Today marks the start of the 9th year that NASA’s Opportunity rover has been active on Mars.

Launched back in 2003, and landing on January 25th 2004, Opportunity had an operational expectation of 90 sols (a sol being a Martial day, which is a bit over 24 hours and 39 minutes). That’s 92.2 Earth days. Today marks day 2922. In that time it’s covered 34.4 km.

Opportunity is one of a pair, with the older brother Spirit (which landed on Mars about 3 weeks before Opportunity) now incommunicado since 2010. These rovers have so vastly exceeded expectations that they must surely go down in history as one of the best value space missions ever conducted. Although capable of stunning panoramic photography, these rovers are much more than just a camera on wheels. Equipped with a range of spectrometers, they are able to perform geochemical identifications of the samples they investigate.

It was through the use of these spectrometers that Opportunity identified gypsum in the Homestake mineral vein last year – evidence that Mars has had flowing groundwater in its past.

And Opportunity is not done yet. Although Spirit suffered power loss from accumulated dust on its solar panels, Martian winds have proven kinder to Opportunity. Now sitting out the Martian winter, the little rover that could is heading to its next target this summer. As might be expected, however, the rover is not on tip-top form. Although not suffering the undercarriage problems of Spirit, the age of the rover is bringing a rather more fundamental problem.

The Mössbauer spectrometer, which identifies iron-containing minerals, uses radiation from cobalt-57 in the instrument to elicit a response from molecules in the rock. The half-life of cobalt-57 is only about nine months, so this source has diminished greatly. A measurement that could have been made in less than an hour during the rover’s first year now requires weeks of holding the spectrometer on the target.

Now there’s a problem they didn’t anticipate in the project planning for a 90 day mission.

So, it being Burns night, I ask you all to raise a wee dram to one of the most exceptional geologists in the solar system.

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