Cape Canaveral, Fla. • NASA on Wednesday showed off its first asteroid samples delivered last month by a spacecraft — a jumble of black dust and rubble that’s the most ever returned to Earth.
Scientists anticipated getting a cupful but are still unsure how much was grabbed from the carbon-rich asteroid named Bennu, almost 60 million miles away. That’s because the main sample chamber has yet to be opened, officials said during an event at Johnson Space Center in Houston.
“It’s been going slow and meticulous, but the science is already starting,” said the mission’s lead scientist, Dante Lauretta of the University of Arizona.
NASA’s OSIRIS-REx spacecraft collected the samples three years ago from the surface of Bennu and then dropped them off sealed in a capsule during a flyby of Earth last month. That capsule landed in Utah’s West Desert, was decontaminated at Dugway Proving Ground and then flown by military jet to Houston.
The expected cupful of material from Bennu’s surface was far more than the teaspoon or so that Japan brought back from a pair of separate asteroid missions.
(Francisco Kjolseth | The Salt Lake Tribune) A live feed captures the capsule containing an asteroid sample, charred from entering the earth’s atmosphere, as it is delivered to a temporary clean room at Dugway Proving Grounds on Sunday, Sept. 24, 2023. The Osiris-Rex spacecraft released the capsule following a seven-year journey to asteroid Bennu and back.
Black dust and particles were scattered around the outside edge of the internal sample chamber, according to Lauretta. He said there’s still “a whole treasure chest of extraterrestrial material” to be studied. The samples are priceless, the preserved building blocks from the dawn of the solar system.
No one at Wednesday’s celebration at Johnson got to see any of the samples firsthand — just photos and video. The asteroid pieces were behind locked doors in a new lab at the space center, accessible only to scientists in protective gear.
Besides carbon, the asteroid rubble holds water in the form of water-bearing clay minerals, Lauretta and others pointed out.
“That is how we think water got to the Earth,” he said. “Minerals like we’re seeing from Bennu landed on Earth 4 billion years ago to 4.5 billion years ago, making our world habitable.”
That was one of the primary reasons for the $1 billion, seven-year mission: to help learn how the solar system — and Earth in particular — formed. “You can’t get more exciting than that,” said NASA Administrator Bill Nelson.
Back in 2020, Lauretta and his team lost some of their haul when the lid on the sample container jammed a few days after the spacecraft collected the material. It vacuumed up so many pieces from Bennu that small rocks got lodged under the lid and prevented it from closing, sending pieces floating off into space.
(Francisco Kjolseth | The Salt Lake Tribune) A NASA capsule containing a sample from the surface of asteroid Bennu, the first such sample taken by a U.S. space mission, is transported to a temporary clean room at Dugway Proving Grounds on Sunday, Sept. 24, 2023.
That’s why scientists did not have a precise measurement of what was coming back; they estimated 250 grams, or about a cupful, ahead of the Sept. 24 landing in the Utah desert. They won’t have a good count until the container is opened, within two weeks or so.
While scientists hope the OSIRIS-REx mission, and the sample it’s returned, will help them further understand the origins of our universe, part of their job is also researching how well the spacecraft’s other systems operated during the mission. To do this, they’ll compare the results from the spacecraft’s onboard instruments to the actual minerals collected from Bennu.
“By bringing some of that sample here to Johnson Space Center, and ultimately distributing it around the earth, so far we’re validating those instruments — they really look like they performed well, their sensitivity was as we expected, in fact, exceeded it by a bit,” Lauretta told reporters Wednesday.
Further calibrating those instruments will allow scientists to “do an even better job characterizing asteroid Apophis,” he explained of OSIRIS’s next mission.
After the spacecraft delivered its Bennu sample to Earth last month, the mission was renamed OSIRIS-APEX, for Apophis Explorer. Once arriving at its destination, the spacecraft will use its visual sensors to study Apophis, just as it did Bennu.
(Leah Hogsten | The Salt Lake Tribune) The Space Dynamics Laboratory's detector assemblies created for the three high-resolution cameras in the OSIRIS-REx Camera Suite (OCAMS) for NASAÕs first mission to obtain material from the asteroid Bennu to provide insight into the origins of the universe.
Some of the sensors, specifically a suite of three cameras called the OCAMS, were partially developed and tested at Utah State University’s Space Dynamics Laboratory.
“This was about ground-truthing our astronomical data, as well as our spacecraft-based data. A lot of our sample analysis plan is focused around understanding how well those instruments are capable of characterizing the surface,” Lauretta said. “So far, it looks really good, and that gives a lot of confidence going into the APEX extended mission.
Much of the material shown Wednesday was overflow from when the lid was stuck open, before everything could be sealed inside the return capsule. The larger visible rocks were under an inch in size.
“We have a bounty of sample on our hands already and we’re not even inside” the main sample container, said NASA astromaterials curator Francis McCubbin.
Once the samples are archived, the team will dole out particles to researchers around the world, while saving a fair amount for future analysis when better technology should be available.
NASA has another asteroid-chasing spacecraft on a Florida launch pad, ready to blast off later this week. The destination will be a rare asteroid made of metal named Psyche. No samples will be coming back.
The Salt Lake Tribune’s Jeff Parrott reported from Utah.
