NASA asteroid sample has life-critical water

A sample collected from the 4.5bn-year-old asteroid Bennu contains abundant water and carbon, NASA has revealed.

Asteroid Bennu, imaged by NASA’s Osiris-Rex spacecraft. Picture: NASA / Goddard / University of Arizona

A sample collected from the 4.5 billion-year-old asteroid Bennu contains abundant water and carbon, NASA has revealed, offering more evidence for the theory that life on Earth was seeded from outer space.

The discovery follows a seven-year round trip to the distant rock as part of the OSIRIS-REx mission, which dropped off its precious payload in the Utah desert in September for painstaking scientific analysis.

“This is the biggest carbon-rich asteroid sample ever returned to Earth,” NASA administrator Bill Nelson said at the Johnson Space Centre in Houston, where first images of black dust and pebbles were ­revealed.

Carbon accounted for almost five per cent of the sample’s total weight, and was present in both organic and mineral form, while the water was locked inside the crystal structure of clay minerals, he said.

Scientists believe the reason Earth has oceans, lakes and rivers is because it was hit with water-carrying asteroids 4 to 4.5 billion years ago, making it a habitable planet.

All life on Earth is based on carbon, which forms bonds with other elements to produce proteins and enzymes as well as the building blocks of genetic code, DNA and RNA.

The findings were made through a preliminary analysis involving scanning electron microscopy, X-ray computed tomography and more.

“This stuff is an astrobiologist’s dream,” said scientist Daniel Glavin, adding there was much more work to be done and the sample would be shared with labs around the world for further study.

Better understanding of Bennu’s composition could prove useful if humanity ever needs to steer it away.

AFP