Could life have come from space? NASA asteroid Bennu samples reveal building blocks of life

Asteroid Bennu (Image: NASA)

Scientists have discovered vital chemical compounds in dust from Bennu. The asteroid sample, collected by NASA’s Osiris-Rex mission, contains organic molecules essential for life. This finding supports the idea that asteroids may have brought these elements to Earth billions of years ago.

What Was Found in Bennu’s Dust?
Researchers analysing the sample found thousands of organic compounds. These include amino acids, which are essential for proteins, and nucleobases, the building blocks of DNA. The sample also contained nitrogen and carbon-rich compounds, including 14 of the 20 amino acids used by life on Earth. Scientists even detected all four DNA nucleobases—adenine, guanine, cytosine, and thymine.

Researchers analysing the sample found thousands of organic compounds. (Image: NASA)

The presence of minerals and salts suggests that water once existed on Bennu. Ammonia, which is crucial for biochemical reactions, was also identified in the sample. While similar compounds have been found in meteorites, some elements in Bennu’s dust have never been seen before.

Why Is This Discovery Important?
These findings add weight to the theory that asteroids helped deliver life’s ingredients to Earth. Scientists believe similar organic materials could have reached other planets in the Solar System.

Prof Sara Russell, a cosmic mineralogist from the Natural History Museum in London, expressed excitement over the discovery. “Every grain is telling us something new about Bennu,” she said.

The study, published in Nature, involved scientists from around the world. The UK team received about a teaspoonful of the 120g sample collected. Despite the small amount, it has provided a wealth of new information.

NASA’s Osiris-Rex mission successfully collected the sample in 2020 and returned it to Earth in 2023. Scientists continue to analyse Bennu’s dust, hoping to uncover more secrets about the origins of life.