More interesting things are being discovered at the mysterious grounds of our red neighbor, Mars. Just last week, NASA's Phoenix Spacecraft made a major discovery with evidence of ice underground. This week, a group of UC Berkeley researchers presented that it used to rain in Mars.

Actually, it's not exactly rain as in the exact same process we have here on earth. But because there used to be enough water in the atmosphere of Mars, it was possible enough for a light drizzle or dew to hit the ground. They found that the presence of water in the atmosphere came in the form of upwelling groundwater.

Today, the planet is too cold for water to exist in its liquid state, as was obviously seen from the ice discovery last week. However, it did indicate that during the Noachian epoch (Mars' earliest geological period) the planet did have enough atmospheric greenhouse gases to provide warm air and thus allow for lakes and rivers to flow.

What makes this new analysis on the planet's geological structure significant is that it suggests that things were not so different from Earth. Ronald Amundson, UC Berkeley professor of ecosystem sciences, who also led the study, said Mars' previous atmosphere can be likened to Earth's desert. "The Atacama Desert and the dry valleys of Antarctica are where Earth meets Mars. I would argue that Mars has more in common geochemically with these climate extremes on Earth than these sites have in common with the rest of our planet."

What's more:

It seems very logical that a dry, arid planet like Mars with the same bedrock geology as many places on Earth would have some of the same hydrological and geological processes operating that occur in our deserts here on Earth. Our study suggests that Mars isn't a planet where things have behaved radically different form Earth, and that we should look to regions like the Atacama Desert for further insight into Martian climate history.

The study's final version will be published in the journal of the International Geochemical Society, Geochimica et Comochimica Acta, on August. It will also be made available in an online version.