WASHINGTON, D.C., August 1 -- NASA and the US Geological Survey (USGS) have assembled an exhibit, "Landsat: Earth as Art," to celebrate the 30th anniversary of the first Landsat launch. The exhibit's 41 images, created by the USGS using Landsat 7 data, introduce the general public to the Landsat Program, which is administered jointly by USGS and NASA. The exhibit opened July 23 at the Library of Congress in Washington. The first Landsat -- originally called ERTS, for Earth Resources Technology Satellite -- was developed and launched by NASA in 1972. Landsat 5 is still transmitting images. Landsat satellites monitor natural processes and human land use such as vegetation growth, deforestation, agriculture, coastal and river erosion, snow accumulation and fresh-water reservoir replenishment and urbanization. The USGS uses Landsat data to spot the amount and condition of dry biomass on the ground, which are potential sources for feeding wildfires. Farmers and land managers use Landsat data to help increase crop yields and cut costs while reducing environmental pollution.