and possibly elsewhere in the solar system and beyond. All Earth life has specific chemicals, such as amino acids and sugars. We know that asteroids contain the molecular precursors to these chemicals, and we suspect that asteroids may have delivered these precursors to Earth. With Bennu samples, we will analyze the properties of these precursor chemical compounds and try to map out if, and how, these chemicals could have evolved into life.

How does the Bennu sample compare with our interpretation of data collected at the asteroid?

This question is related to the Spectral Interpretation, “SI,” and Resource Identification, “RI,” parts of OSIRIS-REx. We will analyze the mineral and chemical makeup of the samples to see if it aligns with what we expected based on spectral, thermal, and physical data gathered by the spacecraft at the asteroid. Being able to test our interpretation of spacecraft data in this unprecedented way — by comparing data from space to pieces of the physical object — will help us improve future missions and interpretations of telescopic and spacecraft data.

What does the sample tell us about the history of the solar system?

This question relates to the rest of the Origins, “O,” and some of the Security, “S,” parts of OSIRIS-REx. Besides the origins of life, we are also interested in the origin of our solar system. Because we suspect that Bennu could be older than our solar system, we hope the sample will open a window into the earliest time of solar system formation. We are interested in learning more about the condensation of gas and dust that formed the Sun; the formation and destruction of Bennu’s parent asteroid (we think Bennu broke off a larger asteroid during a collision billions of years ago); the formation of Bennu and its migration to the inner solar system, where its orbit will continue inching closer to Earth’s over hundreds of years; and to the formation of the crater on Bennu’s surface where we collected our sample.

How has the sample changed since the spacecraft collected it?

The act of sample collection, the Regolith Explorer, “REx,” part of the mission name, was violent and may have influenced the chemistry of the pieces that are coming home, not to mention their three-year journey between Bennu and our laboratories. Thus, we will study the sample to understand what kinds of physical and chemical changes it experienced to ensure that we can draw accurate conclusions from our laboratory experiments.

Guest Blog: OSIRIS-REx Recovery Team Motto: ‘Practice, Practice, Practice’

By Richard Witherspoon, OSIRIS-REx Ground Recovery Lead, Lockheed Martin

In anticipation of NASA’s OSIRIS-REx asteroid sample delivery this fall, the team held our first round of rehearsals April 17 to April 27. Our goal was to practice retrieving the spacecraft’s sample capsule from a simulated landing site at Lockheed Martin’s campus near Denver.

I am the Lockheed Martin-based ground recovery lead for sample recovery operations and will help guide the team through the real-life retrieval process when the capsule – carrying pristine material gathered from asteroid Bennu – lands on the Department of Defense’s Utah Test and Training Range in the Great Salt Lake Desert on Sept. 24.

A landscape view of nothing but daytime sky, brownish desert, and mountains in the distance. Fluffy clouds hang at the top of the image, just above the mountains, casting a dark shadow over the otherwise sun-lit surface. A dusting of snow covers the desert floor at the foreground of the image. A bush with dry yellow buds stands in foreground, capped by handfuls of snow left over from a melt.
A view from the Department of Defense’s Utah Test and Training Range, where NASA’s sample of asteroid Bennu will land on Sept. 24, 2023. The scene looks west from Wig Mountain towards the Nevada border and the desert basin where the sample capsule will land. Credit: NASA Goddard/Dan Gallagher

When the stakes for science are this high, it’s imperative we get it right. So, we practice! For almost two years, our team — which includes NASA, Lockheed, and University of Arizona — has been busy writing recovery procedures, thinking through every scenario that could happen to the sample capsule as it lands on Earth, and planning how to properly handle each scenario.

This first round of preparations marks a highly anticipated milestone for the OSIRIS-REx mission and our team. We have been planning the sample capsule recovery process for a very long time, and it’s exciting to see it all become real now, as we practice our procedures and work with hardware.

