New Views of Diverse Worlds
Mercury Autumn 2011 Table of Contents
by David T. Blewett
|
| False-color image of Mercury. Courtesy NASA / Johns Hopkins University Applied Physics Laboratory. |
A lot of strange sights have been seen on Mercury, things that the MESSENGER team is still trying to understand. For instance, the images reveal certain craters that have dark rims; several are found within the Caloris basin. This rather surprising. The dark rim indicates that the impact dug up dark material from beneath the surrounding smooth plains, which have a higher albedo.
Another class of crater on Mercury has highly unusual bright stuff on their floors. Mariner 10 spotted a number of them, though at fairly poor spatial resolution, and few scientists at the time really thought much about the bright material. But now we've seen many more with MESSENGER — I'll have more to say about them later on, but they're turning out to be amazing.
If you enjoyed this excerpt from a feature article and would like to receive our quarterly Mercury magazine, we invite you to join the ASP and receive 4 issues a year.