Water once flowed beneath the surface of Mars - and the warmer, wetter ancient planet could have been considerably more hospitable for life. Scans by spectrometers on board the Mars Express and Mars Reconnaissance Orbiters have revealed 175 outcrops in Mars's Tyrrhena Terra mountains that are unmistakably 'weathered' by water. The rocks, found in craters, seem to have been 'carved' out from beneath the crust by asteroid impacts - and offer an insight into the planet's history, and what lies beneath the surface. The find proves water flowed beneath the surface of Mars for a 'long period', say the researchers.
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Rocky outcrops excavated from deep beneath surface by asteroid impacts
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Outcrops detected by Mars Express and Mars Reconnaissance orbiters
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Hints that water flowed deep beneath the surface in Mars's past
The spacecraft observations revealed hydrated silicate-bearing outcrops at 175 different sites in @placeholder, almost all of which are associated with ecrater walls and rims, and central uplifts inside craters.