Stunning new images of Mars have been released by Nasa, including close-ups of its larger moon Phobos.
The one we show here is a general colour view of the tiny world – thought to be a captured asteroid, with its fascinating craterlets and grooves.
But Nasa also released a 3D image, viewable if you have blue-and-red glasses, taken by the HiRise camera on the Mars Reconnaissance Orbiter.
Rather than using two cameras to take the twin exposures necessary, scientists simply took two photos ten minutes apart to achieve a similar effect.
The Phobos pictures reveal a phenomenon called Marsshine which is the equivalent to Earthshine on the Moon. Just as sunlight reflected back from the Earth illuminated the dark disk of a “New” Moon, so the light from Mars lights up craters on Phobos that would otherwise be in darkness.
Professor Alfred McEwen, HiRise principal investigator at the Lunar and Planetary Laboratory at the University of Arizona, said: “Phobos is of great interest because it may be rich in water ice and carbon-rich materials.”
Another amazing picture from HiRise shows sand dunes that look so perfectly sculpted that you could be forgiven for thinking they were designed by artistic aliens.
But the dunes, within the Hellespontus region of Mars, are simply the result of powerful winds blowing from west to east (left to right in the picture) according to the experts.
Prtevious wonderful images from Mars Reconnaissance Orbiter have included a look back at the Earth and Moon plus clear pictures that put a damper on claims that fresh water is still flowing on Mars.