Eye in the Sky

In 1972 NASA and the USGS partnered to develop and manage a series of Earth-observing satellite missions. The series of satellites, known as Landsat, have been used by governments, scientists and educators to monitor changes of the Earth's land surface. Landsat satellites collect information about Earth from space using remote sensing and provide a means for measuring such changes as the amount of healthy vegetation, extent of damage and rate of regeneration following a forest fire, and various other applications of interest. These tools enable people to study many aspects of our planet and to evaluate the dynamic changes caused by both natural processes and human practices.

Since the launch of Landsat 1 in 1972, these satellites have continuously monitored the Earth. The USGS currently operates Landsat 5 and Landsat 7. These satellites contribute over 400 images per day to the USGS Center for Earth Resources Observation and Science (EROS) data archive. Today, Landsat technology has expanded by the arrival of EarthNow!, an online outreach tool developed to show near-real time satellite imagery from data received from the Landsat 5 and Landsat 7 satellites as they pass over the United States. When a Landsat satellite passes within range of the ground station at the EROS center, image data are downlinked and displayed on the website. When Landsat 5 and 7 are not in range, the most recent pass is displayed.

EarthNow! is a great resource for scientist, educators and the general public interested in the dynamic surface changes of our Earth. Here are a few examples of how researchers at NOROCK have used Landsat to map landcover and landscape change:

• To study burned areas in and around our national forest and to monitor fire effects on Federal lands. l More Info l
• To map the distribution of whitebark pine, a major food source for bears, in the Greater Yellowstone Ecosystem. l More Info l
• To study of wetlands and groundwater recharge at Red Rock Lakes National Wildlife Refuge. l More Info l

For more information about EarthNow! visit the EarthNow website at: http://earthnow.usgs.gov or http://landsat.usgs.gov/