Last fall, a NASA spacecraft called 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 broke away a billion years ago from a larger world that may have contained liquid water. Studying this material will clarify the role asteroids may have played in bringing the ingredients for life to Earth.

For Dante Lauretta, a planetary scientist at the University of Arizona and the mission leader, retrieving the sample marked the end of an era. Since the mission began in 2016, Dr. Lauretta immersed in everything related to OSIRIS-REx. Frames on the wall of his office show covers of the journals Nature and Science describing the journey to Bennu and back. Next to it is an oversized 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 Dr. Lauretta – finding each other again.

After delivering the sample, the OSIRIS-REx spacecraft continued its journey through the solar systemand Dr. Lauretta handed over the keys. He recently spoke with The New York Times about life after OSIRIS-REx and how the mission’s impact continues. The following conversation has been edited for brevity and clarity.

What have you been up to since the final act of OSIRIS-REx?

The weeks after returning from Earth were all Houston, all day. The disassembly of the asteroid sample collector was slower than we expected, but it was fun and historic. I was allowed to go to the cleanroom and be there when we first saw the sample. In early November I had part of the sample in my laboratory in Arizona.

Students in my astrobiology class received live lectures from the Johnson Space Center in Houston. I took them with my phone, and the sample processors came over and danced around in their bunny suits. It was amazing.

Why did the disassembly take so long?

There were a few screws stuck and we had no tools to keep the sample pristine. Hard tools contain carbon steel, and we didn’t want those tools in the cleanroom because of the contamination. Carbon is important to astrobiology, the origin of life, and all the fun science we do. So the tools we use are soft. And you could see the head of the screwdriver starting to deform as it tried to remove the fasteners.

In the end we decided to just go through a flap on the head of the sample collector and get about 70 grams of stuff out. That was already more than we promised NASA would bring back. Then we spent some time building a screwdriver that we could use, and finally cracked the thing open in January.

Are there any surprises with the monster so far?

In 2020 we wrote one paper across large white veins – about a meter long and 10 centimeters thick – on the rocks and boulders of Bennu. We thought these were carbonates that formed in water, which is exciting. Carbonaceous minerals are found in biological systems.

When we got the stones back, some of the stones had white, crusty material all over them. I was so excited because I thought we had gotten the carbonates. But when I got some grains into the lab, they were phosphate, a compound containing the element phosphorus. And it was high in sodium.

We had a student look at one grain under an electron microscope, and it was cracked and dried out. After the water evaporates, it looks like a mudflat, when it completely cracks and shrinks.

Did we get the asteroid wrong? Don’t know. Were those veins actually phosphates? We are still working on that.

What would it mean if those veins were made of phosphorus instead of carbon?

Phosphorus has a special place in my heart because of the astrobiology work I did as a graduate student. It is one of the “big six” elements of life, along with hydrogen, carbon, nitrogen, oxygen and sulfur. Because phosphorus is the least abundant, it provides important clues about how the element became involved in biology.

I read one paper about sodium-rich phosphates coming from the plumes of Enceladus, one of Saturn’s moons. And then one study came out about soda lakes in Canada, the most phosphate-rich lakes known on earth. 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 that liquid water evaporates 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.

How did your book come about?

In 2018 I came up with the idea to write a more personalized version of OSIRIS-REx, even before the mission had reached Bennu. We collected the sample in 2020 and had two and a half years before it landed on Earth, so I spent those years writing.

The book ends with the return of the example in Utah, so the two epilogues were not written until the following week. On the flight from Utah to Houston, I put in a pair of earbuds and recounted everything that had happened in the past 24 hours. And then I wrote the finale of The Two Carbons, the universal thread underlying the story, later in my hotel room.

Your book is about OSIRIS-REx, but also about you. How did your childhood prepare you for exploring the solar system?

I grew up in Arizona, and by the time I was twelve, it was just my mother raising the three of us. I was much older than my two brothers. We had no television. There was nothing but the desert for entertainment. So I spent a lot of time exploring it, discovering all kinds of amazing little secrets.

I had come across Native American structures and petroglyph walls and truly felt a connection in time with those who had come before me. And I started thinking about: who was there before them? And how far back can you take that question? I remember the first time I found a trilobite – it was amazing. I wondered why it wasn’t there anymore. What happened to it? Could that happen to us?

