NASA scientists have uncovered vital clues about the origins of life from asteroid Bennu. On Monday, researchers confirmed that samples collected by the OSIRIS-REx mission contain complex organic molecules, including all five nucleobases that form DNA and RNA. These findings suggest asteroids like Bennu may have helped spark life on Earth. The discovery was led by Prof. Sara Russell of London’s Natural History Museum and was published in Nature. The asteroid, thought to be a fragment from a water-rich planet that broke apart billions of years ago, continues to reshape our understanding of cosmic chemistry and life’s beginnings.
A Historic Collision That Sparked New Questions
Billions of years ago, a collision shattered a water-rich world in our young solar system. One of the fragments became asteroid Bennu. In September 2023, NASA’s OSIRIS-REx spacecraft delivered a 120-gram sample from Bennu to Earth.
These small grains of dust hold big answers.
Prof. Sara Russell, lead scientist at the Natural History Museum, shared her amazement:
“There were things in the Bennu samples that completely blew us away,” she said. “We found new minerals and organic compounds that we didn’t expect to see.”
Evidence of Life’s Ingredients in Bennu’s Dust
The Bennu sample contained phosphates, ammonia, salts, and over a dozen amino acids. Most importantly, researchers detected all five nucleobases – the key elements of DNA and RNA: adenine, guanine, cytosine, thymine, and uracil ancient asteroid sample.
These are the chemical letters of life as we know it.
“This is strong evidence that building blocks of life came from space,” Russell explained. “Asteroids like Bennu likely delivered these molecules to early Earth.”
The finding supports the theory that life’s seeds may have arrived on Earth through asteroid impacts over 3.7 billion years ago.
Bennu Samples: A Rare Glimpse into Cosmic History
The OSIRIS-REx mission marks the first time the U.S. has returned material from an asteroid. Only Japan’s Hayabusa2 mission has done this before.
A surprising bonus came in the form of a never-before-seen phosphorus compound – a key component of life. Initially thought to be contamination, further testing confirmed its cosmic origin.
Researchers remain stunned.
“The presence of phosphorus in this form is unprecedented,” said one NASA team member. “It expands our understanding of how complex chemistry forms in space.”
What’s Next? Public Can Explore in New London Exhibit
The Natural History Museum in London will open a new exhibition titled “Space: Could Life Exist Beyond Earth?” on 16 May 2025. The exhibit will include Bennu’s dust, meteorites older than Earth, and real Martian and lunar samples.
Sinead Marron, senior exhibitions manager, explained the goal:
“We want people to consider what finding alien life would really mean,” she said. “Would we protect it, study it, or treat it like any other resource?”
The exhibit also dives into upcoming missions that are looking for life across the solar system.
Search for Life Continues Across the Solar System
While Bennu may have brought ingredients for life, scientists are now targeting moons and planets that could host it today.
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Europa and Ganymede, moons of Jupiter, are believed to have deep oceans beneath their icy crusts.
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Enceladus and Titan, moons of Saturn, continue to show signs of water activity and organic molecules.
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The UK’s Rosalind Franklin rover is set to land on Mars in 2029, where it will drill below the surface to search for signs of ancient microbial life.
Webb Telescope Detects Possible Life Signs on Exoplanet
The cosmic quest took another leap last week. NASA’s James Webb Space Telescope spotted molecules linked to life in the atmosphere of K2-18b, an exoplanet 120 light-years away.
The telescope identified dimethyl sulfide and dimethyl disulfide – chemicals known to be made only by living organisms on Earth.
Though not proof of alien life, the discovery adds to growing excitement.
As our tools improve, the mystery of life beyond Earth inches closer to reality. Whether it began with asteroid dust or brews today under icy moons, the universe may be far more alive than we thought.
Back on Earth, the discovery of Bennu’s ancient molecules has reignited age-old questions.
“We have to ask ourselves what life means,” Marron said. “And how we should treat it—whether it’s alien or our own.”