“Organic molecules delivered from extraterrestrial materials may have played a key role in supplying building blocks for life on Earth,” said one scientist.

Scientists have discovered all five nucleobases—the fundamental components of DNA and RNA—in pristine samples from the asteroid Ryugu, according to a study published on Monday in Nature Astronomy. The finding strengthens the case that the ingredients for life are abundant in the solar system and may have found their way to Earth from space, according to a study published on Monday in Nature Astronomy.

Life as we know it runs on DNA and RNA, which are built from five chemical bases: adenine, guanine, cytosine, thymine, and uracil. A team has now identified this “complete set” of nucleobases in rocks snatched from the surface of Ryugu in 2019 by the Japanese spacecraft Hayabusa-2, which successfully returned them to Earth the following year.