Friday, December 23, 2005
Titan With Haze
I thought it'd be nice to leave the site with another pretty face at the top of the posts. This image combines visible light filters with the UV portion of the spectrum to bring out the upper atmospheric haze, that purple halo around the moon.
I didn't mention that other nice image below, of Saturn, shows the gradual shading of the planet's atmosphere from pale yellow-brown to blue. Scientists don't know why the clouds are blue in ring shadow. Astute observers will recall that Neptune is blue, but it is also much colder than Saturn. The blue of Neptune is due to small amounts of methane in the atmosphere. I imagine the rings block enough sunlight to cool the winter hemisphere of Saturn. That would alter weather dynamics just enough for the color to change.
A Saturnian winter lasts more than seven years, by the way. Summer isn't much better, as the planet enjoys balmy highs of -270 degrees. Wind speed is about 1100 mph at the equator, a bit calmer in temperate latitudes.
