The first humans lived in caves. Now it seems very likely that the first humans on Mars will do the same. After being studied Martian geography allows us to look for the right kind of caves. "At least two regions, the Tharsis rise and the Elysium rise, contain volcanic features which may be suitable locations for caves," said Kaj Williams from NASA's Ames Research Center in Mountain View, California. The analysis showed that caves in these regions might contain a ready supply of water, in the form of ice. The caves formed in lava tubes are common in Mars and they can become home for the first human colonists. These caves were created when ancient lava flows solidified at the surface, while lava inside drained away.
The existence of ice in these caves has been suggested before, but Williams and colleagues have taken the idea one step further by using a computer model to find out exactly how ice might build up inside them. They also looked at how long it might last.
The team represented their cave as a box 10 metres square by 8 metres high, with a single small opening to the atmosphere in the roof. They found that during the Martian day, warm, buoyant air would not enter the cool cave, saving the ice from melting. At night, as the outside air cooled, it would sink into the cave and bring in water vapour that condensed as frost onto the already icy walls.
The model showed that the ice would be stable, lasting for up to 100,000 years. Ice formed on the walls of Martian caves would be stable, lasting for up to 100,000 years and could prove a source of water for habitation and fuel, and could also provide shelter from dangerous solar radiation. Astronauts would find the caves excellent homes, says co-author Brian Toon of the University of Colorado, Boulder. "Perhaps we could call them 'cavenauts'."
