Did Life on Earth Come from Asteroids? 

A correspondent brought THIS ARTICLE to my attention. It concerns the discovery of amino acids in the asteroid 162173 Ryugu. 5 grams of this asteroid were brought to Earth by the Hayabusa2 space mission. 

Amino acids are essential for life. They are not difficult to make - and the Ryugu discovery suggests that they could be made by gamma rays in asteroids! 

The carbonaceous chondrite Murchison meteorite which landed in Australia in 1969 had amino acids and their concentration in the meteorite could have been raised from zero, by gamma rays, in anything from 1,000 up to 100,000 years.

Part of the Murchison meteorite, photographed in the Maine Mineral and Gem Museum, Bethel, Maine by me on 5th October 2022.

The article notes that amino acids in the early Earth could have come from several, if not many, sources. Asteroids have been added to the list.