Then I started to appreciate geology. There are stories in the rocks. Since then I have always been an explorer. As I got older I went backpacking, camping, hiking 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 would never get further remote than that. Then came OSIRIS-REx, and that was just another level: the final frontier.

What’s next for you?

I am the first director of the new one Arizona Astrobiology Center. And it’s a blast! It really is a community center because people come to us. The bachelor students are arriving. Primary school teachers and administrators want to know how they can get involved.

I love interacting with students, which I did a lot of during OSIRIS-REx. It is very accessible for them to participate. We can train students within a few days and have them look at material from Bennu on an electron microscope. It’s great to be in this new environment that puts the student and community first.

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’m part of something incredible, amazing and powerful.

In 2022, when NASA’s $325 million spacecraft crashed into an asteroid called Dimorphos at 14,000 miles per hour, Earth once again erupted in cheers and applause.

NASA’s Double Asteroid Redirection Test (DART) mission deliberately targeted Dimorphos to change its orbit around the larger asteroid Didymos as a sort of dress rehearsal for thwarting a deadly space rock that could one day be heading towards Earth.

The world’s first ever planetary defense experiment was considered a triumph: the asteroid’s orbit shrank by 33 minutes, well above the minimum threshold of 73 seconds.

But what the DART team didn’t realize at the time was how bizarrely Dimorphos reacted to that blow. a new studypublished Monday in Nature Astronomy, has concluded that DART hit Dimorphos so hard that the asteroid changed shape.

Simulations of the impact suggest that the spacecraft’s death did not excavate a normal, bowl-shaped crater. Instead, it left something that looks like a dent. And although the artificial impact blasted millions of tons of rock into space, much of it splashed back onto the sides like huge tidal waves. It widened Dimorphos, transforming it from a squat ball into a flat-topped oval, like an M&M candy.

The fact that the asteroid behaved like a liquid is due to its peculiar composition. It’s not a solid, continuous rock, but more of a “pile of sand,” he said Sabina Raducan, a planetary scientist at the University of Bern in Switzerland and lead author of the study. And a low-density asteroid barely held together by its own gravity would never react in a simple way if a spacecraft the size of a van flew into its face.

Dimorphos’ response is “completely outside the realm of physics as we understand it in our daily lives,” he said Christina Thomas, the leader of the mission’s observational working group at Northern Arizona University, who was not involved in the study. And “this has overarching implications for planetary defense.”

DART showed that a small spacecraft can deflect an asteroid. But the study indicates that crashing a similarly disjointed space rock too forcefully risks fragmenting it, which in a true asteroid emergency could create multiple Earth-bound asteroids.

Planetary defense clearly works as a concept. “We know we can do it,” he said Federica Spoto, an asteroid dynamics researcher at the Center for Astrophysics, Harvard and Smithsonian, who was not involved in the new study. “But we have to do it right.”

Dimorphos was chosen as a target for DART for numerous reasons. One of the most important was its size: at 170 meters across, it is just the right size of a common variant of a stony asteroid that could easily destroy a city.

Because it is so small and therefore difficult to observe from Earth, little was known about Dimorphos before DART glimpsed it up close during the spacecraft’s terminal approach. But many scientists suspected it was a pile of rubble, a collection of closely spaced boulders.

The handful of space missions that have visited asteroids of similar size – even those with different geological compositions – also showed no correlation. This makes them behave strangely. For example, when NASA’s OSIRIS-REx spacecraft briefly touched down on the surface of the debris-like asteroid Bennu to steal a sample, it sank almost completely into it, as if it were dump into a plastic ball pit.

That DART’s collision knocked Dimorphos back so clearly demonstrated that deflecting these types of asteroids can be successful, even if their properties are largely unknown beforehand.

But early observations made by ground-based telescopes, space-based observatories, and the LICIACube (a small satellite that rode with the DART spacecraft) hinted that Dimorphos responded to this act of interplanetary vandalism with unexpected drama.

“A lot An amount of material was thrown away,” said Dr. Thomas. Dimorphos was quickly enveloped by one swarm of boulders and was followed by a 20,000-mile-long comet-like tail that lasted for months.

What other surprises does Dimorphos have in store? HeraA European Space Agency mission will launch in October and arrive in Dimorphos in late 2026 to explore the asteroid wreckage.

