All five DNA/RNA building blocks found in asteroid Ryugu samples

Every nucleobase needed to build DNA and RNA — adenine, guanine, cytosine, thymine, and uracil — has been found in rock samples from the asteroid Ryugu, according to a study published in Nature Astronomy. Previous research in 2023 had found only uracil. A Japanese team led by Toshiki Koga identified all five.

Getting those samples was a six-year effort. Japan's Hayabusa-2 spacecraft launched in 2014, traveled 300 million km, landed on the 900-meter-wide asteroid, scooped up 5.4 grams of rock, and returned to Earth in 2020.

Ryugu isn't the only space rock carrying these molecules. NASA found the same building blocks on asteroid Bennu, and they've turned up in the Orgueil and Murchison meteorites as well.

"Their presence indicates that primitive asteroids could produce and preserve molecules that are important for the chemistry related to the origin of life," Koga said. The researchers also found a correlation between nucleobase ratios and ammonia concentration, pointing to what they describe as "a previously unrecognized pathway for nucleobase formation."

This does not mean life existed on Ryugu. It means the raw ingredients for life are floating around in space, surviving millions of years on chunks of rock, and occasionally landing on planets.

Previously:

• Building blocks of life found on asteroid
• NASA reveals asteroid sample contains building blocks of life