September 11, 2013
Sutter’s Mill Meteorite Provides Evidence Of Molecules Available To The Early Earth
April Flowers for redOrbit.com - Your Universe Online
Researchers from Arizona State University (ASU) have made an important discovery about the possible inventory of molecules available to the early Earth.
Sandra Pizzarello, a research professor in ASU's Department of Chemistry and Biochemistry, led the team in examining the Sutter's Mill meteorite - which exploded in a blazing fireball over California last year - to find that it contains organic molecules not previously found in any meteorites. These findings, published in Proceedings of the National Academy of Science, show that there was a far greater availability of extraterrestrial organic molecules than previously thought possible. This new inventory could have been important in molecular evolution and life itself.
Pizzarello's team was comprised of geologist Lynda Williams, NMR specialist Gregory Holland and graduate student Stephen Davidowski, all from ASU.
Sutter's Mill, California, is also the site of the original gold discovery that led to the 1849 California Gold Rush. Doppler weather radar detected the falling meteor traveling at about 64,000 miles per hour over the Sierra Nevada, which allowed for rapid recovery by scientists and the chance to study a primitive meteorite with little exposure to the elements. This provided the most pristine look yet at the surface of primitive asteroids.
“The analyses of meteorites never cease to surprise you ... and make you wonder,” explained 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.”
The meteor fragments were hydrothermally treated, then the team detected the compounds released by gas chromatography-mass spectrometry. The experiments mimicked early Earth environments - proximity to volcanic activity and impact craters - with hydrothermal conditions. These conditions released a complex mixture of oxygen-rich compounds, the probable result of oxidative processes that occurred in the parent body. These compounds include a variety of long chain linear and branched polyethers, whose number is quite bewildering.
This discovery opens the door for further debate about whether the delivery of organic compounds produced in extraterrestrial environments to the early Earth by comets and meteorites might have aided the molecular evolution that preceded the origins of life.
This is by far not the first time the Sutter's Mill meteorite has been studied. In 2012, redOrbit's Lee Rannals reported that a team of scientists from the American Museum of Natural History studied the Sutter's Mill meteorite, finding that it is an unusual example from a rare group known as carbonaceous chondrites. These types of meteorites are some of the oldest material in the solar system.
"Several fragments were sent to laboratories around the world for analysis of the meteorite’s mineralogy and structure. The Sutter’s Mill meteorite was classified as a CM chondrite, C standing for carbonaceous–high in carbon content–and M standing for the group’s type specimen," Rannals reported.