The $66 million GOLD is about the size of a mini-fridge and is designed to measure far ultraviolet light. It will examine the Earth from above the Western Hemisphere and generate full-disk maps of atmospheric patterns.
"Just like an infrared camera allows you to see how temperatures change with different colors, GOLD images ultraviolet light to provide a map of the Earth that reveals how temperature and atmospheric composition change by location," Richard Eastes, GOLD principal investigator at the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder, said in a statement.
"For years, we've studied Earth's upper atmosphere in detail from the ground and low-Earth orbit," Eastes added. "By backing out to geostationary [high-Earth orbit], we can put things in a global context. You can see half the Earth from out there."
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From GOLD images taken at 22,000 miles (34,500 kilometers) above Earth, scientists plan to look at parameters such as temperature and the relative amounts of particles such as atomic oxygen and molecular nitrogen. Over time, GOLD will help scientists understand how these gases can change conditions in the atmosphere.
NASA already has a fleet of sun-observing spacecraft, such as the Solar Dynamics Observatory and the Solar and Heliospheric Observatory — and more are on the way. The Parker Solar Probe will launch later this year and observe the sun's upper atmosphere, called the corona. The Ionospheric Connection Explorer will also focus on the Earth's upper atmosphere, but it will fly much closer to Earth — 350 miles — than GOLD.
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