space | A giant slab of ice as big as California and Texas combined lurks just beneath the surface of Mars between its equator and north pole, researchers say.
This ice may be the result of snowfall tens of millions of years ago on Mars, scientists added.
Mars is now dry and cold, but lots of evidence suggests that rivers, lakes and seas once covered the planet. Scientists have discovered life virtually wherever there is liquid water on Earth, leading some researchers to believe that life might have evolved on Mars when it was wet, and that life could be there even now, hidden in subterranean aquifers. [Photos: The Search for Life on Mars]
The amount of water on Mars has shifted dramatically over the eons because of the Red Planet's unstable obliquity — the degree to which the planet tilts on its axis of rotation. Unlike Earth, Mars does not have a large moon to keep it from wobbling, and so the direction its axis points wanders in a chaotic, unpredictable manner, regularly leading to ice ages.
Although researchers have long known that vast amounts of ice lie trapped in high latitudes around the Martian poles, scientists have recently begun to discover that ice also is hidden in mid-latitudes, and even at low latitudes around the Martian equator.
Learning more about past Martian climates and where its water once was "could help us understand if locations on Mars were once habitable," study lead author Ali Bramson, a planetary scientist at the University of Arizona in Tucson, told Space.com.
To look at ice hidden beneath the Martian surface, Bramson and her colleagues focused on strange craters in a region called Arcadia Planitia. This area lies in the mid-latitudes of Mars, analogous to Earthly latitudes falling between the U.S.-Canadian border and Kansas.
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