Meteorites recovered in Antarctica and Australia lead scientists to believe DNA building blocks exist in space.
If terms like adenine and guanine bring back unpleasant memories of Genetics 101 here's one reason to give the words a second thought: A team of scientists has discovered that these and other DNA building blocks can form in outer space and have been deposited on Earth's surface by meteorites. To reach this eye-opening conclusion, researchers ground up and analyzed a set of 12 meteorites collected from Antarctica and Australia. Within them, the scientists found a treasure trove of molecules that may have played a key role in allowing early forms of life to form. Adenine, which helps make up the rungs of DNA's spiraling, ladder-like structure, turned up in eleven of the meteorites. Guanine, another key building block of DNA, was present in eight. Two of the 12 also contained something extraordinary—exotic molecules that are so rare on Earth that they prove the DNA building blocks must have formed in outer space. The discovery lends support to the theory that a kit of pre-made parts from meteorites or a comet might have kick-started life on Earth. Learn more about the breakthrough in the video below.