January 3, 2013
Martian Meteorite Contains More Water Than Any Others Found To Date
Lee Rannals for redOrbit.com - Your Universe Online
Researchers have identified a new class of Martian meteorite that they believe originated from Mars' crust.The team wrote in Thursday's issue of Science Express that this new meteorite contains more water than any other Martian meteorite ever found. The sample is the only one found that dates back to 2.1 billion years ago, which is an early era on Mars known as the Amazonian.
The meteorite, known as Northwest Africa (NWA) 7034, shares several similarities with another Martian meteorites known as SNC. These meteorites are the only samples from Mars that scientists have been able to study, but their exact point of origin on the planet remains unknown.
"The texture of the NWA meteorite is not like any of the SNC meteorites," said Andrew Steele, who led the carbon analysis at the Carnegie Institution´s Geophysical Laboratory. "It is made of cemented fragments of basalt, rock that forms from rapidly cooled lava, dominated with feldspar and pyroxene, most likely from volcanic activity. This composition is common for lunar samples, but not from other Martian meteorites."
He said that the meteorite's unique chemistry suggests that it came from the Red Planet's crust, making it the first link of any meteorite to the crust.
"Our carbon analysis also showed that the meteorite likely underwent secondary processing at the Martian surface, explaining the macromolecular organic carbon," Steele added.
Carl Agee at the University of New Mexico, lead author of the project, said the basaltic rock in this meteorite is consistent with the crust or upper mantle of Mars based on findings from recent Martian rover and orbiter missions.
"Our analysis of the oxygen isotopes shows that NWA 7034 is not like any other meteorites or planetary samples," Agee said. "The chemistry is consistent with a surface origin and an interaction with the Martian atmosphere."
He added that the abundance of water suggests that the meteorite interacted with the Martian surface during the Amazonian era.
"Perhaps most exciting is that the high water content could mean there was an interaction of the rocks with surface water either from volcanic magma, or from fluids from impacting comets during that time," Steele said. “It is the richest Martian meteorite geochemically, and further analyzes are bound to unleash more surprises."