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Comet C/2011 L4 (PANSTARRS)

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Comet C/2012 S1 (ISON)

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Web Extras

Revealing the Red Planet's secrets

The High Resolution Imaging Science Experiment onboard the Mars Reconnaissance Orbiter continues to amaze scientists with its detailed images.
By Richard Talcott
Published: December 19, 2007
Since it reached its final orbit around Mars in late 2006, the Mars Reconnaissance Orbiter (MRO) spacecraft has been studying the Red Planet in unprecedented detail. It has found that water may not have been quite as ubiquitous on ancient Mars as many scientists previously thought. Images of the boulder-strewn northern lowlands argues against the possibility a vast ocean once existed there. And several other locations show more signs of flowing lava than flowing water.
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