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Sun-Earth Day Presents: Ancient Observatories, Timeless Knowledge

Technology Through Time: Issue #28, timed

For centuries, scientists have realized that Earth's natural environment is greatly impacted by the abundance of solar energy striking the Earth from a constantly changing sun. In the upper atmosphere, energy from the sun, and from particles in the magnetosphere, combine together to create a complex stew of currents and gas motions.


The TIMED spacecraft is in a circular orbit around Earth, with an altitude of from its 388-mile (625-kilometers ).


The 1,294-pound (587-kilolgram) TIMED spacecraft was launched on December 7, 2001, from Vandenberg Air Force Base in California. The science payload is allowing scientists to look, for the first time in detail, at composition changes in the upper atmosphere; acquire unique measurements of atmospheric cooling as gases radiate energy back into space; measure the primary energy that's deposited into the MLTI region; and measure the speed and direction of winds in this region.


The TIMED mission is studying the influences of the sun and humans on the least explored and understood region of Earth's atmosphere - the Mesosphere and Lower Thermosphere/Ionosphere (MLTI). The MLTI region is a gateway between Earth's environment and space, where the sun's energy is first deposited into Earth's environment. TIMED is focusing on a portion of this atmospheric region located approximately 40-110 miles (60-180 kilometers) above the surface. The TIMED mission is obtaining "global" pictures of this unique region, where energetic solar radiation is absorbed and intense electrical currents flow, which produce beautiful auroras. The spacecraft's instrument suite works with a worldwide network of ground-based observation sites, to make measurements of the upper atmosphere's temperature, pressure, winds, chemical composition, and energy inputs and outputs.