Four people are standing in a muddy field outside of Denver, Colo., surrounded by metal fencing. They're dressed for cold weather and all wearing nylon gloves. They're all focused on an object in the bottom left corner of the image. The object is shaped like a lampshade -- it's a mock sample capsule. One of the team members is standing by themselves in the right hand corner of the image, holding a video camera that's pointed at the rest of the team and capsule.
NASA’s Johnson Space Center curation team practices collecting environmental samples from the ground around the mock sample capsule, located in the bottom left corner, at Lockheed Martin’s campus near Denver. NASA team members pictured (left to right): Rachel Funk, Melissa Rodriguez, Curtis Calva, and Nicole Lunning. Credit: Lockheed Martin.

This was just the first of many upcoming rehearsals; six will take place before September. These are integral activities that teach us things like if a step in the recovery process is missing, or if we need to re-order a procedure, and more. Getting every step right is critical to preserving the pristine nature of the asteroid sample.

These trials also enable us to practice scenarios where everything goes according to plan, as well as ones where sample recovery goes differently than anticipated. This is also why additional rehearsals will be held in the coming months, with each one increasingly mirroring the real thing.

For example, in April, we hand-placed the sample capsule in the field in various positions and had the team practice recovering it. In July, we’ll release the capsule from the back of a truck at the Utah training range to better experience real-life recovery conditions. For the final dress rehearsal in August, we’ll drop the capsule from a helicopter onto a 10-mile (16-kilometer) by 9-mile (14-kilometer) area in Utah and time how long it takes the recovery team to find it and bring it back to the processing location. The faster the better.

At this point, I can really feel the energy starting to radiate across our recovery team, as we look forward to the big moment of return later this year!

The image shows five scientists covered head to toe in white suits, with long robes, and face coverings. One person has his back to the viewer, and is crouching in the left bottom corner. The rest are standing in a circle around a large metallic object, a mock sample capsule. The capsule is on a cart in the middle of the room. Inside this cleanroom everything is white, including the neon lights on the ceiling. The scientists are practicing opening a capsule with asteroid samples in it. The real capsule with samples from asteroid Bennu, is on its way to Earth now.
The clean room team practices disassembling the sample capsule at Lockheed Martin. Team members pictured (clockwise): Mike Kaye (Lockheed Martin), Ryan Paquette (Lockheed Martin), Wayland Connelly (NASA), Nicole Lunning (NASA), and Levi Hanish (Lockheed Martin). Credit: Lockheed Martin.

Right now, we’re spending most of our time working with the curation team from NASA’s Johnson Space Center in Houston to validate communication processes upon retrieval of the asteroid sample in Utah. The curation team will process and store the sample at Johnson, where it will be delivered as soon as possible after landing. But first, as soon as the sample capsule lands in Utah, the curation team will gather dirt, water, and other remnants from around the capsule’s landing site to test and catalog the elements the capsule will have been exposed to. This will help the team discern which particles on the capsule came from Bennu and which were picked up from its Utah desert landing site.

It’s important that the entire team practices together and works things out ahead of time, so we can foster an environment of good situational awareness among everyone actively involved in the recovery.

Though there’s much work still to be done, I’m immensely proud of the meticulous planning and preparation the OSIRIS-REx team has already accomplished. Most all, I’m looking forward to all the ground-breaking knowledge this unique asteroid sample will provide scientists for generations to come.


2020 – 2023: Touchdown! And Goodbye


This week, we have been recapping noteworthy OSIRIS-REx mission events each day so you can catch up on anything you may have missed so far on NASA’s first mission to collect a sample from an asteroid. 

(Post #4 in a series of four) 

At 1:50 p.m. EDT on Oct. 20, 2020, NASA’s OSIRIS-REx spacecraft fired its thrusters to nudge itself out of orbit around Bennu. It extended the shoulder, then elbow, then wrist of its 11-foot (3.35-meter) sampling arm and transited across Bennu while descending about half a mile (805 meters) toward the surface. After about a four-hour autonomous descent to a 26-foot- (8-meter-) wide spot on Bennu, past menacing boulders that could tip the spacecraft or the sample head and thwart the sample grab, OSIRIS-REx contacted the surface. It then fired a burst of nitrogen gas that stirred up dust and rocks, which were captured by the sample-collection head. Finally, OSIRIS-REx fired its thrusters and safely backed away from Bennu, allowing a captivated global audience to breathe a collective sigh of relief.  

