For commercial imaging satellites, every day is Earth Day: In honor of today's eco-conscious holiday, GeoEye is releasing four recent snapshots of the planet, taken by the company's GeoEye-1 satellite as it orbited 423 miles (681 kilometers) above.
Earth Day isn't just a day for pretty pictures. It's also an occasion to reflect on the state of the planet. This picture of broken-up icefields near Adelaide Island, off the coast of the Antarctic Peninsula, is a reminder that our planet's changing climate is a continuing cause of concern. The Antarctic Peninsula is considered one of the world's fastest-warming "hotspots," as documented by imagery from Europe's Envisat satellite.
"Ice shelves are sensitive to atmospheric warming and to changes in ocean currents and temperatures," Helmut Rott, a professor from the University of Innsbruck in Austria, explained in a statement issued earlier this month. "The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5 degrees Celsius [4.5 degrees Fahrenheit] over the last 50 years —a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves."
Antarctica's situation serves as a "canary in the coal mine" for the effects of global climate change and the greenhouse-gas effect, to which industrial activity is an increasing contributor. But this isn't just an issue for penguins around the South Pole, or polar bears around the North Pole. Opinion surveys indicate that the public is increasingly seeing a connection between global changes in climate and the way weather works in their own region.
For more about the Antarctic Peninsula in particular, check out this report about the effect of climate change on penguin breeding patterns, this one about concerns for seal pups, this one about the encroachment of invasive species, and this video from 2007 about the continent's shrinking "cathedral of ice." Msnbc.com's Environment section has complete coverage of today's Earth Day goings-on.
Where in the Cosmos
GeoEye's picture of the Antarctic Peninsula was the subject of our latest "Where in the Cosmos" picture puzzle, posted to the Cosmic Log Facebook page. Stacy Thompson Layman was the Cosmic Log correspondent who first came up with the location shown in the picture (after a few hints), and to reward her late-night effort, I'm sending her a pair of 3-D glasses and a copy of "The World in 2050: Four Forces Shaping Civilization's Northern Future," which makes for relevant reading on Earth Day. To get in on future "Where in the Cosmos" puzzle contests, be sure to click the "like" button for Cosmic Log. Here are the three other GeoEye-1 snapshots:
More views of Earth from space:
- Slideshow: Earth as Art 2010
- See the world from the space station
- Slideshow: How astronauts saw Earth
- Holiday calendar 2011: Earth from space
Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.