NASA takes periodic sat photos of the earth and every so often they get them all together and release them. Blue Marble Next Generation is the latest collection of high resolution images from 2004, one for each month with cloud cover removed, and was released yesterday. It's pretty neat to see the seasons changing all around the earth. Even more dramatic when viewed using NASA's WorldWind app with the Blue Marble add on that dynamically grabs/adds data. (Google Earth doesn't have this dataset (yet?)). If you don't have either, use the web based version done up by the NASA scientist (Reto Stöckli) who headed up the project (or, this one, if you don't mind installing ActiveX thingies).
Satellite remote sensors provide the science community with high quality datasets to better understand and monitor Earth’s environment and climate system. When used in education, these datasets allow visual exploration of the planet at moderately high spatial and temporal resolutions. However, native data file formats and file sizes are not well suited for public distribution. To help circumvent these issues, the Blue Marble Next Generation (BMNG) is a new series of 12 monthly cloud-free, global-scale images. We created the BMNG using NASA Terra MODerate resolution Imaging Spectroradiometer (MODIS) science data collected in 2004. We temporally adjusted the data using a discrete Fourier technique. This correction method removed cloud disturbances, but snow reflectance remains a significant challenge. The BMNG visualizes seasonal changes of the land surface (spring greening, snowmelt, drought, etc.) as true-color images and Normalized Difference Vegetation Index (NDVI) maps in monthly steps at 500-m spatial resolution. The images are available at no cost from NASA.
- R. St¨o;ckli, E. Vermote, N. Saleous, R. Simmon and D. Herring (2005). The Blue Marble Next Generation - A true color earth dataset including seasonal dynamics from MODIS. Published by the NASA Earth Observatory. Corresponding author: rstockli@climate.gsfc.nasa.gov
[edit: 10/15/2005 1:28AM]
Looks like the WorldWindCentral.com guys put up a tileserver / kml generator for Google Earth. Check out the post here.