The Osiris-REx mission delivers its first results. The asteroid Benu contains water and carbon, as scientists hoped, NASA announced Wednesday, revealing the first images of dust and blackened pieces of the largest asteroid sample ever reported on Earth. “Water and carbon molecules are exactly the kind of matter we wanted to find,” NASA Administrator Bill Nelson said at an event in Houston. These are crucial elements in the formation of our own planet, and they will help us determine the origin of elements that could have led to life. »
The Osiris-REx mission took this sample in 2020 from the asteroid Bénou, and the capsule containing the precious cargo successfully returned to Earth a little over two weeks ago, landing in the American desert.
Since then, the meticulous process of opening the capsule has taken place in a clean room at NASA’s Johnson Space Center in Houston. But the operation has already held some surprises.
The collection compartment not yet opened
Before the capsule landed, the American space agency estimated that it had succeeded in collecting around 250 grams of material on the asteroid Bénou, much more than two previous Japanese missions to other asteroids. NASA, for whom such a maneuver was a first, will still have to confirm this estimate.
Because, because of the abundance of material found even outside the collection compartment, its opening has not yet begun, said Eileen Stansbery, division chief scientist at the Johnson Space Center. “We take our time to methodically carry out treatment and properly care for each piece of Bénou,” she explained.
In fact, during the mission, the flap of the collection compartment was unable to close. The cargo had been secured by being transferred as planned into the capsule, but because of this leak scientists expected that residue would be found outside the compartment, in the box where it had been placed.
This “bonus” material, consisting of “black dust” and “debris”, in NASA’s words, was entrusted to a rapid analysis team, in order to obtain a first idea of ??the composition of Bénou. The sample was examined using a scanning electron microscope, X-ray diffraction and infrared measurements.
Understanding the origin of life
The study of asteroids should allow scientists to better understand the formation of the Solar System and how the Earth became habitable. Asteroids like Bénou could have brought to our planet the compounds that subsequently allowed the birth of life, some scientists believe.
The majority of the sample will be preserved to be studied by future generations, with new, more efficient instruments, in order to answer new scientific questions. This is what was done for the lunar rocks brought back during the Apollo program.
Bénou’s analysis could prove useful in another way. Although there is a small chance (1 in 2,700 chance) that the asteroid will hit Earth in 2182, the collision would be catastrophic. Knowing its exact composition could thus help, if necessary, to determine the preventive impact necessary to deviate its trajectory.