12185Meteorite Contains Extraterrestrial Organic Molecules Never Found Before
- Sep 11, 2013URL to an interesting post from The Daily GalaxyChris
Warning! Things in the rear-view mirror are weirder than they seem."A sonic boom heard in California last year had an out-of-this world origin as ”a large meteoric event” according to NASA’s Meteoroid Environment Office. Scientists now estimate the blast measured in near 5 kilotons or roughly 1/3 the power of the atomic bomb dropped on Hiroshima, Japan during World War II.Bill Cooke of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center, estimates the object was about the size of a minivan, weighed in at around 154,300 pounds.Meteorite hunters found fragments of the rock, identified by the "fusion crust" that forms when it burns in the atmosphere. NASA and the SETI Institute in Mountain View, California, also mobilised a search team of about 30 scientists to search for the small black rocks.
The meteorite turned out to be a very rare type of rock called CM chondrite, which makes up less than 1 per cent of the meteorites that fall to Earth. According to Bill Cooke of NASA's Meteoroid Environment Office at the Marshall Space Flight Center in Huntsville, Alabama, it is not clear whether it is rare because it easily burns up in the atmosphere or there are just fewer of these rocks in space.
The meteorite has now led to an important discovery concerning the possible inventory of molecules available to the early Earth. Scientists led by Sandra Pizzarello, a research professor in ASU's Department of Chemistry and Biochemistry, found that the Sutter’s Mill meteorite contains organic molecules not previously found in any meteorites. These findings suggest a far greater availability of extraterrestrial organic molecules than previously thought possible, an inventory that could indeed have been important in molecular evolution and life itself.
Coincidentally, Sutter’s Mill is also the gold discovery site that led to the 1849 California Gold Rush. Detection of the falling meteor by Doppler weather radar allowed for rapid recovery so that scientists could study for the first time a primitive meteorite with little exposure to the elements, providing the most pristine look yet at the surface of primitive asteroids.
“The analyses of meteorites never cease to surprise you ... and make you wonder,” explains Pizzarello. “This is a meteorite whose organics had been found altered by heat and of little appeal for bio- or prebiotic chemistry, yet the very Solar System processes that lead to its alteration seem also to have brought about novel and complex molecules of definite prebiotic interest such as polyethers.”
Pizzarello and her team hydrothermally treated fragments of the meteorite and then detected the compounds released by gas chromatography-mass spectrometry. The hydrothermal conditions of the experiments, which also mimic early Earth settings (a proximity to volcanic activity and impact craters), released a complex mixture of oxygen-rich compounds, the probable result of oxidative processes that occurred in the parent body. They include a variety of long chain linear and branched polyethers, whose number is quite bewildering.