Astroids Delivered the Chemistry of Life to Earth?

In Nature Communications, investigators at Hokkaido University, the Japan Agency for Marine-Earth Science and Technology, and other centers in Japan and the US describe the detection of the RNA nucleotide base uracil in samples from the carbonaceous asteroid Ryugu, sampled via two touchdown efforts by the spacecraft Hayabusa2. Following from past studies suggesting the near-Earth asteroid contained amino acids and other organic molecules, the team relied on a combination of high-performance liquid chromatography and electrospray ionization high-resolution mass spectrometry to assess aqueous samples obtained with a 20-hour hot water extraction on Ryugu samples collected at two sites where the spacecraft touched down, comparing the samples to hot water-extracted samples from a meteorite called Orgueil. In the process, the authors identified uracil in the Ryugu samples, together with imidazoles, nicotinic acid, and related molecules. "The present study strongly suggests that such molecules of prebiotic interest commonly formed in carbonaceous asteroids including Ryugu and were delivered to the early Earth," the authors suggest.

Uracil's use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates. Uracil serves as allosteric regulator and coenzyme for reactions in animals and in plants.