Monday, June 2, 2008

Martian Update

I made quite a fuss over the Phoenix lander a bit more than a week ago (See here and here), but I haven't updated at all. Things went good. Really, really good. It was a picture perfect descent:
(note: most of these pictures can be seen larger by clicking on them. Some have larger versions still on the pages linked)

This picture (from here) makes it look as if the lander is in or headed toward a crater; actually, as was intended, it landed well outside. From the perspective of the orbiting satellite that shot the image (I believe it was HiRise), Phoenix looks like it's in the crater but is well in front of it. This is one of those pictures that just dropped my jaw- it's the first time we've captured the sight of a lander from another planet. Below is an enlargement & enhancement of the inset from the picture above (from here)
This is the one that showed up on most of the news sources, though I think the first is more dramatic and stunning. The nice thing about this one is that you can clearly see the parachute, the tether and the lander below.

It was a picture-perfect landing. It was reported pretty quickly that the lander was almost perfectly level: only a half degree off horizontal. I presume the next picture was shot by the same satellite that shot the first two, but on a later pass (from here)

There was some glitch in the radio link a day or two after the landing, but they got that fixed quickly, and it ended up causing only a minor delay to the program. The operators got the arm unstowed from the protective film used to cover the arm during sterilization and transit. This is hoped to protect the planetary surface from contamination (or infection, really) by earthly microorganisms. A day or two ago, the arm performed a "practice scoop" to test its ability to scoop up soil samples and transfer them to a combined heater/gas spectrometer. By slowly heating up the sample, different gases will be driven off through time. The gas spec can for the most part identify what those gases are, giving scientists a profile of the material's composition.

Now, the Grand Finale: The whole purpose of landing near a pole is to examine ice that we know is there. Based on past radar data, it was believed that this area was an ice sheet covered with a thin (2-6 inch) mantle of soil. A couple of days ago, there was an intriguing glint of white picked up on an image of the ground near the base of the lander. They maneuvered the camera around to look under the lander and saw: (from here)

The landing rockets excavated about two to six inches of soil, and look at all that white stuff! This isn't a huge surprise- as I said, it's basically what they were expecting. But to actually see it? WOW! As of this writing, scientists are hedging their bets and saying it might be salt, but their working hypothesis is that it is ice. I expect that will be confirmed before too long.

There's an article on ScienceDaily that provides a little more info on this last pic.

So all in all, it's been a picture perfect mission so far.

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