Geologists led by Dr Lydia Hallis from the University of Hawaii have examined a meteorite that formed on Mars more than 1 billion years ago to determine if conditions were ever right on the planet to sustain life.
The meteorite, called Miller Range 03346 nakhlite (MIL 03346), was recovered in 2003 in the Miller Range of Antarctica. About the size of a tennis ball and weighing in at one-and-a-half pounds, MIL 03346 was one of hundreds recovered from that area.
Although the new study is not specifically solving the mystery, it is laying the groundwork for future researchers to answer the age-old question.
“The problem is that most meteorites that originated on Mars arrived on Earth so long ago that now they have characteristics that tell of their life on Earth, obscuring any clues it might offer about their time on Mars,” said Prof Michael Velbel from Michigan State University, co-author of the paper published in the journal Geochimica et Cosmochimica Acta.
“These meteorites contain water-related mineral and chemical signatures that can signify habitable conditions. The trouble is by the time most of these meteorites have been lying around on Earth they pick up signatures that look just like habitable environments, because they are. Earth, obviously, is habitable. If we could somehow prove the signature on the meteorite was from before it came to Earth, that would be telling us about Mars.”
Specifically, Dr Hallis’ team found mineral and chemical signatures on MIL 03346 that indicated terrestrial weathering – changes that took place on Earth. The identification of these types of changes will provide valuable clues as scientists continue to examine the meteorites.
“Our contribution is to provide additional depth and a little broader view than some work has done before in sorting out those two kinds of water-related alterations – the ones that happened on Earth and the ones that happened on Mars,” Prof Velbel said.
“Past examinations of meteorites that originated on Mars, as well as satellite and Rover data, prove water once existed on Mars, which is the fourth planet from the Sun and Earth’s nearest Solar System neighbor.”
“However, until a Mars mission successfully returns samples from Mars, mineralogical studies of geochemical processes on Mars will continue to depend heavily on data from meteorites,” Prof Velbel concluded.
Bibliographic information: Julie D. Stopar et al. 2013. Element abundances, patterns, and mobility in Nakhlite Miller Range 03346 and implications for aqueous alteration. Geochimica et Cosmochimica Acta, vol. 112, pp. 208–225; doi: 10.1016/j.gca.2013.02.024