A giant patch of frozen water has been pictured nestled within an unnamed impact crater on Mars. Cool photo.
The photographs were taken by the High Resolution Stereo Camera on board Mars Express, the European Space Agency probe which is exploring the planet.
The ice disc is located on Vastitas Borealis, a broad plain that covers much of Mars’ far northern latitudes.
The existence of water on Mars raises the prospect that past or present life will one day be detected.
It also boosts the chances that manned missions can eventually be sent to the Red Planet.
The highly visible ice is sitting in a crater which is 35 km (23 miles) wide, with a maximum depth of about two km (1.2 miles).
Scientists believe the water ice is present all year round because the temperature and pressure are not sufficient to allow it to change states.
Researchers studying the images are sure it is not frozen carbon dioxide (CO2), because CO2 ice had already disappeared from the north polar cap at the time the image was taken.