Mars is often referred to as a desert world, being bone-dry for the most part, with dust and sand blanketing most of the surface. Some regions are covered in vast sand dunes, reminiscent of deserts like the Sahara on Earth, only much colder. Gale crater, where the Curiosity rover landed in 2012, features extensive dune fields around the base of Mount Sharp, and the rover is now approaching some of them for the first time; their dark color makes them stand out starkly against the surrounding terrain. These dunes are also still active, meaning they are still mobile and shaped by the wind, not just old “fossil” (petrified) dunes which are no longer active.
geology
A complex world: Pluto discoveries include possible ice volcanoes, varied geology and weird spinning moons
Pluto is a small, cold world, but it is also turning out to be one of the most fascinating places in our Solar System – as reported this week at the American Astronomical Society’s Division for Planetary Sciences (DPS) meeting in National Harbor, Maryland, images and other data have revealed possible ice volcanoes and other surprisingly diverse geology as well as weirdly spinning moons.
Data from Spirit rover provides evidence for acid fog on ancient Mars
The various rover and lander missions on Mars have provided unprecedented glimpses into the planet’s past, including geological history and environmental conditions. In many ways, ancient Mars was similar to Earth, with abundant water and volcanic activity. Now, new research has revealed that there was also another related Earth-like phenomenon: acid fog.
Read MoreData from Spirit rover provides evidence for acid fog on ancient Mars
Curiosity rover confirms ancient lake(s) in Gale crater on Mars
Last week there was the exciting news that Mars still has flows of briny water occurring now, and this week there is more water-related news: additional findings from the Curiosity rover that the huge Gale crater was once a lake or series of lakes a long time ago. Curiosity had already found evidence that there used to be shallow lakes and streams in this area, but the new data confirms this and suggests that the lake(s) once filled Gale crater and were long-lasting, explaining the formation of Mount Sharp in the middle of the crater and also providing a potentially habitable environment for life.
Read MoreCuriosity rover confirms ancient lake(s) in Gale crater on Mars
Rosetta scientists answer question of how ‘rubber duck’ Comet 67P got its shape
Comet 67P/Churyumov–Gerasimenko, or 67P, has been the focus of intense study by the Rosetta spacecraft since 2014. One of the key mysteries scientists have been trying to figure out is how the comet became the odd “rubber duck” shape that it is, with its two distinct lobes. Now they think they have the answer: Comet 67P was formed by the collision of two other, separate comets which fused together to form its distinctive shape.
Read MoreRosetta scientists answer question of how ‘rubber duck’ Comet 67P got its shape