A ridge in Mars' Terra Meridiani shot by the Mars Reconnaissance Orbiter. NASA says that the stream which formed this ridge must have been ancient as the ridge is buried by brighter rocks, which are themselves very old.
New images of Mars include scenes of rimless pits, mud volcanoes and other features. In this enhanced image, you can see the inside of a rimless pit.
Artist's conception of planet GJ 1214b, with two hypothetical moons as it orbits a red dwarf star. The planet is about 40 light-years from Earth.
South polar region of Saturn's moon Enceladus photographed by NASA's Cassini spacecraft
High-altitude layer of sulphur dioxide discovered by ESA's Venus Express.
The Mars Hand Lens Imager camera on Curiosity photographed these grains from a sand dune near Christmas Lake, Ore.
The Mars Reconnaissance Orbiter, currently in orbit around the Red Planet, photographed these dark rippled dunes the Proctor Crater.
The Stratospheric Observatory for Infrared Astronomy, or SOFIA, waiting on the tarmac during nighttime telescope operations at NASA's Dryden Aircraft Operations Facility.
The spiral galaxy, M33 in the northern constellation Triangulum, is believed to be over 50,000 light-years in diameter.
The Hartley 2 star cluster photographed up close by a probe sent up from Earth.
The Martian Moon Phobos photographed from the Mars Express. Phobos is a heavily cratered and barren moon, with its largest crater located on the far side. What's especially interesting here is that Phobos' orbit around Mars is continually decaying and scientists say it will likely break up with pieces crashing to the Martian surface in about 50 million years.
A "tiger stripe" fissure on Saturn's moon Enceladus, courtesy of NASA's Cassini spacecraft.
Artist's Concept of SOHO spacecraft observing the sun.