A CHANCE ENCOUNTER: WHAT A PASSING COMET CAN TEACH US ABOUT MARS

摘要

One renegade comet performed a fly-by of Mars last fall, and NASA's newest Mars orbiter arrived just in time for the show. The Mars Atmosphere and Volatile EvolutioN (MAVEN) satellite entered orbit around Mars on September 21, 2014. Less than a month later, on October 19, comet Siding Spring made a tight pass by the red planet, bombarding the atmosphere with debris and providing scientists with exciting new data. The MAVEN mission, led by researchers at the University of Colorado-Boulder (CU) in conjunction with NASA, Berkeley, and Lockheed Martin, is out to solve a cosmic whodunit. Satellite images clearly show parched river channels and lakebeds on Mars' surface. The rover missions, which explore the Martian surface, have confirmed the presence of rocks and minerals that could only have formed in the presence of flowing water. However, the image of liquid water on Mars stands in drastic contrast to the dry, frigid planet we know.