But Dr. Raducan was impatient and decided instead to predict what Hera might discover. Her team ran simulations of the impact, hoping to see which virtual outcome best fit Dimorphos’ fleeting observations after the impact. The lack of a classic crater and a transformed asteroid is not what most astronomers expected.

Like his previously explored asteroid siblings, Dimorphos reacted in an unexpected way when angrily prodded by a robot. That means if the world needs saving from an incoming mess, no assumptions can be made.

“We need more space missions to asteroids,” said Dr. Raducan. “Just because we hit one asteroid doesn’t mean they will all behave the same.”

In 2022, when NASA’s $325 million spacecraft crashed into an asteroid called Dimorphos at 14,000 miles per hour, Earth once again erupted in cheers and applause.

NASA’s Double Asteroid Redirection Test (DART) mission deliberately targeted Dimorphos to change its orbit around the larger asteroid Didymos as a sort of dress rehearsal for thwarting a deadly space rock that could one day be heading towards Earth.

The world’s first ever planetary defense experiment was considered a triumph: the asteroid’s orbit shrank by 33 minutes, well above the minimum threshold of 73 seconds.

But what the DART team didn’t realize at the time was how bizarrely Dimorphos reacted to that blow. a new studypublished Monday in Nature Astronomy, has concluded that DART hit Dimorphos so hard that the asteroid changed shape.

Simulations of the impact suggest that the spacecraft’s death did not excavate a normal, bowl-shaped crater. Instead, it left something that looks like a dent. And although the artificial impact blasted millions of tons of rock into space, much of it splashed back onto the sides like huge tidal waves. It widened Dimorphos, transforming it from a squat ball into a flat-topped oval, like an M&M candy.

The fact that the asteroid behaved like a liquid is due to its peculiar composition. It’s not a solid, continuous rock, but more of a “pile of sand,” he said Sabina Raducan, a planetary scientist at the University of Bern in Switzerland and lead author of the study. And a low-density asteroid barely held together by its own gravity would never react in a simple way if a spacecraft the size of a van flew into its face.

Dimorphos’ response is “completely outside the realm of physics as we understand it in our daily lives,” he said Christina Thomas, the leader of the mission’s observational working group at Northern Arizona University, who was not involved in the study. And “this has overarching implications for planetary defense.”

DART showed that a small spacecraft can deflect an asteroid. But the study indicates that crashing a similarly disjointed space rock too forcefully risks fragmenting it, which in a true asteroid emergency could create multiple Earth-bound asteroids.

Planetary defense clearly works as a concept. “We know we can do it,” he said Federica Spoto, an asteroid dynamics researcher at the Center for Astrophysics, Harvard and Smithsonian, who was not involved in the new study. “But we have to do it right.”

Dimorphos was chosen as a target for DART for numerous reasons. One of the most important was its size: at 170 meters across, it is just the right size of a common variant of a stony asteroid that could easily destroy a city.

Because it is so small and therefore difficult to observe from Earth, little was known about Dimorphos before DART glimpsed it up close during the spacecraft’s terminal approach. But many scientists suspected it was a pile of rubble, a collection of closely spaced boulders.

The handful of space missions that have visited asteroids of similar size – even those with different geological compositions – also showed no correlation. This makes them behave strangely. For example, when NASA’s OSIRIS-REx spacecraft briefly touched down on the surface of the debris-like asteroid Bennu to steal a sample, it sank almost completely into it, as if it were dump into a plastic ball pit.

That DART’s collision knocked Dimorphos back so significantly demonstrated that deflecting these types of asteroids can succeed even if their properties are largely unknown beforehand.

But early observations made by ground-based telescopes, space-based observatories, and the LICIACube (a small satellite that rode with the DART spacecraft) hinted that Dimorphos responded to this act of interplanetary vandalism with unexpected drama.

“A lot An amount of material was thrown away,” said Dr. Thomas. Dimorphos was quickly enveloped by one swarm of boulders and was followed by a 20,000-mile-long comet-like tail that lasted for months.

What other surprises does Dimorphos have in store? HeraA European Space Agency mission will launch in October and arrive in Dimorphos in late 2026 to explore the asteroid wreckage.

