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Satellites shed light on Earth Day


NASA's "Eyes of the Earth" Web-based viewer shows you the orbital locations of the space agency's Earth-observing satellites in real time.

The planet celebrates its 42nd annual Earth Day on Friday, and a lot of the coolest gifts to mark the occasion are coming from places that are out of this world: the dozens of satellites that are keeping watch from orbit.

Here are just a few of the goodies that NASA and other satellite operators are providing to mark the occasion:

Chat with a satellite scientist: Today at 1 p.m. ET, Annmarie Elderling is the guest star for an online video chat that's being aired on UStream. Elderling is a research scientist at NASA's Jet Propulsion Laboratory who specializes in the study of clouds, aerosols and trace gases in Earth's atmosphere. She's the deputy project scientist for Orbiting Carbon Observatory-2, a satellite mission now in development that will measure atmospheric carbon dioxide. (OCO-1 was lost in a launch mishap two years ago.)

Chat with an Arctic explorer: On Earth Day, NASA presents an online chat with Lora Koenig, deputy project scientist for Operation IceBridge. This is an airborne science mission that is monitoring Greenland's ice sheet with a variety of instruments. She'll be logging on from Kangerslussuag, Greenland, at 3 p.m. ET on Friday. Tom Wagner, NASA's cryosphere program manager, will participate in the chat as well from NASA Headquarters in Washington.

Enter a video contest: NASA is asking video mavens to put together short YouTube videos that celebrate Earth Day and the exploration of our home planet. The deadline for submissions is May 27, and the entry that's judged the best by NASA scientists and communicators will be featured on the space agency's home page. Check out the details on the "Home Frontier" contest Web page.

Learn about Earth's endangered ice: DigitalGlobe, which operates a constellation of Earth-observing satellites, is featuring its collaboration with the Extreme Ice Survey to study what's happening to the world's glaciers. Researchers suggest that glaciers serve as something of a "canary in the coal mine" for climate trends, and the bird isn't looking all that great these days. DigitalGlobe's satellite imagery documents glacial shrinkage as seen from space, while the Extreme Ice Survey has deployed dozens of time-lapse cameras to monitor glaciers on the ground. 

Track Earth-observing satellites ... and more: NASA's "Eyes of the Earth" Web page offers a smorgasbord of interactive graphics, including a 3-D satellite viewer that lets you track the space agency's Earth-observing satellites in real time (or speed up the timeline as much as you want). Check out the "My Big Fat Planet" blog, click through dramatic then-and-now imagery from Earth's environmental frontiers, and focus in on NASA's top five Earth images, based on Facebook and Twitter popularity.

Explore the Earth Observatory: NASA's Earth Observatory is the go-to Web site for daily Earth imagery from satellites as well as from the International Space Station. "World of Change" is a feature that documents how natural and human-caused phenomena have transformed our planet over the years. 

More out-of-this-world perspectives:

Check back later for additional pointers to out-of-this-world Earth Day resources. 

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