Planetary Paparazzi: 10 Vital Views of Earth [Slide Show]
Icelandic eruptions, oil spills, deadly heat: NASA's Terra satellite has captured spectacular views of such dramatic events, documenting our planet's ever-changing visage since the satellite's five sensors saw "first light" 10 years ago
SMALLER BY THE DECADE Once the fourth-largest lake in the world, the Aral Sea is now all but extinct. Terra's MODIS sensor has documented the sea's shrinkage since 2000, when the lake was already a fraction of its 1960 extent because of a massive irrigation project that has diverted water away from the sea for decades [
left]. By summer 2009, dust covered much of the former seabed [ right].
DEADLY HEAT WAVE During the height of a deadly heat wave on August 4, 2003, Europe emitted as much heat as the Sahara Desert in northern Africa did. This image is from Terra's Clouds and the Earth's Radiant Energy System (CERES) sensor, which takes stock of the quantity of solar energy the planet's atmosphere and surface absorbs as well as how much infrared and heat energy it radiates back into space. This ever-changing balance is what ultimately determines Earth's climate.
STREAMING POLLUTION Monitoring concentrations of atmospheric carbon monoxide—in this case, over eastern China and the Pacific Ocean—allows scientists to observe both the sources and transport of pollution on a global scale. This composite image of data that Terra's Measurements of Pollution in the Troposphere (MOPITT) sensor collected during February 2006 is representative of the considerable annual flow of pollution out of the region. Researchers have used Terra data to track numerous Asian pollution plumes all the way to the U.S., indicating that international cooperation may be necessary to meet national air-quality goals.
NASA/NCAR/University of Toronto
ERUPTION IN ICELAND Terra’s MODIS sensor also captured this image of Iceland’s Eyjafjallajökull volcano as it continued to emit a dense plume of ash and steam on May 7, 2010. And just as the MISR team was able to track the smoke plume from the Station Fire, it used a series of images from multiple angles to measure the height of the volcano’s ash cloud and the concentration of particles in the plume.
Erratum (6/2/2010): The caption was changed to indicate that the image was taken by the MODIS instrument, not by MISR. NASA Earth Observatory Advertisement
WILEY WILDFIRE California’s Station Fire, the largest in the recorded history of Los Angeles County, spread aggressively during the morning hours of August 30, 2009, the day Terra’s MODIS instrument acquired this image. Another Terra sensor, the Multiangle Imaging SpectroRadiometer (MISR), tracked the fire’s smoke blowing over Nevada, Utah and Colorado by collecting a series of images at multiple angles and constructing three-dimensional images of the plume. Terra’s Measurements of Pollution in the Troposphere (MOPITT) tracked the fire’s carbon monoxide emissions all the way to Louisiana.
Erratum (6/2/2010): The caption was changed to indicate that the image was taken by the MODIS instrument, not by MISR. NASA Earth Observatory
GULF OF MEXICO OIL SLICK Terra's MODIS sensor can also capture photolike images, such as this view of an oil slick lurking not far from the Mississippi Delta on the morning of May 10, 2010.
NASA Earth Observatory
STUNTED STORAGE How much carbon land plants store during photosynthesis, a measure known as net primary productivity, changes from season to season. That explains why the Northern Hemisphere was so much "greener" in August 2009 [
top] than in March 2010 [ bottom]. A recent analysis of these monthly compilations, based on measurements from Terra's Moderate-Resolution Imaging Spectroradiometer (MODIS), revealed that changes are happening year to year as well. Annual global uptake of carbon has been declining since 2000, probably as warming-related droughts stunt the growth of crops and vegetation in the tropics and Southern Hemisphere. NASA
SICKENING BLOOMS Terra's ASTER sensor captured this view of filaments of blue-green algae swirling across Guatemala's Lake Atitlán on November 22, 2009. Such algal blooms are not only harmful to people and animals but can also trigger dead zones in the lake—areas in the water so devoid of oxygen that they cannot support aerobic life. To aid mitigation efforts of this and other types of natural hazards, ASTER operators can point the sensor at requested targets and acquire about 500 high-resolution images a day.
NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team Advertisement
ELEVATING LANDSCAPES This view of the Los Angeles Basin, looking northwest toward the San Gabriel Mountains, is a simulated natural-color image draped over digital topography, both from Terra's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The ASTER team released this image in June 2009 to promote its new global digital elevation model, which remains the most complete and consistent data set of its kind.
NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team
THE BLUE MARBLE This iconic image leads the legacy of NASA's Terra satellite, a flagship of the agency's Earth-observing fleet. Now in its 10th year of monitoring the land, oceans, sea ice and clouds, Terra tracks environmental change like a doctor monitors a patient's vital signs. Reminiscent of photographs taken by astronauts on the moon, this digital image from 2002 is the stitching together of months of Terra observations of into a seamless mosaic, with resolution down to one square kilometer.