"Blew Us Away": Experts On Life-Building Chemicals In Asteroid Bennu Samples

Scientists have found special chemical compounds necessary for the existence of life in samples collected from asteroid Bennu. They believe the asteroid is a plant-like object rich in water and salt, according to NASA.

Named after an Egyptian bird, Bennu contains special minerals such as salts, phosphates, ammonia and dozens of protein-building amino acids. Other than this, it also contains five nucleobases needed for building blocks that make up RNA and DNA.

Professor Sara Russell, a cosmic mineralogist at the Natural History Museum in London and the lead author of Nature of the Bennu Minerals said, "There were things in the Bennu samples that completely blew us away, adding, "The diversity of the molecules and minerals preserved is unlike any extraterrestrial samples studied before."

Ms Russell said, "These strongly suggest that asteroids similar to Bennu crashed on Earth, bringing crucial ingredients that led to the appearance of life here."

Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington, said, "Asteroids provide a time capsule into our home planet's history, and Bennu's samples are pivotal in our understanding of what ingredients in our solar system existed before life started on Earth."

Ms Russell revealed how this asteroid could contain salt. She said, "Its parent world clearly had underground lakes of brine, and when these evaporated, they left behind salts that resemble those found in dry lake beds on Earth."

Scientists discovered 11 different minerals in the sample from Bennu, including calcite, halite and sylvite. These minerals are formed when water that contains dissolved salts slowly evaporates over time, leaving behind the salts as solid crystals.

In the solar system, similar brines have been found or predicted in locations such as Saturn's moon Enceladus and the dwarf planet Ceres.

Despite scientists previously finding a number of evaporites in meteorites that fall to the Earth's surface, they never observed a full set that preserves an evaporation process that may have lasted for thousands of years or longer. Some minerals, like trona, found in Bennu, were initially identified in samples from other planets.

Jason Dworkin, OSIRIS-REx project scientist at NASA Goddard and co-lead author on the Nature Astronomy paper, said, "OSIRIS-REx has been a highly successful mission."

The presence of minerals in asteroids has also boosted hopes of the presence of alien life. Scientists said that, although chemicals such as DMS and DMDS do not serve as direct proof of alien biological activity, they do suggest that life may exist in distant solar systems.