But Dr. Raducan was impatient and decided instead to predict what Hera might discover. Her team ran simulations of the impact, hoping to see which virtual outcome best fit Dimorphos’ fleeting observations after the impact. The lack of a classic crater and a transformed asteroid is not what most astronomers expected.

Like his previously explored asteroid siblings, Dimorphos reacted in an unexpected way when angrily prodded by a robot. That means if the world needs saving from an incoming mess, no assumptions can be made.

“We need more space missions to asteroids,” said Dr. Raducan. “Just because we hit one asteroid doesn’t mean they will all behave the same.”

Sixty-six million years ago, an asteroid crashed into the Gulf of Mexico. The catastrophe led to the extinction of as many as three-quarters of all species on Earth, including dinosaurs such as Tyrannosaurus rex. But some flying feathered dinosaurs survived and eventually evolved into the more than 10,000 species of birds alive today, including hummingbirds, condors, parrots and owls.

Based on the fossil record, paleontologists have long argued that the asteroid impact was followed by a major wave of bird evolution. The mass extinction of other animals may have eliminated much competition for the birds, giving them the opportunity to evolve into the remarkable diversity of species that fly around us today.

But one new study about the DNA of 124 bird species challenges that idea. An international team of scientists found that birds began diversifying tens of millions of years before the fateful collision, indicating that the asteroid did not have a major effect on bird evolution.

“I imagine this will ruffle a few feathers,” said Scott Edwards, an evolutionary biologist at Harvard and one of the study's authors. The research was published Monday in the Proceedings of the National Academy of Sciences.

Dinosaurs evolved primitive feathers at least 200 million years ago, not for flight, but most likely for insulation or as a mating display. In one lineage of small bipedal dinosaurs, those feathers became more complex, eventually taking the creatures into the air like birds. There is still debate about how feathers turned into wings for flight. But once birds evolved, they diversified into a variety of forms, of which there are many became extinct when the asteroid plunged Earth into a years-long winter.

In searching for fossils of the major groups of birds alive today, scientists have found these almost none that formed before the asteroid hit. That conspicuous absence has led to a theory that the mass extinction cleared the evolutionary arena for birds, allowing them to explode into many new forms.

But the new study came to a very different conclusion.

“We found that this catastrophe had no impact on modern birds,” said Shaoyuan Wu, an evolutionary biologist at Jiangsu Normal University in Xuzhou, China.

Dr. Wu and his colleagues used the birds' DNA to reconstruct a family tree showing how the major groups were related. The oldest split created two genera, one including today's ostriches and emus, and the other including the rest of all living birds.

The scientists then estimated when the branches split into new lineages by comparing the mutations that accumulated along the branches. The older the split between two branches, the more mutations each line accrued.

The team included paleontologists who helped refine the genetic estimates by examining the ages of 19 bird fossils. If a branch turned out to be newer than the fossil that belonged to it, they adjusted the computer model that estimated the pace of bird evolution.

Michael Pittman, a paleontologist at the Chinese University of Hong Kong who was not involved in the new research, said it was particularly notable because of the fossil analysis. “They had a dream team of paleontologists,” he said.

The study found that living birds shared a common ancestor that lived 130 million years ago. New branches of its family tree branched off steadily throughout the Cretaceous and at a fairly steady pace thereafter, both before and after the asteroid impact. Dr. Wu said this steady trend may have been fueled by the growing diversity of flowering plants and insects over the same period.

Jacob Berv, an evolutionary biologist at the University of Michigan who was not involved in the study, said it illustrates state-of-the-art methods for processing vast amounts of genetic data to reconstruct evolutionary history. But he disagreed with its conclusion.

If the new study was right, there should be fossils of all major groups of living birds from well before the asteroid impact. But hardly anyone has been found.

“The signal from the fossil record is not ambiguous,” said Dr. Berv.

Dr. Berv suspects that the correct story comes from the fossils, and that most major groups of birds emerged after the asteroid impact. The problem with the new study, he said, is that it assumes the bird's DNA accumulated mutations at a steady pace from generation to generation.

But the devastation of the asteroid impact – which collapsed forests and caused a shortage of prey – could have led to the deaths of larger birds, while smaller birds survived. Small birds take less time to reproduce, and they would produce many more generations – and many more mutations – than birds before the impact. If scientists ignore this kind of mutational overdrive, they will misinterpret the timing of evolution.

