NASA's OSIRIS-REx probe has discovered ingredients for water in an asteroid the size of a relatively nearby skyscraper, an acorn-shaped rocky object that may hold clues to the origins of life on Earth, scientists say.
OSIRIS-REX, which flew last week within 19 km of the asteroid Bennu, 2.25 million kilometers from Earth, has found traces of hydrogen and oxygen molecules – part of the water's revenue and therefore life potential – embedded in the rocky surface of the asteroid. .
The probe, on a mission to return asteroid samples to Earth for study, was launched in 2016.
Bennu, about 500 meters wide, orbits the sun about the same distance as Earth. There is concern among scientists about the possibility of Bennu impacting the Earth in the late 22nd century.
"We find the water-rich minerals of the primitive solar system, which is exactly the kind of sample that we would find and ultimately bring back to Earth," said Dante Lauretta, a planetary scientist at the University of Arizona, the mission of OSIRIS- REx. principal investigator, said in a telephone interview.
Asteroids are among the remains of the formation of the solar system 4.5 billion years ago.
Scientists believe that asteroids and comets colliding with primitive Earth may have released organic compounds and water that sowed the planet for life, and atomic-level analysis of Bennu's samples could provide important evidence to support this hypothesis.
"When samples of this material are returned by the Earth mission in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system," said Amy Simon, a scientist at NASA's Goddard Space Flight Center in Maryland. said in a statement.
"We are really trying to understand the role that these carbon-rich asteroids play in providing water to the primitive Earth and making it habitable," added Lauretta.
OSIRIS-REx will pass later this month just 1.9 km from Bennu, entering the gravitational pull of the asteroid and analyzing its terrain. From there, the spacecraft will begin to gradually tighten its orbit around the asteroid, spiraling just two meters from its surface so that its robotic arm can capture a sample of Bennu by July 2020.
The spacecraft will fly back to Earth, discarding a capsule with the asteroid specimen for a parachute descent in the Utah desert in September 2023.