Another odd but beautiful image of Mars, showing a cone-shaped hill with sand dunes wrapping around it. The formation is in the Ganges Chasma region, and the image was taken by the HiRISE camera on the Mars Reconnaissance Orbiter. Mars has a lot of diverse geology, and this is another good example of that. Original images are here.
The Martian rover Opportunity has become famous for its amazing longevity, but it is not the only one; orbiting spacecraft also usually enjoy long lifespans, and today the Mars Reconnaissance Orbiter is celebrating its 10th year exploring Mars from above. It has helped to revolutionize our understanding of Mars and its complex geological history as well as, of course, sending back thousands of incredible high-res images of the Martian surface.
In a finding that is sure to fuel the ongoing debate about possible life on Mars, NASA announced yesterday the confirmation that intriguing seasonal dark streaks running down Sun-facing slopes are indeed flows of liquid water. The water is salty (briny), but just the fact that it is current liquid water, albeit transient and in relatively small amounts, is still big news.
The question of how Mars changed from a once wet world to the much colder and drier one we see today is one that scientists have been trying to answer for a long time. There is plenty of evidence that Mars use to have lakes and rivers, and perhaps even oceans. But what happened to change that? Now, a new study might bring us one step closer to solving this conundrum.
The fact that Mars used to have large amounts of liquid water on its surface is pretty much accepted among scientists, but there is still the question of how long that water lasted. How long ago was it still present? A billion years? A few million? New evidence based on data from the Mars Reconnaissance Orbiter (MRO) suggests that water was still on the surface within the past million years, perhaps even as recently as 500,000 years ago, which is indeed recent, geologically speaking.
When the topic of ice on Mars comes up, the first thing that usually comes to mind are the polar ice caps which are prominent even in small telescopes. There is, however, ice elsewhere on the planet as well, such as beneath the surface in the mid-latitudes, covered by dust. Now, a new study has revealed the extent of these subsurface glaciers and the amount of frozen water they contain.
This is interesting, a recent HiRISE photo from the Mars Reconnaissance Orbiter spacecraft showing an oval pit or crater with an opening in the bottom (cropped here from one of the larger images) near Galaxias Chaos on Mars. The opening is also oval, and you can see some sand dunes on the bottom. How did it form? More images are available here.
Whether or not Mars once had an ocean has been a subject of much debate for many years. There is substantial evidence pointing toward the possibility, but no “smoking gun” yet. Now, a new discovery from scientists at the California Institute of Technology (Caltech) is fueling that debate again – an ancient delta that appears to have emptied into the hypothetical ocean in the northern hemisphere.
Mars is famous for its duststorms, which can grow big enough to cover the entire planet. But did you know that it also has snowstorms? These storms can dump a lot of snow on the north polar cap during the bitterly cold winter, and now scientists say they can more accurately forecast them, it was reported yesterday, which would aid any future rover missions in these areas.