[X] My Assistant

[volcanopele]

Titan's Enigmatic Infrared-Bright Spot Is Surface Make-Up
By Lori Stiles
October 06, 2005

http://uanews.org/cgi-bin/WebObjects/UANew...ArticleID=11813

A 300-mile-wide patch that outshines everything else on Titan at long infrared wavelengths appears not to be a mountain, a cloud or a geologically active hot spot, University of Arizona scientists and Cassini team members say.

"We must be looking at a difference in surface composition," said Jason W. Barnes, a postdoctoral researcher at UA's Lunar and Planetary Lab. "That's exciting because this is the first evidence that says not all of the bright areas on Titan are the same. Now we have to figure out what those differences are, what might have caused them."

----

The paper, "A 5-Micron-Bright Spot on Titan: Evidence for Surface Diversity" is now published in Science:

http://www.sciencemag.org/cgi/content/abstract/310/5745/92

This article is about Hotei Arcus, an arc-shaped feature in southeastern Xanadu. This feature appears brighter than its surroundings in almost all wavelengths that see the surface, including ISS' 938-nm, but the feature appears exceptionally bright at 5-microns. Another feature with similar characteristics is Tui Regio. I've attached a few views from VIMS from Ta. A close-up of Tui Regio from ISS can be found here

[Olvegg]

And what could be these white dots at 4.989 microns? Are they real or just artifacts? It seems like one of them appears at wavelength 2.799 (upper right), but not exactly in the same place.

[volcanopele]

And what could be these white dots at 4.989 microns? Are they real or just artifacts? It seems like one of them appears at wavelength 2.799 (upper right), but not exactly in the same place.

Those are just noise hits. The signal/noise ratio at 5 microns is pretty low, so bright pixels like those are not uncommon.