Earth Observatory

One of the questions that I'm often asked when running the Google Earth courses is to talk about the sources of information that can be used in Google Earth.
There are lots of these of course.

Google Earth files are usually stored in KML or KMZ format. The two types of document are quite similar - when several files are zipped up they generally have the 'Z' ending.
Opening up large files will slow down Google Earth and may increase the chances of it crashing - it's not 100% stable on some of the machines that I've used it on.

Here's an example of the sort of site that you might come across: the NASA EARTH OBSERVATORY website.
This has a range of KML files which can be viewed in Google Earth.

Google Earth and NASA

Ollie Bray made me aware of this via Boing Boing (getting hard these days to establish who does things first...) which is apparently the completion of something announced a while ago.
NASA are teaming up with Google Earth (and the National Geographic) to release NASA data in areas such as weather forecasting...
Could be useful for Geographers. I'll keep an eye out for more...