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Our house is ours again
May. 5th, 2005 07:24 pmThe giant fans are gone! I will not miss you, giant fans! And the giant blue industrial dehumidifier, too. I guess the carpet is now completely dry.
May. 5th, 2005
Titan revealed some more
May. 5th, 2005 08:07 pmThe Huygens Descent Imaging and Spectral Radiometer team finally finished the good versions of their image mosaics from the Titan descent.
This was much harder to do than was predicted before the mission. Half the shots were lost because of a mistake in the command script for the Cassini radio relay, but that actually wasn't the biggest difficulty; the probe was spinning faster and in the opposite direction than it was designed to do, and it was also swinging around wildly under the parachute, and there was no hope of its Sun sensor getting a lock even if the atmosphere had been transparent enough to manage it (which is unlikely). So these pictures had no reliable probe orientation data associated with them, and they had to be pieced together completely by eyeball, which is made harder by the fact that they're lossily compressed to hell and gone to fit into the meager bandwidth available to the probe.
Still, the assembled mosaics provide a lot of context that makes shots that looked like garbage in raw form suddenly stand out as pictures of objects. They make it even clearer that the probe landed in the dark "sea" which is actually a sort of muddy lowland, and it's not even completely flat; the landing site was close to a peculiar ridge about a kilometer long with a series of slots cut into it. I guess the camera was looking in the opposite direction after the probe actually landed.
Also, the Planetary Society's Titan image page now has the complete radar swaths for the two passes of Titan that have obtained them. They're worth a look. (The links to them from the main Saturn page are broken; this is a frequent problem with the Planetary Society site—they don't check their links very assiduously.)
Most of the flybys to date have not included radar; there's the tradeoff that pointing the big dish at Titan precludes using most of the other instruments at the same time. Since Cassini's synthetic aperture radar turns out to work better than expected, and is clearly the best way of seeing details of the surface from space, I hope that the radar passes will be more frequent in future Titan encounters.
This was much harder to do than was predicted before the mission. Half the shots were lost because of a mistake in the command script for the Cassini radio relay, but that actually wasn't the biggest difficulty; the probe was spinning faster and in the opposite direction than it was designed to do, and it was also swinging around wildly under the parachute, and there was no hope of its Sun sensor getting a lock even if the atmosphere had been transparent enough to manage it (which is unlikely). So these pictures had no reliable probe orientation data associated with them, and they had to be pieced together completely by eyeball, which is made harder by the fact that they're lossily compressed to hell and gone to fit into the meager bandwidth available to the probe.
Still, the assembled mosaics provide a lot of context that makes shots that looked like garbage in raw form suddenly stand out as pictures of objects. They make it even clearer that the probe landed in the dark "sea" which is actually a sort of muddy lowland, and it's not even completely flat; the landing site was close to a peculiar ridge about a kilometer long with a series of slots cut into it. I guess the camera was looking in the opposite direction after the probe actually landed.
Also, the Planetary Society's Titan image page now has the complete radar swaths for the two passes of Titan that have obtained them. They're worth a look. (The links to them from the main Saturn page are broken; this is a frequent problem with the Planetary Society site—they don't check their links very assiduously.)
Most of the flybys to date have not included radar; there's the tradeoff that pointing the big dish at Titan precludes using most of the other instruments at the same time. Since Cassini's synthetic aperture radar turns out to work better than expected, and is clearly the best way of seeing details of the surface from space, I hope that the radar passes will be more frequent in future Titan encounters.
Story arcs
May. 5th, 2005 11:24 pmMany people have wondered whether the backstory gradually being revealed in Russell T. Davies' Doctor Who revival owes anything to the tie-in novels about the Paul McGann Doctor (to which it bears only a vague resemblance). But...
( minor new-series spoilers by implication... )
( minor new-series spoilers by implication... )