For some reason three of the links from my previous post were excluded.
They provide the best imagery for the Chicxulub meteor impact zone (largely from SRTM and Landsat 7 data).
http://photojournal.jpl.nasa.gov/catalog/PIA03379
http://www.jpl.nasa.gov/news/features.cfm?feature=8
http://neo.jpl.nasa.gov/images/yucatan.html
-Dave