Observations of the solar atmosphere

These observations, taken by NASA’s Solar Terrestrial Relations Observatory, or STEREO on Aug. 5, 2007, helped scientists define the outer limit of the sun’s atmosphere.
Credit: NASA/STEREO

These observations, taken by NASA’s Solar Terrestrial Relations Observatory, or STEREO on Aug. 5, 2007, helped scientists define the outer limit of the sun’s atmosphere.Credit: NASA/STEREOThe sun’s volatile atmosphere is even bigger than expected, a NASA spacecraft revealed through observations of gigantic waves.While the sun itself is 864,938 miles (1.392 million kilometers) wide, NASA’s Solar Terrestrial Relations Observatory, or STEREO, found that the solar atmosphere, known as the corona, stretches 5 million miles (8 million km) above the sun’s surface.”We’ve tracked sound-like waves through the outer corona and used these to map the atmosphere,” Craig DeForest of the Southwest Research Institute in Boulder, Colorado, said in a statement from NASA. “We can’t hear the sounds directly through the vacuum of space, but with careful analysis we can see them rippling through the corona.”via Giant Waves Reveal Surprising True Size of Sun’s Atmosphere.