Astronaut Photography - Observing Earth's Systems from Space
by Rebecca Dodge in collaboration with NASA scientists
Crew Earth Observations
Shuttle astronauts have made numerous observations of the Earth's surface and atmosphere, on a "target of opportunity" basis. The unique information gained from these real-time observations culminated in a specific program for astronaut photography from the ISS, called Crew Earth Observations3. This earth observation program, designated as a special "payload" on the ISS, focuses on changes and interconnections among the Earth's surface, atmosphere, biosphere, and oceans, and on human relationships and contributions to such change. Dynamically-changing sites around the world have been selected in cooperation with an international group of interdisciplinary scientists and researchers. NASA is committed to continuing its earth observation mission within several broad science themes that span the entire Earth System, building on a resource of literally hundreds of thousands of astronaut photographs spanning over 35 years of space-based earth observations. Initial themes include:
Dynamic Events (e.g. Hurricanes, dust storms, plankton blooms, volcanic eruptions)
Photographs can encompass vast areas of the Earth with oblique viewing angles, as seen to the left4. This broadest view possible shows the Pacific Ocean, with the coral atolls of Tabitueua and Onotoa in the foreground. Coral reefs are sensitive environmental indicators of change in the Biosphere, the Atmosphere, and the Hydrosphere. Coral reefs are just one of the targets of the CEO program.
4. (http://earthobservatory.nasa.gov/Study/EdLu/ Watching the World Go By ISS007-E-7304 June 13, 2003)
Astronauts can also focus on smaller regional oblique views such as the photograph of western U.S. to the right4. Regional overviews such as this demonstrate connections as well as differences among land cover, climate, and tectonic history over broad physiographic regions. Understanding tectonic processes and history, especially in remote regions of the Earth, will be aided by CEO-targeted photographs designed to help scientists understand Lithosphere processes such as earthquakes and volcanic eruptions.
With longer lenses astronauts can also obtain better resolution photographs, such as the nadir sequence of San Francisco shown to the left. In the top photograph the San Francisco-Oakland metroplex surrounds San Francisco Bay4. Sediment-laden water flows into the Bay's southern end and is carried northward through the Bay in discrete currents that join sediment-laden water brought into the Bay by the Sacramento River. Turbid water flows out of the Bay into the Pacific Ocean, bringing important nutrients into the marine ecosystem. Land cover change associated with development and agriculture can dramatically increase sediment input into the marine Hydrosphere. Plankton blooms associated with such nutrient input are another target for the CEO research project.
The photograph to the right4, taken with a high-resolution lens, zooms in on salt evaporation ponds bordering the southeastern end of the Bay. Variable algal concentrations create vivid colors in the evaporation ponds, which replaced coastal wetlands that provided important habitats for terrestrial and aquatic species. These salt ponds are being restored to wetlands status, reestablishing an important Biosphere refuge for nesting migratory birds5.
5. (Salt Ponds, South San Francisco Bay http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=10263)
In addition to the dynamic events occurring over the oceans and on the land surface, dynamic events in the Atmosphere itself are the target of astronaut photography. Even during the construction phase astronauts where actively acquiring photographs6.
6. (First Image of Earth from the International Space Station http://eol.jsc.nasa.gov/EarthObservatory/First_Image_of_Earth_from_the_International_Space_Station.htm)
Crew Earth Observations >>
Dynamic Events >>
Coral Reefs >>
El Nino >>
Volcanic Eruptions >>
Urban Areas >>