<P> The serial nature of Landsat missions and the fact that is the longest - running satellite program gives it a unique perspective to generate information of earth . Glacier retreat in a big scale can be traced back to previous Landsat missions, and this information can be used to generate climate change knowledge . The Columbia glacier retreat for example, can be observed in false - composite images since Landsat 4 in 1986 . </P> <P> Landsat imagery gives a time - lapse like series of images of development . Human development specifically, can be measured by the size a city grows over time . Further than just population estimates and energy consumption, Landsat imagery gives an insight of the type of urban development, and study aspects of social and political change through visible change . In Beijing for example, a series of ring roads started to develop in 1980s following the economic reform of 1970, and the change in development rate and construction rate was accelerated on these time periods . </P> <P> In 2005, Landsat imagery assisted in the discovery of new species . Conservation scientist Julian Bayliss wanted to find areas that could potentially become conservation forests using Landsat generated satellite images . Bayliss saw a patch in Mozambique that until then had no detailed information . On a reconnaissance trip, on he found great diversity of wildlife as well three new species of butterflies and a new snake species . Following his discovery, he continued to study this forest and was able to map and determine the forest extent . </P> <P> Landsat 8, launched 11 February 2013, is the most recent satellite in the Landsat series . It was launched on an Atlas V 401 from Vandenberg Air Force Base by the Launch Services Program . It will continue to obtain valuable data and imagery to be used in agriculture, education, business, science, and government . The new satellite was assembled in Arizona by Orbital Sciences Corporation . </P>

What is the power source for a landsat satellite