Magnetic Vision?

garden warbler by Tommy Holden. British Trust for Ornithology websiteThis is simply fascinating. I heard about it on NPR. While it is well known that birds are sensitive to the earth’s magnetic field, and use it to navigate, apparently it’s only been recently shown that this sensitivity is connected directly to the visual system (at least in some birds). The idea seems to be that the bird has evolved a mechanism for essentially seeing the magnetic field, presumably in the sense that magnetic information is encoded in the visual field and mapped to the brain along with the usual visual data. (Image: A garden warbler, photographed by Tommy Holden. I found it on the British Trust for Ornithology website, here.)

Have a listen to the NPR interview with Henrik Mouritsen (professor of neurosensory science at the University of Oldenberg in Germany – and among other things also a keen wildlife photographer, I learned from his website), and learn more about his […] Click to continue reading this post

Dawn at Dawn

Well, it is time for Round Two!

dawn spacecraft getting readyRecall that (as mentioned in my post with the doom-laden title) the Dawn mission was postponed by several months due to unfavourable launch conditions. Recall also that the celestial window for launching Dawn will not come again for another seventeen years, if it does not launch over the next couple of weeks or so! This is a bit scary therefore.

So the two week launch window is open, and Dawn is on the pad and ready to try to fly tomorrow, at around….. dawn. They’ve been preparing Dawn for this for a while now (you can see in the picture on the right some of the preparations – encasing it in the protective dressing for the rocket launch… I got this picture from this link and you can see more there), and from the press release of yesterday confirming that the mission is a “go”:

dawn spacecraft rendition“If you live in the Bahamas this is one time you can tell your neighbor, with a straight face, that Dawn will rise in the west,” said Dawn Project Manager Keyur Patel of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Weather permitting, we are go for launch Thursday morning – a little after dawn.”

Dawn’s Sept. 27 launch window is 7:20 to 7:49 a.m. Eastern Daylight Time (4:20 to 4:49 a.m. Pacific Daylight Time). At the moment of liftoff, the Delta II’s first-stage main engine along with six of its nine solid-fuel boosters will ….

They also talk a bit about the science (also see later, below this): […]
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