Landsat 7, the satellite behind the best orbital survey of Antarctica ever conducted, has documented other wonders around the world over the past eight years. You might even call it a Hubble Space Telescope for planet Earth, pointing downward at land and sea instead of upward at planets and stars.
In an eerie echo of the past debate over fixing Hubble, policy analysts have worried about losing Landsat 7 before its replacement can be launched in 2011.
More generally, a report prepared last year under the auspices of the National Academy of Sciences said budget cuts were putting America's Earth-observing program at "substantial risk" of collapse.
To address those concerns, a multiagency team was formed by the White House's Office of Science and Technology Policy to focus on the nation's satellite needs, said Ray Byrnes, liaison for satellite missions at the U.S. Geological Survey.
"Fortunately, they were able to release a plan in August of 2007 that called for long-term commitments by the U.S. to fly future satellites like Landsat," Byrnes told reporters today during a briefing at NASA's Goddard Space Flight Center.
If the Earth-observing satellite system ever did start sinking, we'd lose out on more than pretty pictures: Satellites monitor natural phenomena that could have an impact on hundreds of thousands, even millions of people. Today's global web of satellites, for remote imaging as well as communications, is arguably the greatest legacy of the 50 years since Sputnik.
Looking on the bright side, NASA alone has 14 satellites keeping an eye on our planet from above. One of those satellites, the Tropical Rainfall Measuring Mission, marks its 10th birthday today. And despite the worries voiced in the academy report, new eyes in the sky are continually being added - including the commercial WorldView 1 satellite (which just became fully operational this week) and the Italian-built COSMO-SkyMed constellation (with a satellite due for launch next week).
Here's just a taste of the satellite marvels you can find on the Web:
- Earth as Art: Feast your eyes and your ears on our audio slide show of Landsat 7 imagery, which draws heavily on the Landsat program's gallery of artistic observations. (The audio slide show can be a bit balky because of the format changes that have been made since it was created - you might have to back up and try again occasionally.)
- EarthNow! This Java-based viewer gives you a Landsat's-eye view of the terrain passing beneath the satellite's camera, replayed from recent orbital passes.
- Earth Observatory: NASA's premier Web site for Earth imagery blends satellite views with vistas captured from the international space station.
- MODIS: The Moderate Resolution Imaging Spectrometers aboard NASA's Aqua and Terra satellites cover the entire globe every one to two days, and serve as a robotic rapid-response team for natural phenomena. MODIS' gallery highlights the satellites' fresh goodies.
- Envisat: The European Space Agency's "Observing the Earth" portal page provides oodles of cool views, with the Envisat satellite playing the starring role.
- GeoEye: This commercial imagery company serves up a gallery of great shots from the Ikonos and OrbView satellites, and soon the GeoEye 1 spacecraft will be joining the constellation. Don't miss the must-see collection of images from ancient observatories.
- DigitalGlobe: More jaw-dropping views are provided by the commercial QuickBird satellite, and now some brand-new treats have been added: the first images from the recently launched WorldView 1 spacecraft.
- Space Shots: We always include what we think are the best Earth images in our twice-monthly slide show of out-of-this-world pictures. But just in case we're missing some good ones, feel free to point us to more cool views in the comment section below.
