When Mars was young, the planet was probably pretty cozy. It had a warm, thick atmosphere, and liquid water flowed across its surface. Yet the air quickly disappeared. And without a thick atmosphere, water couldn’t survive on the surface — it vaporized.
So far, though, scientists aren’t sure just how and why the atmosphere disappeared. But a new Mars mission should provide some answers.
The launch window opens tomorrow for MAVEN — Mars Atmosphere and Volatile Evolution. The craft will enter orbit around the Red Planet next September, then begin a one-year primary mission.
MAVEN’s altitude will vary from several thousand miles to less than a hundred. When it’s closest to the surface, its instruments will directly measure the composition of the upper atmosphere. And when it’s farthest, an ultraviolet camera will see the entire hemisphere, providing a global view of the atmosphere. The combination will help scientists understand how the atmosphere escapes into space, and the role the Sun plays in that process — leading to a more complete account of what happened to the ancient Martian air and water.
And Mars is climbing into better view each day. Right now, it’s high in the southeast at first light, shining like a bright orange star. It’s rising earlier each day, and by year’s end will be rising close to midnight. It’ll also shine about half again as bright as it does now, getting ready for a bright evening appearance next year.
Script by Damond Benningfield, Copyright 2013