LONDON, June 27 (UPI) -- The Mars Odyssey spacecraft has detected the best evidence yet of water on Mars.
Barely a year ago, Mars Odyssey found signs the planet has reservoirs of underground ice near the south pole.
The BBC says scientists at NASA estimated there was enough ice to fill Lake Michigan twice. They said it might be merely the tip of the iceberg and it seems they were right.
New observations by Mars Odyssey and Mars Global Surveyor (another NASA probe that is mapping Mars) suggest the planet's north pole has about a third more underground ice than the south.
Beneath a shallow crust of dry soil, there appears to be a layer of permanently frozen ground that is up to 75 percent ice.
"If the conditions were warmer in the past, as they probably were, it may have led to the ice melting to form water which would be much more conducive to the presence of life," William Boynton, one of a team of Russian and American astronomers behind the discovery, told the BBC.
