Iron meteorites could signal Mars water

London, June 5 (ANI): The rover Opportunity has found six new iron meteorites on Mars, which may reveal how much water they have come into contact with since they landed on the planet millions or billions of years ago.

The rovers Spirit and Opportunity have previously found three iron meteorites, whose shiny, metallic appearance makes them stand out against the dusty Martian surface.

Now, according to a report in New Scientist, Opportunity has turned up six other candidates on a Martian plain called Meridiani Planum, all of which appear to be related to each other.

Instruments on the rover, including its Mossbauer spectrometer, show the rocks are stony, but also contain iron-bearing minerals present in meteorites found on Earth, such as kamacite and troilite.

Because they contain iron, the six new rocks may reveal how much water they have come into contact with since they landed on the planet millions or billions of years ago.

"Imagine finding an old, rusty car in the desert. That is going to tell you something about the exposure to water there," said James Ashley of Arizona State University in Tempe.

So far, no major signs of rust have been found, but even slight amounts of rust would hint at the alteration by water - in liquid form, and perhaps even in the form of water vapour or ice.

"The rocks are hypersensitive indicators of water exposure, and so may help us address some of Mars's more subtle climate behaviour in recent epochs," said Ashley.

"I've been very excited about the prospects of finding meteorites at the Opportunity landing site because it is the perfect setting for it - an ancient surface with very few Mars rocks," he added. "In this sense, it is similar to Antarctic meteorite fields where few Earth rocks are to be found," he further added.

The rocks may be so-called "impact breccias" - a mixture of both the impactor that created Victoria Crater and the Martian crust that it hit.

"If this is true, then they may have simply weathered out of the blanket of ejected material surrounding the crater and are now resting on the surface," said Ashley. (ANI)