APOD has a celebratory post up today – celebrating seven years on Mars by the amazing Opportunity explorer. Designed for a mission of 90 days, it is still in nearly perfect condition seven years later. It has now logged over 15 miles (27 km) of roving over the Martian surface, far more than its designers ever dreamed of. It's also had its share of good luck: unexpectedly common dust devils have cleaned the accumulated dust off its solar panels on several occasions. Without these lovely dust storms, Opportunity's solar panels would long ago have been blocked.
Opportunity's sibling rover Spirit is also still operational, but it has suffered more component failures (especially its wheels) and is now stuck in one place. Nevertheless, it's still doing yeoman science work every day.
Click on the image below to see it greatly magnified, or see it on
APOD...