Still, Dr. acknowledged. Berv that scientists are just beginning to develop methods that can better estimate the rate of evolution and integrate it with other evidence such as DNA and fossils. “I suspect this will settle some debates,” he said.

For generations, Western space missions have largely taken place in the open air. We knew where they were going, why they were going there and what they planned to do. But the world is on the eve of a new era in which private interests transcend this openness, with potentially a lot of money at stake.

Sometime in the next year, a spacecraft from AstroForge, a US asteroid mining company, may be launched on a mission to a rocky object near Earth’s orbit. If successful, it will be the first fully commercial space mission beyond the moon. However, AstroForge is keeping its target asteroid a secret.

The secret space rock mission is the latest in an emerging trend that astronomers and other experts don’t welcome: commercial space missions conducted in secret. Such missions reveal gaps in the regulation of space travel, as well as concerns about whether exploring the cosmos will continue to benefit all of humanity.

“I’m absolutely not in favor of things wandering around in the inner solar system without anyone knowing where they are,” said Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Massachusetts. “It seems like a bad precedent to set.”

But for AstroForge, the math is simple: If the destination is revealed, a competitor can grab the asteroid’s valuable metals for itself.

“Announcing which asteroid we are targeting carries the risk that another entity could seize that asteroid,” said Matt Gialich, CEO of AstroForge.

Asteroid mining hit the doldrums in recent years after two startups proposing to explore the solar system went bankrupt in late 2010. But now several companies in the United States, Europe and China are making a new attempt. Even a congressional committee held a hearing on the subject in December.

The renaissance is being fueled by a new wave of commercial space exploration, driven in large part by SpaceX, the Elon Musk-founded company that flies reusable rocket boosters and has lowered the cost of reaching space.

With this increased activity, secrecy also increases.

In 2019, the Israeli-built commercial Beresheet lander attempted to land on the moon but crash-landed. On board, kept secret until after the failed landing, were a few thousand tardigrades, microscopic animals provided by the nonprofit Arch Mission Foundation. The crash raised concerns about the moon’s possible contamination with the savory creatures and led to an investigation by the Federal Aviation Administration.

More recently, the suborbital spaceflight company Virgin Galactic has concealed the identities of the people aboard the spaceplane until after the missions are completed, a practice not previously seen in human spaceflight. And some satellites hitchhike into space with many other spacecraft, in what is known as rideshare missionsare also kept secret.

“We regularly see launches where we don’t know which satellites have been deployed until some time afterwards,” says Dr. McDowell, who claims a public database of spacecraft in orbit.

For missions beyond Earth, there are no legal restrictions against keeping a deep space mission’s destination secret, as AstroForge plans to do, said Michelle Hanlon, a law professor specializing in space travel at the University of Mississippi.

“We don’t have an actual process for these types of missions in space,” she said, because “there is no licensing process in the United States.”

But complex problems can arise if, for example, multiple asteroid miners arrive at the same asteroid.

“There has to be some kind of transparency here,” said Dr. McDowell. He noted that while there was a requirement by the United Nations for space agencies and companies to disclose their orbits and trajectories in space, “this requirement is mostly ignored for objects in solar orbit.”

The lack of sanctions, he added, “should spark discussion among regulators.”

AstroForge’s mission, Odin, would be the second spacecraft it has sent into space. The first in April, Brokkr-1, was a microwave-sized machine that weighed about 25 pounds. The purpose of that mission was to practice refining metals in space. However, the spacecraft has encountered problems at the company said on December 11. AstroForge is in a ‘race against time’ to get Brokkr-1 working before it is lost.

Odin, on the other hand, weighs a much heavier 220 pounds. AstroForge plans to hitch a ride on a robotic mission to the moon in 2024 from the company Intuitive Machines, which will be sponsored by NASA and launched on a SpaceX Falcon 9 rocket. A launch date has not yet been set.

During the journey to the moon, the intention is for Odin to be released and venture into deep space beyond the orbit of the moon. According to AstroForge, the spacecraft will fly past the mysterious asteroid within a year, taking photos and looking for evidence of metal.

AstroForge is targeting what is believed to be an M-type asteroid. These are believed to be fragmented pieces of failed planetary cores and may be rich in valuable platinum group metals, which have a wide range of applications also in healthcare and jewelry.

