- Learning About Earth From Space -
While the space program unravels mysteries of the universe, it also reveals valuable insights about Earth. The perspective available from NASA satellites provides a scientific understanding of Earth's interconnected systems and the planet’s response to natural and human-induced changes. The first two decades of the Space Age focused on developing the capabilities of Earth-observing satellites. In the 1980s, NASA began a comprehensive study of our planet as an integrated system. Long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans are improving scientists’ ability to predict climate, weather, and natural hazards. As a research and development organization, NASA has been sharing its new technologies and Earth application programs with other agencies and the private sector.
View of the Earth as seen by the Apollo 17 crew -- astronaut Eugene A. Cernan, commander; astronaut Ronald E. Evans, command module pilot; and scientist-astronaut Harrison H. Schmitt, lunar module pilot -- traveling toward the moon.
Image Credit: NASA
NASA’s Earth resource satellite program began in 1972 with the launch of Landsat 1, the first in a series that continues with Landsat 8, launched in 2013, and will be further enhanced with the anticipated launch of Landsat 9 in 2020. Now conducted jointly by NASA and the U.S. Geological Survey (USGS), Landsat plays a critical role in monitoring, understanding, and managing resources needed for human survival, such as food, water, and forests.
Water: Gravity Recovery and Climate Experiment (GRACE)
GRACE, launched in March 2002, and its very recent replacement, GRACE-FO, each consist of identical twin satellites that measure changes in Earth’s gravity field. These measurements and other data help track the movement of water masses across the planet and mass changes within the Earth itself. The ability to monitor change in ice sheets and glaciers, underground water storage and sea level helps scientists understand important aspects of global change
Image Credit: NASA/JPL-Caltech/University of California, Irvine
This trio of images depicts GRACE satellite observations of declining water storage in California over a 12-year period. Colors progressing from green to orange to red represent greater accumulated water loss.
Are the ice sheets that still blanket the Earth’s poles growing or shrinking? Will global sea level rise or fall? The primary goal of ICESat, launched in 2003, was to quantify ice sheet mass balance and understand how changes in the Earth’s atmosphere and climate affect polar ice masses and global sea level. ICESat-2 will launch in 2018.
Image Credit: NASA
ICESAT will monitor changes in Earth’s glaciers and ice sheets.
Climate Change and Ozone Depletion
Earth As A System: A-Train
Studying how Earth’s systems interact is as important as studying the individual systems. NASA and its international partners operate several Earth-observing satellites, collectively called the A-Train, that closely follow one after another along the same orbital track. The near-simultaneous observations of a wide variety of factors help the scientific community advance our knowledge of Earth-system science and apply this knowledge for the benefit of society.
Instruments for Earth science on the International Space Station
The International Space Station, a unique science laboratory for many different fields of research, has a range of instruments that support Earth science investigations. These tools are generating information that is helping scientists understand and address global environmental concerns. The data and images are particularly useful for helping developing countries facing weather and resource related challenges.
Image Credit: NASA
Dextre, the space station’s robotic arm, carrying the RapidScat instrument assembly. RapidScat, was a radar instrument that measured wind speed and direction over the ocean, and was useful for weather forecasting, hurricane monitoring, and observations of large-scale climate phenomena such as El Niño.