Bennu was the target of the OSIRIS-REx mission that returned samples of the asteroid to Earth. Now, research published in Nature has shown that those samples have all the chemical building blocks for RNA. This is significant, as it's thought that before life settled onto DNA as its organizing mechanism, it first evolved through an RNA stage.

Bennu is thought to be formed from a protoplanet that was formed very early in the Solar System's history, but fragmented 1-2 billion years ago. If this protoplanet formed RNA precursors, and Bennu harbored them undamaged for 1-2 billion years in deep space, it suggests the Universe must be widely seeded with RNA. If that is the case, then there may be billions of planets seeded with such precursors, where the chances of life evolving via RNA could have happened as they did on Earth.

The next 5-10 years will see several space and ground-based telescopes capable of scanning exoplanet atmospheres for the biosignatures of alien microbial life. This new finding about asteroid Bennu suggests we may find life in many of those exoplanets.

Bio-essential sugars in samples from asteroid Bennu