Carnival of Space #56
Posted by Emily Lakdawalla
29-05-2008 11:46 CDT
It's Thursday, so it's time for a Space Carnival, hosted this week at the Lifeboat Foundation Blog. Check it out! For some reason it took the page a very long time to load for me -- perhaps they weren't prepared for the traffic.
I'll also point out that the wonderful HiRISE image of Phoenix under its parachute has just been posted at a higher resolution at the HiRISE website. They also posted a little more information about the geometry of the image, which I'll repost here for those of you who slobber over technical details:
This improved image shows some details of the parachute, including the gap between upper and lower sections. At the time of this observation, MRO had an orbital altitude of 310 km, traveling at a ground velocity of 3.4 kilometers/second, and a distance of 760 km to the Phoenix lander.
The image was rotated to a position that seems approximately parallel to the horizon based on the elongation of Heimdall crater, but this is not exact. Thus, although Phoenix appears to hang from the parachute at an angle, as if swaying in the wind, the exact geometry has not yet been determined. The parachute image is very sharp as its apparent motion was straight down the HiRISE TDI (time delay integration) columns. However, the surface of Mars was moving at an angle to the TDI columns, and thus is smeared by a few pixels, although the smear is not apparent at the reduced scale of the image shown here.
The sun is almost directly behind HiRISE, so the parachute should be casting a shadow onto the slope of the crater, but we cannot determine which of many dark spots is the shadow until a detailed geometric analysis has been completed.
HiRISE is currently producing its standard product images for this observation, but it is unlikely that a color version will be available, since the above image is not within the camera's color swath.
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