On Mars: It's Curiosity's moment to shine, but MAVEN is in the works (+video)
In 2014, Curiosity and MAVEN are slated to team up to help scientists unravel the mystery behind Mars' vanishing atmosphere: How did a wet, warm planet lose that thin layer that can preserve the building blocks of life?
When NASA's latest Mars rover Curiosity survived its "seven minutes of terror" plunge through the planet's atmosphere in early August and phoned home to say all was well, the mission's scientists and engineers were ecstatic. They had put themselves in a good position to see if their target, Gale Crater and its three-mile-high central summit, might at one time have hosted an environment suitable for life.Skip to next paragraph
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But the atmosphere through which Curiosity descended also plays a key role in determining the planet's hospitality. Engineers and technicians are now assembling MAVEN, an orbiter slated for launch in November 2013 that will unravel the mystery of Mars' vanishing atmosphere.
Combined with key measurements Curiosity will take at the surface, MAVEN's measurements at the top of Mars' atmosphere are expected to allow researchers to reconstruct a history of the atmosphere – including the rate at which the planet has lost water over its 4.6-billion-year history.
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Water is a key ingredient for the emergence of organic life. One of the questions Curiosity will help answer: Did water ever collect in Gale Crater? MAVEN is asking: Where did any surface water ultimately go?
Moreover, a thick atmosphere is one line of defense against cosmic rays, as well as extreme forms of ultraviolet radiation and energetic particles, which stream from the sun as "solar wind" and flood Mars' immediate surroundings during powerful solar storms. These forms of radiation can make for a bad day at the office for organisms on a planet's surface or for the complex organic molecules on the surface that could give rise to simple forms of life.
Scientists have been interested in making MAVEN-like measurements at the red planet since the 1980s, says Bruce Jakosky, the mission's lead scientist.
Scientists had long known that Mars' atmosphere was thin – about 1 percent as dense as Earth's atmosphere. But it took the Pioneer-Venus orbiter in 1978 to show that researchers could record the processes eroding another planet's atmosphere as they happened.
Researchers realized these were important measurements to make at Mars as well, says Dr. Jakosky, a researcher working at the interface of planetary geology and astrobiology at the University of Colorado at Boulder.
"Without going and measuring what's actually happening, you can't have any hope of understanding" the unique mix of factors that turned Mars from what many scientists hold as a wet, warm planet early in its history to the dry, radiation-bathed surface the planet presents today.
Eight sensors on the orbiter will allow scientists to tackle the atmosphere's history in three broad ways.