The American space agency (Nasa) is celebrating 10 years of operation for its Opportunity rover on Mars.
The six-wheeled vehicle landed on the planet's Meridiani plains on 25 January, 2004, at 05:05 GMT.
It has since trundled 38.7km across the surface, studying the local geology and returning over 170,000 images to Earth.
How much longer the rover can continue working in Mars' harsh environment is unknown, but Nasa is confident it will keep rolling a while yet.
"The rover has some degraded components," explains John Callas, the manager of the agency's Mars Exploration Rover Project, which looks after "Oppy", as it is often called.
"The right-front steering actuator is jammed and no longer steers. The same wheel also shows elevated currents, the robotic arm has some arthritis, and two of the scientific instruments no longer function. But in the past year, almost nothing has changed in the health and status of the rover."
And it continues to deliver impressive research results.
To coincide with the anniversary, Science magazine has just published a paper detailing Opportunity's latest discoveries on the rim of the 22km-wide Endeavour Crater.
It has found evidence for clay minerals, which form in rocks that have been substantially altered by water.
In one place, these clays are of an iron-rich variety called smectite. In another location, Opportunity sees an aluminium-rich variety called montmorillonite.
They are contained in what are among the oldest rocks the rover has yet seen on the planet, probably four billion-plus years old.
It is further evidence, says the rover's deputy principal investigator, Ray Arvidson, that Mars was warmer and wetter in its distant past and had the potential, therefore, to support microbial life.
"If I were there back when this material was being emplaced and altered, and I had my summer house, this is where I would drill to get good drinking water," he jokes.
http://www.bbc.co.uk/news/science-environment-25878051
Topic: 10 Years on Mars (Read 1204 times)