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Mars orbiter tracks down rover

NASA / JPL / Univ. of Ariz.

An image from NASA's Mars Reconnaissance Orbiter shows the Opportunity rover on the rim of Santa Maria Crater (indicated by arrow) with the tracks of its wheels extending toward the left edge of the frame (visible as a faint reddish line).

Two heads are better than one, even if the "heads" happen to be the cameras built into two different space probes. Here's a fresh picture from the High Resolution Imaging Science Experiment, a camera on NASA's Mars Reconnaissance Orbiter, which shows the Opportunity rover as a speck perched on the rim of a 300-foot-wide Martian crater known as Santa Maria.

Amazingly, the tracks of the rover can be seen trailing off to the left across the plains of Meridiani Planum.

NASA often uses orbiters and rovers as a double team to identify sites of interest from the air and then investigate them on the ground. For example, the orbiter's CRISM spectrometer indicates that there is hydrated sulfate at Opportunity's location, which suggests that liquid water once flowed through the area. The rover is currently taking a closer look at the minerals to study their composition in detail. The same double team will come in handy when Opportunity travels to an even bigger hole in the Martian ground, the 14-mile-wide Endeavour Crater.

Opportunity has been going strong on Mars for more than seven years, and Mars Reconnaissance Orbiter is also in it for the long haul. NASA notes that Thursday marks the fifth anniversary of the orbiter's entry into Martian orbit. It seems like yesterday ... but since that time, MRO has sent back 131 trillion bits of data, including more than 70,000 images that are cataloged on the HiRISE website. That's more data than all other interplanetary missions combined.

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