In 2023, a return capsule from the 2016 rocket probe “OSIRIS-REx” landed back on Earth. It carried samples of dust from an asteroid named “Bennu.” This dust contains 16,000 kinds of organic molecules, among them the 16 amino acids our cells use to make proteins. The dust also contains all four of the large nucleobases that compose our DNA.

The journal NATURE reported that scientists think a larger “Parent” asteroid formed in the outer solar system, beyond the orbit of Jupiter.  Far from the sun’s heat, the parent asteroid was likely kept warm by interior radioactivity, allowing organic molecules to form in warm pools or undersea vents.  At some point, Bennu’s parent asteroid was blasted into an orbit between Mars and Earth. There, it was smashed into bits by a later collision. One of those bits is the ball of dust called Bennu.

Scientists at universities concur that this discovery strongly implies that the molecular processes leading to Life happened at locations other than planet Earth. (See, “Lurking Inside an Asteroid: Life’s Ingredients,” reported by Carl Zimmer for The New York Times, 1-31-2025.) 

“In January 2025, it was reported that a wide range of carbon- and nitrogen-rich organic compounds have been identified in samples returned from Bennu, including 14 of the 20 amino acids that make up proteins in terrestrial organisms, as well as all four nucleobases (adenine, thymine, cytosine, and guanine) that are the essential building blocks of DNA and RNA. The samples contain a nearly equal mix of left-handed (L) and right-handed (D) amino acids, raising possibilities about whether asteroids like Bennu helped shape Earth’s biochemistry.” (Quoted from Wikipedia article, “OSIRIS-REx.”)

Photo of the Asteroid named “Bennu” in space.