Before departing Bennu, OSIRIS-REx conducted one last flyby of the sample site, “Nightingale,” so scientists could see how the spacecraft’s contact with Bennu’s surface altered the site. They saw something astonishing: Even though the spacecraft barely touched the surface, it left a sizeable crater and scattered many rocks. Scientists ran hundreds of computer simulations to understand how this could have happened, given they had expected the spacecraft to leave only a small divot in the surface.  

That’s when they learned that the particles making up Bennu’s exterior are loosely packed and lightly bound to each other, which means they act more like a fluid than a solid. Had it not fired its thrusters to back away immediately after grabbing a sample, OSIRIS-REx would have sunk into Bennu. 

On May 10, 2021, the spacecraft departed Bennu and headed back toward Earth to drop off the sample-return capsule. When it arrives here on Sept. 24, 2023, OSIRIS-REx will release its sample capsule to land on Earth in the Utah desert, but the spacecraft will not land itself. With the sample delivered, the spacecraft will set off on a new mission, OSIRIS-APEX (OSIRIS-APophis Explorer), to explore asteroid Apophis. 

Learn more: 

NASA’s OSIRIS-REx Spacecraft Collects Significant Amount of Asteroid 

NASA’s OSIRIS-REx Spacecraft Heads for Earth with Asteroid Sample 

Surprise – Again! Asteroid Bennu Reveals its Surface is Like a Plastic Ball Pit 

— Lonnie Shekhtman 

2019 – 2020: Choosing a Touchdown Site from a Sea of Hazards 

This week, we are recapping noteworthy OSIRIS-REx mission events each day so you can catch up on anything you may have missed so far in NASA’s first mission to collect a sample from an asteroid.   

(Post #3 in a series of four) 

Pictured here are the four candidate sample collection sites on asteroid Bennu selected by NASA’s OSIRIS-REx mission. Site Nightingale (top left) is located on Bennu’s northern hemisphere. Sites Kingfisher (top right) and Osprey (bottom left) are located on Bennu’s equatorial region. Site Sandpiper (bottom right) is located on Bennu’s southern hemisphere. Nightingale was chosen as the sample collection site. CREDITS: NASA/Goddard/University of Arizona

Given Bennu’s unexpectedly rough terrain, NASA’s OSIRIS-REx team took extra time to evaluate potential sample collection areas. They looked for flat surfaces between numerous rugged boulders. They also looked for regions with fine grains on the surface that the spacecraft could easily ingest. Through their own analyses and a public mapping campaign, the mission team first identified more than 50 sites, whittled those down to 16, and then to the final four candidates. The spacecraft then spent a month investigating each of the four sites and sending home images so scientists could further evaluate them.  

A spot dubbed “Nightingale” by the team, set in a small crater, rose to the top of the list in December 2019. The size of a few parking spaces, Nightingale was the most promising location to meet both safety and sample-availability considerations. But it wasn’t perfect. The area was only about one-tenth the size the mission team had planned for. This put pressure on OSIRIS-REx navigation engineers to program the spacecraft to dodge boulders, such as a building-size one, nicknamed “Mount Doom,” during its 2020 autonomous navigation to a small spot on the surface. 

Learn more: 

NASA Mission Selects Final Four Site Candidates for Asteroid Sample Return 

X Marks the Spot: NASA Selects Site for Asteroid Sample Collection 

Coming up tomorrow: “Touchdown! And Goodbye.” 

  — Lonnie Shekhtman 

2018: Arrival at Bennu — A World Full of Surprises 

This week, we are recapping noteworthy OSIRIS-REx mission events each day so you can catch up on anything you may have missed so far in NASA’s first mission to collect a sample from an asteroid.  

(Post #2 in a series of four)

After traveling 1.2 billion miles (2 billion kilometers) to Bennu, NASA’s OSIRIS-REx spacecraft arrived in December 2018 and began orbiting the asteroid. Until the spacecraft got to Bennu, we could only see the asteroid as a pixelated blob through Earth telescopes and radar measurements. Still, scientists had an idea of what they would find at Bennu by using years of radar and thermal measurements and computer models to predict its mass, shape, and surface features.  