No spacecraft has ever visited such an asteroid, although NASA’s Psyche mission, launched in October, is on a mission to a potential M-type asteroid, also called Psyche, between Mars and Jupiter. However, it won’t arrive until August 2029, giving AstroForge the chance to be the first to visit such an object.

To date, AstroForge has raised $13 million from investors. A full mining mission would require a much larger investment. But there is wealth to be made if the business is successful. On Earth, the metals that might be on M-type asteroids could be difficult and expensive to mine. Iridium, for example, sells for thousands of dollars per ounce.

The business case for extracting metals from asteroids has not always been so clear. It is difficult and expensive to return material to Earth; NASA’s OSIRIS-REx mission returned an estimated just half a pound of material from an asteroid called Bennu in September, at a cost of an estimated $1.16 billion.

AstroForge is confident in its financial prospects. “We expect to be able to return materials at a high margin,” Mr. Gialich said. “We created our business model using rideshare and partnerships to make each mission as economically feasible as possible.”

Akbar Whizin, a planetary scientist at the Southwest Research Institute, said he understood the motivation for keeping the asteroid secret. He previously worked for Planetary Resources, a mining startup never reached an asteroidand she too was cautious about her goals.

“This is a commercial venture,” he said. “You wouldn’t go around telling people, ‘I know where the gold is.'”

But some scientists believe asteroid miners should be more candid about what they’re looking for. M-type asteroids give humanity a glimpse into the chaotic early solar system of 4.5 billion years ago, when objects often collided and the planets were born. That means anything AstroForge discovers could be scientifically valuable, says Stephanie Jarmak, a planetary scientist also at the Harvard-Smithsonian Center for Astrophysics.

“I’m a pretty big believer in open science,” says Dr. Jarmak, also project scientist for NASA science explorer. “We have never visited an M-type asteroid before, so we can still learn a lot.”

That could include “insights into the heating processes that occurred early in the solar system’s history,” says Andy Rivkin, an astronomer at the Johns Hopkins University Applied Physics Laboratory who led NASA’s DART mission to orbit an asteroid in September 2022. to hit.

“We will never reach the core of the Earth,” he said. “So visiting these types of objects gives us information that we can extrapolate to learn more about Earth and apply it to different planets.”

Benjamin Weiss, a planetary scientist at the Massachusetts Institute of Technology and deputy principal investigator of the Psyche mission, said the true nature of M-type asteroids is still unclear. Although it was “always the main assumption” that M-type asteroids were metallic, we said, we didn’t know for sure.

In 2010, the European Space Agency’s Rosetta spacecraft flew past the asteroid Lutetia. Scientists discovered that it was not as metallic as suspected. That would make whatever AstroForge discovered all the more valuable, said Dr. Weiss.

Mr Gialich said AstroForge would be transparent except about the asteroid itself. “We don’t keep our mission a secret,” he said. “We plan to share the images.”

While AstroForge isn’t revealing its target asteroid, it may be possible to find out where the company is headed next.

About 30,000 asteroids are known to be near Earth, giving AstroForge many potential targets. But the company has said its target is less than 100 meters in size and can be reached within a year of launch. That means it must cross Earth’s orbit or at least pass close by. The asteroid is also suspected to be an M-type, which is brighter than other asteroids due to their potential metal content.

According to Mitch Hunter-Scullion, CEO of the Asteroid Mining Corporation, a potential competitor to Britain’s AstroForge, these clues narrow the list of potential targets to “about 300 asteroids.”

Dr. Jarmak further refined the potential targets, taking brightness and size into account. “We have a list of fourteen objects,” she said.

Of these, 2010’s CD55 is particularly promising, which is about 75 meters wide, is reasonably bright (indicating metallic content) and is reachable from Earth in the time frame of AstroForge’s launch date.

Mr. Gialich would not verify or deny that suggestion.

“We do not want to publicly confirm our target asteroid,” he said.

He added that there were several targets that AstroForge was considering. “We are actively monitoring several asteroids that would be viable for our Odin mission if our launch date were to shift,” he said.

Even if the asteroid cannot be identified before launch, Dr. McDowell notes that it might be possible for amateur astronomers on Earth to track the spacecraft after it gets into space and figure out where it’s going.

“There are some practical issues,” he says. “But I definitely think there will be interest in following it.”