Moon and Mars 
The Moon has a bright orange companion in the hours before sunrise tomorrow: the planet Mars. They're well up in the east at first light, with Mars just to the lower left of the Moon.
Several probes are studying Mars right now, with another scheduled for launch later this year. Scientists analyze the results of these missions, and prepare for new ones, in part by studying similar environments here on Earth. Known as Mars analogs, they include a river in Spain, the interior of Antarctica and an island off the Pacific coast of Canada.
But most Mars analogs are hot and dry -- great desert wastelands in the Americas. Even so, there's a little problem:
KUHLMAN: Most deserts are wet compared to Mars -- they're soaking wet compared to Mars.
Kim Kuhlman is a researcher with the Planetary Science Institute. She's visited several Mars analogs to study certain rocks that might be like some rocks on Mars -- rocks that could provide a home for microscopic organisms.
One of the places she's visited is the most Mars-like of all the Mars analogs: the Atacama Desert of Chile.
KUHLMAN: The Atacama is considered the closest thing we have to a Mars environment -- it's so very, very dry. We work at the hyper-arid core of the Atacama. It rains very, very, very infrequently there -- millimeters every decade, if that. It looks just like Mars. There is no vegetation whatsoever. The sky is blue, but other than that it looks like Mars.
More about the study of Mars analogs tomorrow.
Script by Damond Benningfield, Copyright 2011