Asteroid Bennu contains the 'seeds of life,' OSIRIS-REx samples reveal

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https://www.livescience.com/chemistry/asteroid-bennu-contains-the-seeds-of-life-osiris-rex-samples-reveal?utm_term=032043BB-1CB4-4440-A845-2FF7DCCBD37B&lrh=1e7f7a9239bb44f191dc979b8fe5e634e587dfe020b84a653d2040468a8b342b&utm_campaign=368B3745-DDE0-4A69-A2E8-62503D85375D&utm_medium=email&utm_content=9CCC617F-0572-4C59-9EA2-70DB0E7E0BDF&utm_source=SmartBrief

Published 3 days ago on Jan 29, 2025

Scientists have found all five nucleobases alongside minerals essential for life as we know it on the potentially hazardous asteroid Bennu.

Scientists have discovered the essential building blocks to life on a sample from a distant asteroid.

The sample, which the OSIRIS-REx spacecraft collected from the asteroid Bennu and returned to Earth in 2023, contains all five nucleobases — the "letters" that make up DNA and RNA — alongside mineral compounds, all of which have never previously been seen on extraterrestrial rocks.

The minerals are rich in carbon, sulfur, phosphorus, fluorine and sodium, making them resemble those left in the crusts of dried lake beds on Earth — except they date to the birth of the solar system 4.6 billion years ago.

These elements, alongside the five nucleobases that make up DNA and RNA, are the basic building blocks for life on our planet.

The two teams of researchers who made the discoveries published their findings Jan. 29 in two papers in the journal Nature Astronomy.

"We now know from Bennu that the raw ingredients of life were combining in really interesting and complex ways on Bennu's parent body," study co-lead author Tim McCoy, curator of meteorites at the Smithsonian's National Museum of Natural History, said in a statement. "We have discovered that next step on a pathway to life."

Bennu is a potentially hazardous asteroid that has a 1-in-2,700 chance of striking Earth in the year 2182 — the highest odds of any known space object.

But scientists are more interested in what's trapped on the space rock: As a carbon-rich asteroid, it likely contains many of the primordial molecules present when life first emerged on Earth.

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The Nature Astronomy paper reports that the sample contains 14 of the 20 amino acids (which make proteins) found on Earth, all five nucleobases life uses for storing and transmitting genetic instructions, and high levels of ammonia—which can aid in the formation of amino acids.

As with any major discovery, Bennu also inspires more questions. For example, life on Earth only produces what are referred to as left-handed amino acids, but the asteroid contains an equal amount of left and right amino acids. It’s still a mystery why life adopted this left-handedness, and one scientists eventually hope to solve as they gather more information.