Are we aliens? This question has come up due to a new result from studying meteorites, and is getting a lot of web-chatter. I figure I'd better get on this sooner rather than later! First, the science. Then the chatter. Finally, the caution flag. :-) The Science:
Some meteorites have been found to contain some relatively complicated organic compounds, including molecules that are components of amino acids, the building blocks of life. For example, the Murchison meteorite, which fell on Australia in 1969, has been found to contain purines and pyrimidines, which are crucial to a large number of biological molecules like DNA, RNA, and ATP (adenosine triphosophate, a chemical our cells use for fuel). Now, you have to be careful. A meteorite might have had these molecules in it before it slammed into the Earth, or it may have absorbed them from the ground after impact. One way to ...