NASA's Mars Exploration Rover Opportunity landed on Mars eight years ago today on what was expected to be just a 90 day mission, and while twin rover Spirit has remained silent since March 2010, Opportunity continues to rove across the red planet's surface.

Greeley Haven is Opportunity's current workplace, an outcrop with a Sun-facing slope that will allow the aging rover to soak up solar power during its fifth Martian winter. Within reach of the rover's robotic arm are plentiful sites for scientific investigation, including inspection of mineral compositions and textures within the outcrop. A full-circle colour panorama is also on the schedule along with a radio science experiment that will record information about the tiny wobbles in Mars' rotation to provide insight into the planet's interior.

The rover's winter worksite lies on the rim of 22 kilometre-wide Endeavour Crater, which it reached nearly six months ago having traversed 21 kilometres over three years from smaller Victoria Crater.

Although Spirit ceased communications in March 2010, both rovers have made important discoveries about wet environments on ancient Mars. Opportunity now enters its ninth year of exploration and despite dust-covered solar panels, shows no signs of giving up yet.