Tuesday, May 27, 2008

Phoenix Photos...

Here's a fine mosaic put together by the Phoenix team from many individual images. Eventually they'll have the entire site mapped with full-color, stereographic photos. The technology used for surface imagery keeps getting better and better – this mosaic is, for all practical purposes, competely free of seams and other artifacts that usually appear. They've got the techniques and technology pretty much nailed...

This photo shows the scene from one side of the lander all the way to the horizon. Notable things immediately visible include the hummock-and-trough terrain extending right up to the lander (this is good, because the scientists want to dig both in a hummock and in a trough), the low hills on the horizon (very useful for figuring out exactly where the lander is), the wide expanse of similar terrain (good because it tells us that the lander didn't happen to squat on an anomalous piece of Mars), and, just for fun, a white artifact in the upper left corner of the scene.

That artifact appears at right, blown up just as big as I can make it. It's very tempting to conclude that it's something man-made, as it doesn't look like anything else in the surrounds.

There are several candidates for such a man-made object: the “backshell”, the heat shield, and the parachute.

The backshell is the shroud that protected Phoenix as it cruised from Earth to Mars; it is most likely still attached to the parachute. As Phoenix descended through the Martian atmosphere, first it decelerated through atmospheric drag, protected by the heat shield. Once it had slowed down sufficiently, the parachute deployed to slow it still further. While under canopy, the heat shield was discarded. At about 1,000 meters of altitude, the lander separated from the backshell (which was still attached to the canopy), dropping away, then using rocket motors to descend slowly to the surface.

Given this sequence, the heat shield is most likely several kilometers (or more) away from the lander, but the backshell and parachute could be within a few hundred meters – just where this artifact appears to be.

Or it could be a Martian, playing a joke on us by rolling up a nice big snowball.

My bet is on the backshell/parachute...

No comments:

Post a Comment