NASA has recovered a ‘treasure’, the largest asteroid sample ever collected | TV5MONDE

Seven years after its launch, the Osiris-Rex probe has accomplished its mission: delivering a “treasure” to humanity: the largest asteroid sample ever collected in space, and the first by NASA.

The capsule containing the sample, taken in 2020 from the asteroid Bennu, landed on Sunday in the Utah desert in the United States, at the end of a stunning final descent through the Earth’s atmosphere, at a speed of 44,000 km/hour.

The fall, which was noticed by military sensors, had to be slowed by two successive parachutes. NASA has not confirmed whether the first was successful or not, but the second was successfully deployed, allowing for a smooth landing.

“We heard the sound of the main parachute opening, and I burst into tears,” Dante Lauretta, the mission’s scientific director, said at a press conference. “That’s the moment I knew we were home.”

“For me, the science is just beginning,” the researcher added.

The sample contains about 250 grams of material, according to the US space agency, which is much more than the two previous asteroid samples returned by Japanese missions.

Bennu’s analysis should give us a better understanding of the formation of the solar system, and how Earth became habitable.

After landing, the team first analyzed the capsule on Earth to confirm its condition. No violation was observed.

They were then wrapped and placed in a net, then lifted by helicopter and transported to a temporary “clean room”.

The challenge was to expose the capsule for the shortest possible time to the American desert sand, in order to avoid any contamination of the sample that could distort subsequent analyses.

The target area on the ground for landing was 58 kilometers long and 14 kilometers wide, and it was a military base usually used to test missiles.

About four hours before landing, the Osiris-Rex probe launched the capsule containing the sample, more than 100,000 kilometers from Earth. This probe then set off to visit another asteroid.

Two Japanese samples

“The return of this sample is truly historic,” NASA scientist Amy Simon told AFP this week. This is “the largest sample of lunar rock we have ever brought back” from the Apollo program, which ended in 1972.

The precious package will be transported on Monday to the Johnson Space Center in Houston, Texas. This is where the box will be opened, in another sealed room.

NASA plans to hold a press conference on October 11 to reveal the initial results.

The majority of the sample will be preserved for study by future generations. About 25% of it will be used immediately for trials, and a small portion will be shared with partners Japan and Canada.

Japan itself provided NASA with some grains from the asteroid Ryugu, of which it returned 5.4 grams in 2020, during the Hayabusa-2 mission. In 2010, a microscopic amount was reported from another asteroid.

This time, Bennu’s sample is much larger, so more analyzes will be possible.

It is “a treasure trove for scientific analysis, for years to come, for our children and grandchildren, and people yet to be born,” said Lori Glaze, NASA’s planetary science director.

History of our origin

Asteroids are composed of the original materials of the solar system, 4.5 billion years ago. Unlike Earth, it remained intact.

They therefore hold clues about how the solar system was formed.

Scientists believe that Bennu (500 meters in diameter) is rich in carbon, and contains water molecules trapped in minerals.

Dante Lauretta said: “The main goal for me (…) is to try to understand whether these carbon-rich asteroids like Bennu brought compounds that could lead to the birth of life on our planet.”

During the mission, the asteroid actually surprised scientists: its surface turned out to be less dense than expected during sample collection. The probe arm sank, as if in a ball pit.

However, a better understanding of their composition may be useful in the future.

There is a small chance (one in 2,700) that Bennu will hit Earth in 2182, an impact that could be catastrophic. But last year, NASA was able to divert an asteroid by colliding with it.