All the ingredients of our DNA have been found on meteorites now, scientists say. What does this mean? Quite simply that life on Earth could have come from space.
Rocks from space that crashed into our planet Earth over the last century contained the five base components that store information in DNA and RNA, scientists wrote in Nature Communications on April 26.
The five "nucleobases" are adenine, guanine, cytosine, thymine, and uracil, along with a few sugars and phosphates together create genetic code of all life on Earth.
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A 2-gram chunk from this rock — a piece of the meteorite that fell near Murchison, Australia, in 1969 — contains two crucial components of DNA and RNA now identified for the first time in an extraterrestrial source, researchers say. |
Scientists think that these ingredients either came to Earth from space or grew in an early hot soup on the planet. With these new findings, the former theory has more evidence.
How were these compounds extracted?
Adenine, guanine are among the few compounds that were found in meteorites since the 1960s, scientists say. Traces of uracil were also picked up, but cytosine and thymine still remain "elusive," Science News reported.
Daniel Glavin from NASA's Goddard Space Flight Center said that they've "completed the set of all the bases found in DNA and RNA and life on Earth" and that "they’re present in meteorites."
The study was undertaken by Yasuhiro Oba's team from Hokkaido University in Japan and astrochemists at NASA. A few years ago, Oba developed a technique to delicately excavate and separate different chemical compounds found in meteorite dust.
Using their mild extraction technique that uses cold water instead of acids, scientists found life-creating bases and compounds in four meteorite samples from Australia, US state of Kentucky, and Canadian province of British Columbia.
The discovery of these compounds in meteorites means that it is possible life on Earth as it stands today was created by compounds that came from outer space.