On the left, a compilation of radar images of asteroid Bennu. On the right, a shape model based on radar imaging and visible light curves. CREDITS: Michael C. Nolan / Arecibo Observatory / CC BY-NC-ND 3.0

In early 2019, OSIRIS-REx began to study Bennu in detail. The spacecraft zigzagged Bennu in a trajectory that looked like a child’s sweeping crayon sketch. The first closeup images of the asteroid revealed surprises that would require scientists to update some of the fundamental assumptions used in their predictive computer models.  

Instead of there being a smooth, sandy beach on the surface that the mission team had expected to see, Bennu was littered with boulders and was spewing rock particles into space. It became clear that safely navigating to the surface would be an unexpected challenge. The mission team would spend most of the next year mapping Bennu in detail and looking for a relatively smooth area with the fewest hazards and the most opportunity to gather scientifically interesting samples. 

Learn more:

NASA’s OSIRIS-REx Spacecraft Arrives at Asteroid Bennu 

NASA’s OSIRIS-REx Spacecraft Enters Close Orbit Around Bennu, Breaking Record 

NASA Mission Reveals Asteroid Has Big Surprises 

Coming up tomorrow: “Choosing a Touchdown Site from a Sea of Hazards.” 

 — Lonnie Shekhtman 

2016: NASA’s OSIRIS-REx Launches from Earth

This week, we are recapping noteworthy OSIRIS-REx mission events each day so you can catch up on anything you may have missed so far in NASA’s first mission to collect a sample from an asteroid.  

(Post #1 in a series of four) 

NASA’s first mission to sample an asteroid, OSIRIS-REx, launched on Sept. 8, 2016, at 7:05 p.m. EDT from Cape Canaveral Space Force Station in Florida. About the size of an S.U.V., OSIRIS-REx would travel for two years to a near-Earth asteroid originally designated 1999 RQ36. The name “Bennu,” referencing an ancient Egyptian deity, was picked in 2013 by nine-year-old Michael Puzio, from North Carolina, who won a naming competition.  

NASA chose to go to Bennu because the asteroid possesses several key characteristics that make it perfect for a sample return mission. Here are all the reasons why 

Scientists around the globe have been waiting for years for the spacecraft to deliver a sample from Bennu to Earth. Among the many questions they’ve been waiting to explore by analyzing pieces of Bennu is: Did asteroids deliver molecules that played a role in the origin of life on Earth, and potentially on other planets and moons? 

Learn more: 

NASA’s OSIRIS-REx Speeds Toward Asteroid Rendezvous 

Why Bennu? 10 Reasons 

Coming up tomorrow:Arrival at Bennu — A World Full of Surprises.” 

— Lonnie Shekhtman 

NASA Prepares for Historic Asteroid Sample Delivery on Sept. 24

After seven years in space, including a nail-biting touchdown on Bennu in 2020 to gather up dust and rocks, NASA’s intrepid OSIRIS-REx spacecraft is about to face one of its biggest challenges yet: deliver an asteroid sample to Earth while protecting it from heat, vibrations, and earthly contaminants.   

“Once the sample capsule touches down, our team will be racing against the clock to recover it and get it to the safety of a temporary clean room,” said Mike Moreau, deputy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. 

Learn more here.

Welcome to the OSIRIS-REx Blog


Welcome to the OSIRIS-REx blog. Here you will find updates on NASA’s first mission to collect an asteroid sample for analysis in labs around the globe.

NASA’s OSIRIS-REx spacecraft is cruising back to Earth now with samples it collected at the rocky surface of asteroid Bennu on Oct. 20, 2020. The spacecraft will deliver these samples on Sept. 24, 2023, thereby expanding NASA’s legacy of bold missions to collect extraterrestrial samples of rocks and regolith – missions that started in 1969 when Apollo 11 landed on the Moon’s surface.

We invite you to check back here regularly to learn how NASA is preparing for the sample return event. You’ll learn how the asteroid sample will make it to Earth’s surface and meet the scientists and engineers who will collect the sample capsule in the Utah desert, where it will land. We’ll also give you a behind-the-scenes peek at the extensive rehearsals necessary to transport, open, and store this pristine cache of rocks and dust that can reveal the history of our solar system.  

– The OSIRIS-REx Team

If you want to learn more about the OSIRIS-REx launch in 2016, see the posts below.