These wavelengths of light have a significant impact on the thermosphere, where air molecules absorb their energy and the reradiate it in the form of infrared energy.

MSN: Earth's upper atmosphere cooling dramatically

Earth's thermosphere is one of the least explored parts of the atmosphere, but it is important because "the thermosphere is where the sun first interacts with our atmosphere, " said James Russell III of Hampton University in Hampton, Va.

MSN: Earth's upper atmosphere cooling dramatically

The data, from NASA's TIMED mission, show that Earth's thermosphere (the layer above 62 miles or 100 km above the Earth's surface) "responds quite dramatically to the effects of the 11-year solar cycle, " Stan Solomon of the National Center for Atmospheric Research in Boulder, Colo.

MSN: Earth's upper atmosphere cooling dramatically