Interglacial period
The new studies suggest that Mars is currently in an interglacial period. As the planet tilts closer to the sun, ice near the equator is expected to vaporize.

In a third paper, additional detail is provided on a previous announcement of a frozen chunk of water - roughly the size of the North Sea - that formed in the last five million years near the Martian equator. The area is thought to have been flooded by liquid water carried along by volcanic eruptions in a region called Cerberus Fossae.

"The three papers provide an overwhelming case for new thinking about recent geological activity on Mars," writes Baker in an analysis of the work.

Cataclysmic flooding
Baker said the findings support a 1991 hypothesis, then considered outrageous, that Mars has experienced episodes of cataclysmic flooding in modern times. Water is thought to have formed temporary seas, but researchers had long assumed it all evaporated into the thin Martian air.

Story continues below ↓

advertisement | your ad here

Many scientists now agree that much of the water remained.

"The evidence from HRSC for recent aqueous activity suggests that the water is still present, as ice on the ground and water deep beneath the surface," Baker said.

In early May, Mars Express will deploy a radar instrument that should be able to detect subsurface water and ice several miles down.

"Evidence from the latest pictures indicates that the water will surely be there," Baker said.

Where there is water, there could be life. Many investigations on Earth have turned up extremophiles -- microbes living in frigid conditions, thriving in extremely salty water, and gathering around volcanic vents. Last month scientists announced the discovery of bacteria that had survived in a state of frozen suspension for 32,000 years.

"We're now seeing geological characteristics on Mars that could be related to life," Head said. "But we're a long way from knowing that life does indeed exist. The glacial deposits we studied would be accessible for sampling in future space missions. If we had ice to study, we would know a lot more about climate change on Mars and whether life is a possibility there."

< Prev | 1 | 2