DNA’s Building Blocks May Have Arrived from Space, Asteroid Ryugu Samples Suggest
Samples returned by JAXA’s Hayabusa-2 mission from the C-type asteroid (162173) Ryugu contain all five canonical nucleobases — purines (adenine and guanine) and pyrimidines (cytosine, thymine and uracil) — pointing to a cosmic origin for some of life’s fundamental chemistry. Hayabusa-2 image of the asteroid Ryugu as seen from a distance of 3.7 miles. A…