Beautiful Satellite Image Shows United States Caked in Snow & Ice
It can be hard to realize how gorgeous the atmosphere is while you're trying to shovel your 1992 Ford Taurus out of knee-deep slush, but a pair of research satellites 438 miles up in space are indifferent to your suffering and take pictures to remind you of your home planet's beauty.
NASA's Terra and Aqua satellites orbit in such a way that they're able to make near-complete sweeps of the planet each day, taking incredible high-resolution pictures of the Earth's surface and its atmosphere. Each satellite carries a Moderate Resolution Imaging Spectroradiometer (MODIS) that detects different types of energy (e.g., visible light and infrared) to create beautiful images like the one shown above.
This picture was taken early in the day on March 3 by the Aqua satellite while just over half of the continental United States was covered by at least a dusting of snow. It can be hard and sometimes impossible to tell the difference between snow cover and clouds using the visible satellite imagery, but technology aboard the satellites provide the ability to differentiate between the two using "false color" imagery.
Since different types of surface reflect and absorb some wavelengths on the electromagnetic spectrum better than others, the technology in MODIS is able to detect and isolate these differences and paint them with different colors to give you a pretty good idea of what's visible in the picture.
The picture below is a false color copy of the image at the top of this post. The sharp, deep turquoise areas on land are areas covered by snow and sleet, while the paler blue colors indicate cloud cover.
I've outlined the snowy areas in red to help pick them out more clearly:
The University of Wisconsin's Cooperative Institute for Meteorological Satellite Studies (CIMSS) hosts all of the MODIS Today images, along with an archive for both true and false color imagery from the Terra and Aqua satellites dating back to October 2007.
[Images via CIMSS/University of Wisconsin]