A seven-year space journey came to an end Sunday as a NASA spacecraft landed in the Utah desert, transporting the largest asteroid samples ever collected back to Earth.
Scientists have high hopes for the sample, saying it would help them understand how our solar system formed and how Earth became livable.
.“Touchdown of the Osiris-Rex sample return capsule!” a commentator said on NASA’s live video webcast of the landing, as engineers and team members applauded at a nearby mission control center.
The 3.86-billion-mile (6.21-billion-kilometer) flight was the US space agency’s first sample return mission of its kind, according to a post on X, the old Twitter.
NASA Administrator Bill Nelson applauded the effort, saying the asteroid dust “will give scientists an extraordinary glimpse into the beginnings of our solar system.”
The Osiris-Rex probe’s final, scorching plunge through Earth’s atmosphere was risky, but NASA managed to orchestrate a soft landing in the military’s Utah Test and Training Range at 8:52 a.m. local time (1452 GMT).
Four years after its launch in 2016, the spacecraft arrived on the asteroid Bennu and collected approximately nine ounces (250 grams) of dust from its rocky surface.
Even that small amount, NASA says, should “help us better understand the types of asteroids that could threaten Earth.”
The sample return “is really historic,” NASA scientist Amy Simon told AFP. “This is going to be the biggest sample we’ve brought back since the Apollo moon rocks” were returned to Earth.
Osiris-Rex released its capsule early Sunday from an altitude of more than 67,000 miles.
The capsule hurtled downward at a speed of more than 27,000 miles per hour, with temperatures reaching 5,000 degrees Fahrenheit (2,760 degrees Celsius) in the last 13 minutes.
Two successive parachutes were supposed to slow its rapid drop as it approached the 37-mile by nine-mile landing zone.
According to NASA, the primary chute deployed “much higher than was originally anticipated,” at around 20,000 feet (6,100 meters) rather than 5,000 feet.
The tire-sized capsule was seen on the ground in a desert wash, with scientists approaching it and taking measurements.
Eventually they concluded the capsule was not breached, meaning its all-important air-tight seal remained intact, avoiding any contamination of the sample with desert sands.
The team then lifted the capsule by helicopter to a nearby “clean room.”
Meanwhile, the probe that made the space journey fired its engines and shifted course away from Earth, NASA said, “on its way” for a date with another asteroid, known as Apophis.
Scientists predict that asteroid will come within 20,000 miles of Earth in 2029.
The sample will be sent to NASA’s Johnson Space Center in Houston for further analysis on Monday, and the first results will be announced at a news conference on October 11.
The majority of the sample will be saved for future generations to study. Approximately one-fourth will be used immediately in tests, with the remainder shipped to mission partners Japan and Canada.
Japan had already provided NASA a few grains from asteroid Ryugu in exchange for transporting 0.2 ounces of dust to Earth during the Hayabusa-2 mission in 2020. It had returned a minuscule amount from another asteroid ten years previously.
But the sample from Bennu is much larger, allowing for significantly more testing, Simon said.
Earth’s Origin Story
Asteroids are composed of the original materials of the solar system, dating back some 4.5 billion years, and have remained relatively intact.
They “can give us clues about how the solar system formed and evolved,” said Osiris-Rex program executive Melissa Morris.
“It’s our own origin story.”
By striking Earth’s surface, “we do believe asteroids and comets delivered organic material, potentially water, that helped life flourish here on Earth,” Simon said.
Scientists believe Bennu, which has a diameter of roughly 500 meters (1,640 feet), is rich in carbon — a building ingredient of life on Earth — and contains water molecules trapped in rocks.
Bennu startled scientists in 2020 when the probe sank into the soil during its brief contact with the asteroid’s surface, showing a surprisingly low density, similar to a children’s pool filled with plastic balls.
Understanding its composition could come in handy in the — distant — future.
Because there is a modest but non-zero risk (one in 2,700) that Bennu will collide with Earth catastrophically in 2182.
However, NASA successfully altered the trajectory of an asteroid last year by smashing a probe into it in a test, and it may need to repeat that exercise in the future — but with far larger stakes.