by Jim Nintzel
Now up for your viewing pleasure: A fresh batch of Mars images from the UA Lunar and Planetary Lab's HiRISE camera
Speaking of Mars: We ran into Peter Smith, the principal investigator of the LPL's Phoenix Mars Mission, last week. He said they were still listening to see if their plucky robot survived the harsh winter on the Arctic plains of Mars, but they hadn't heard anything yet.
He also mentioned a recent story we missed: The LPL is one of three finalists in a competition for a NASA space mission. The plan: Drop a robotic spacecraft named OSIRIS-REx onto an asteroid, take same samples and snapshots, and come back home to earth. How cool is that?
OSIRIS-REx will usher in a new era of planetary exploration. For the first time in space-exploration history, a mission will return a pristine sample of a carbonaceous asteroid.
The mission executes precise spacecraft navigation to the surface of the asteroid, thoroughly characterizes the asteroid and the sample site, acquires a significant quantity of
pristine regolith and returns these samples safely to Earth for detailed analyses.
By the way: If you're wondering what the Mars photo above is all about, HiRISE team member Colin Dundas tells us:
This image shows a stack of layers on the floor of an impact crater roughly 30 kilometers across. Many of the layers appear to be extremely thin, and barely resolved.
In broad view, it is clear that the deposit is eroding into a series of ridges, likely due to the wind. Below the ridges, additional dark-toned layered deposits crop out. These exhibit a variety of textures, some of which may be due to transport of material.
The light ridges are often capped by thin dark layers, and similar layers are exposed on the flanks of the ridges. These layers are likely harder than the rest of the material, and so armor the surface against erosion. They are shedding boulders which roll down the slope, as shown in the subimage. Although these cap layers are relatively resistant, the boulders do not seem to accumulate at the base of the slope, so it is likely that they also disintegrate relatively quickly.
The subimage itself is 250 meters wide. The light is from the left. Boulders are visible on the slopes of the ridges along with thin dark layers including the cap layer, but they are absent on the spurs where the resistant cover has been eroded. This demonstrates that the boulders come only from the dark layers, and are not embedded in the rest of the deposit.