New analyses of satellite data show that cycles of expansion and contraction are tied to changes in the solar wind
SAN FRANCISCO — Analyses of satellite data reveal that Earth’s atmosphere expands and contracts in response to short-term variations in the solar wind. Understanding this previously unrecognized phenomenon and how it affects objects traveling in low-Earth orbits will enable scientists to better track satellites, and to track the space junk that threatens them.
Besides the more than 800 satellites in low-Earth orbit, more than 17,000 pieces of space junk also circle the planet, reported Jeffrey P. Thayer, an atmospheric scientist at the University of Colorado at Boulder, December 15 at the fall meeting of the American Geophysical Union.
Researchers have long known that variations in the amount of certain wavelengths of ultraviolet light emitted by the sun cause the planet’s atmosphere to swell and shrink. The higher the amount of incoming UV radiation, the warmer the upper atmosphere becomes and the more it expands toward space, Thayer says.