18 December 2008
A long walk to Circuit City and a few dollars later, I am now the proud owner of a new AC adaptor! Luckily today is all posters so I have some time to post a summary of yesterday’s events.
Yesterday was a day chock full of Martian goodness, and it started off bright and early with a summary of the results from the Mars Reconaissance Orbiter’s primary mission. MRO has returned about 74 terabytes of science data to earth, which is more data than all the other Mars missions EVER combined.
The Context Camera (CTX) has mapped 40% of the surface of Mars at a resolution of 6 meters per pixel, which just boggles my mind. That used to be “high resolution” data, but now it’s just context for HiRISE and CRISM. Some of the highlights from CTX include the discovery of dozens of fresh craters from impacts that occured during the mission, and CTX images show that much of the Martian surface is cris-crossed with “inverted” channels. These form because at the bottom of a river, larger rocks tend to collect. Then when the river dries up and the terrain erodes, the river-bottom is “armored” by those rocks, so it resists erosion and becomes a ridge instead of a trough. CTX can also be used to make 3D anaglyphs, like this (scaled-down) one of the Gale crater landings site and traverse, which I have been studying. The full mosaic that I’m using is made up of a dozen or so CTX images and is about 40,000×40,000 pixels!
CRISM has mapped 63% of the surface at low (200 m per pixel) resolution, plus thousands of high-res observations. They have found evidence for hydrated minerals all over the place (though often in very small outcrops). These include the famous phyllosilicates (clays), sulfates, hydrated silica, and even some of the elusive carbonates (though not enough carbonate to explain where the thick CO2 atmosphere went).
HiRISE reported that they have taken 9549 images, and a grand total of 8,212 gigapixels of data. I was especially interested by their report that some fresh craters at mid-latitudes seem to have punched through the rocky, dusty surface and uncovered ice! They are pretty sure it is ice because in the biggest craters it shows up in CRISM, and it fades over time as you would expect for sublimating ice.
SHARAD, the radar sounder reported their mapping of the ice caps, including the puzzling fact that despite the huge amount of ice, the crust doesn’t seem to be bowed down, indicating that Mars has a colder and thicker crust than expected. SHARAD also was recently in the news for proving that there are icy glaciers on Mars. They also showed that some things that people thought were ice are actually not, such as this image from Cerberus Palus:
MARCI, the fisheye lens that maps the entire Martian surface every day and acts as a weather satellite on Mars has been used to warn the rover team of approaching dust storms and has been very valuable for studying the repeated weather patterns on Mars. Also, Jim Bell presented some of the stuff that I have been helping him with, making maps of the surface with MARCI images, and videos of changes such as the dust streaks in Gusev crater.
I think I will stop there for now, and go actually attend the conference some more. I have more to report from yesterday’s afternoon session though, so I’ll post that later.