THE Red Planet turns blue in a photo taken to illustrate a typical Martian afternoon. Scientists at NASA coloured-up the image of the massive Endeavour crater in shades of blue so they could make out the details of its sandy ripples and dunes. The photo is made up of a series of shots taken by the Mars Rover Opportunity between 4.30pm and 5pm local time on March 9. A Mars day is 24 hours and 40 minutes but because it takes 687 days to go around the Sun, its year is almost two Earth years. The rover’s shadow is captured in the image, which was taken through a series of special filters. When the picture was taken the rover was enduring low-solar-energy weeks of the Martian winter. The late afternoon sun set the crater aglow and Opportunity waited for the right lighting to take its postcard shot. The four-billion-year-old impact crater is 14 miles across and its basin is shown in the upper half of the picture. Researchers hope to get Opportunity to one of the deposits of clay minerals detected in Endeavour’s rim by observations from orbit – more evidence of water on Mars. Solar-powered Opportunity’s original three-month mission ended eight years ago but it’s still providing fresh data.