MURCHISON METEORITE—A WELCOME VISITOR
As the world was celebrating the Apollo moon landing in 1969, humanity was greeted by a visitor—and a very welcome one, at that. On the morning of September 28, 1969, Australians witnessed a meteorite fall in Murchison, Australia—this piece of space rock has become one of more celebrated visitors from space (second only to the ALH84001, the Alan Hills Meteorite).
The Murchison meteorite is celebrated for many reasons, mainly of course; the detailed analysis of its constituents has yielded a treasure trove of data and some speculation, also. Firstly, speculation is, at times, part of the human condition—so I will put it aside.
Technically, the Murchison meteorite is known as a carbonaceous chondrite and it said to be about as old as the Solar System, itself. But, one major, distinguishing feature of this rock is the amount of organic compounds that have been identified within its matrix. According to two publications (listed below), it contains up to several thousand different organic compounds (many of the compounds may have some biological significance). Although it should be emphasized that no DNA, RNA—or fossilized remains of any type of organism were found within the Murchison meteorite.
The organic compounds, just the same, are very significant because many of these molecules yield important clues as to the nature of the protostellar disk—the type of chemistry which was prevalent before life took a foothold in our Solar System.
There have been skeptics—many of whom voiced legitimate concerns: contamination of the “rock” with terrestrial organics, ablation of meteor—resulting in significant alteration of the meteor, and “bad” handling processes by scientists and technicians. All the publications (three are listed below) which I have studied seemingly address the issues.
What does all of this mean? Molecular constituents that bear a resemblance to life’s constituents were “here” –in the protostellar disk, prior to us, prior to the dinosaurs, prior to the formation of our planet. That is a significant finding from a scientific point of view—almost (but not nearly close enough) as if we had found microbes on Mars, Europa, Enceladus, or Titan. Perhaps, it anything, this can serve as a rallying point for those of us who believe in science and its pursuits.
Publication reference list:
Schmitt-Koplin and others, 2010, Proceedings of the National Academy of Sciences.
Pizzarello and Shock, 2010, Cold Spring Harbor Perspectives in Biology.
(Cold Spring Harbor Perspect. 2010;2:a002105)
Callahan and others, 2011, Proceedings of the National Academy of Sciences.
Please note that you may have to pay for access—these references are copyrighted.