"Glimpse into Untouched Asteroid Dust Uncovers Surprising Riches of Water and Carbon" - blog.sciencenatures

Sunday, October 15, 2023

"Glimpse into Untouched Asteroid Dust Uncovers Surprising Riches of Water and Carbon"

NASA's OSIRIS-REx mission has unveiled a groundbreaking discovery: the sample collected from the ancient asteroid Bennu, which dates back 4.5 billion years, contains abundant water and carbon. This finding provides compelling support for the theory that life on Earth might have originated from extraterrestrial sources.

After a seven-year round trip to Bennu, the spacecraft delivered its precious cargo to the Utah desert, initiating meticulous scientific analysis. NASA Administrator Bill Nelson announced this significant achievement at a press event in Houston's Johnson Space Center, where the initial images of black dust and pebbles were showcased.

The sample, the largest carbon-rich asteroid sample ever brought to Earth, contains nearly five percent carbon by weight, present in both organic and mineral forms. Additionally, water was found locked within the crystal structure of clay minerals. Scientists posit that Earth's water bodies were formed around 4 to 4.5 billion years ago when the planet was struck by water-carrying asteroids, rendering Earth habitable. Carbon, the foundation of life on Earth, forms essential compounds like proteins, enzymes, DNA, and RNA.

Advanced techniques such as scanning electron microscopy and X-ray computed tomography facilitated this preliminary analysis. Astrobiologist Daniel Glavin expressed enthusiasm about the findings, highlighting the extensive research potential. The sample will be shared with labs worldwide for further examination.

While Japan had previously succeeded in retrieving celestial dust from asteroids in 2010 and 2020, OSIRIS-REx outperformed its predecessors by collecting an estimated 250 grams (half a pound) of material. Bennu, named after an ancient Egyptian deity, is considered a "primordial artifact preserved in the vacuum of space," making it a valuable subject for study. Its orbit intersecting with Earth's path made the mission more feasible compared to reaching the Asteroid Belt between Mars and Jupiter.

Apart from scientific insights, understanding Bennu's composition could aid in future efforts to redirect it away from Earth. Although there is no imminent risk of collision until the mid-2100s, the likelihood increases to 1 in 1,750 between 2100 and 2300, according to NASA.

Notably, OSIRIS-REx's sample collection exceeded expectations, with particles so loosely packed that a person stepping onto the surface might sink in, akin to a pit of plastic balls in children's play areas. Researchers have primarily focused on analyzing "bonus particles" lying atop the sample collection mechanism, with further inspection of the remaining sample slated for future study.

NASA plans to preserve at least 70 percent of the sample in Houston for future research, a practice reminiscent of the Apollo era's preservation of Moon rocks. Additionally, select pieces will be displayed publicly at institutions like the Smithsonian Institution, Space Center Houston, and the University of Arizona, allowing the public to marvel at these extraterrestrial treasures.

No comments:

Post a Comment