The View From Space From a news story by December 16, 1999
How the land has changed, not only down on the ground but from way out in space. These are the latest images produced by the sharp eyes of a government satellite known as Landsat 7. Darrel Williams works on the NASA Landsat 7 project, "We can see the conditions shortly after the eruption, when just a huge area was totally deforested, literally burned off. Now, 15 years after the fact, we can see light, pinkish view, which says vegetation is growing back, it's starting to reforest." Twenty-seven years of images have tracked the loss of rain forests in South America, as well as the clear-cutting of forests in the U.S. Northwest. Darrel Williams, "Clear cut areas show up quite readily, and it shows we need to look at what's going on in our own back yard, as far as deforestation. Landsat satellites have watched from space as glaciers have shrunk more than four miles over the past decade or so. This is a computer-animated view of Glacier Bay, Alaska, based on new images from Landsat 7. The images of the North Carolina coast after hurricanes Floyd and Irene show the heavy deposits of silt and farm runoff in coastal waters. And these show the increasing summer temperatures around Atlanta, Georgia, a condition scientists say is related to the loss of trees. Darrel Williams says, "It's the most unique record of its type. It's like having a family photo album of anywhere on the globe. And if you don't think you've changed over time, just look at your pictures of the last 20 to 25 years." Now, as Landsat 7 begins its work as the last in a series of earth observers, NASA readies an even more sophisticated satellite, Terra, due to be launched Thursday. Once it's working, Terra is expected to take the vital signs of the globe, including ocean temperatures, energy loss, even the state of the atmosphere, every day.
Additional notes: Landsat 7, soon to be replaced by Terra, is the latest in a group of "earth remote sensing satellites." The latest one was sent into orbit in April 1999, and it is used for civil and commercial purposes besides studies of the environmental changes. Landsat 7 shows deforestation and coastal changes, and it gives info about the effects of strip mining, water resources, urban growth, and agriculture production. For further information about Landsat 7, you may check the following sites:
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