A bright fireball streaked across the sky above mountains, glaciers, and spruce forests in British Columbia, Canada, on March 31, 1965. The meteorite fragments that fell over a lake provided a unique glimpse into the birth of the solar system. Nearly 60 years later, NASA’s OSIRIS-REx mission returned from space with a sample of asteroid Bennu, similar to the one that rained rocks over Revelstoke.
A recent study published by researchers has analyzed the samples, revealing insight into how some of the ingredients for life may have first arrived on Earth. The asteroid’s surface is rich in carbon and water-bearing clays, and veins of white carbonate were deposited by ancient liquid water. However, it was the presence of rarer minerals that caught scientists’ attention.
The team identified sodium-rich minerals, including carbonates, sulfates, chlorides, fluorides, potassium chloride, and magnesium phosphate. These minerals don’t form just when water and rock react; they form when water evaporates. The researchers found that these minerals are also present on icy bodies in the outer solar system, such as the dwarf planet Ceres and Saturn’s moon Enceladus.
The discovery of these minerals is significant because it suggests that asteroids like Bennu could have provided a complete package of complex molecules and essential ingredients for life when they hit young Earth. The presence of ammonia, an essential building block of amino acids, was also found in the sample. This finding implies that the briny water from which the minerals formed would have been an ideal place for new chemical reactions to take place and for organic molecules to form.
The study’s findings offer a glimpse into the early history of our planet and the potential for life to emerge from the building blocks of asteroids. The presence of these ingredients on Earth could have seeded the landscape, producing a habitable world. Without this early bombardment, it’s possible that the fragments from outer space would not have arrived in a landscape punctuated with glaciers and trees.
The OSIRIS-REx mission has provided a unique opportunity for scientists to study the composition of asteroid Bennu and its potential role in the origins of life on Earth. The discovery of these rarer minerals and the presence of essential ingredients for life offers new insights into the early history of our planet and the possibility of life beyond Earth.
Source: https://www.pbs.org/newshour/science/the-bennu-asteroid-reveals-clues-to-how-the-building-blocks-of-life-on-earth-may-have-been-seeded