Over the decades, Mars has been at the center of many controversies, some of which have concerned the question of life. The most famous is the idea that an ancient civilization built a network of canals across the Red Planet. And another controversy is still playing out: the possibility that microscopic organisms are emitting methane into the Martian atmosphere.
In recent years, a couple of ground-based studies detected small amounts of methane in the atmosphere. So did the Mars Express spacecraft, which entered orbit around the planet 10 years ago this week.
Most of the methane in our atmosphere is produced by living organisms. So the discovery on Mars suggested the possibility of life — perhaps in the form of microscopic organisms below the surface. But methane can also come from volcanoes and other processes, so life was far from a solid conclusion.
It got less solid this year. Observations by the Curiosity rover on the Martian surface found no methane in the air around its landing site. Scientists are using other instruments on the rover to try to confirm the finding, while other groups re-examine the detection by earlier experiments — an effort to solve the controversy over methane in the Martian atmosphere.
Mars is in great view early tomorrow. At first light, it’s close to the upper right of the Moon, and looks like a bright orange star. The true star Spica is about the same distance to the lower left of the Moon.
Script by Damond Benningfield, Copyright 2013
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