Other telescopes, such as the Sunrise 2 balloon that recently completed a five-day flight around the Arctic circle, have looked at the chromosphere but haven’t returned such detailed information. IRIS will not only photograph the sun but will also return spectra-detailed breakdowns of the star’s light that can reveal subtle physical processes at work.
From that vantage point the telescope will observe a small section of the chromosphere, a violently variable region between the corona and the surface. “It may be that by backing out we can get some vital clues to what’s happening.”Ī carrier aircraft will carry IRIS and a Pegasus rocket booster aloft from Vandenberg Air Force Base in California on June 26, and then launch it from there into a polar orbit. “I wonder if maybe we were staring too hard at the corona to understand the corona,” says IRIS scientist Charles Kankelborg, a physicist at Montana State University. The satellite-NASA’s Interface Region Imaging Spectrograph (IRIS), a new ultraviolet space telescope-will examine the chromosphere, a long-ignored layer of plasma beneath the corona, in unprecedented detail. A new satellite will scrutinize the underlying regions of the sun’s atmosphere, giving physicists a chance to dig down like botanists studying a plant’s roots and uncover information that may help them solve the mystery. Although astronomers have developed a few possible explanations in recent years, no one can say precisely how or why the corona gets so hot. The surface, by contrast, is a tepid 6,000 K (around 5,700 degrees Celsius). In the corona, the expansive outer layer of the solar atmosphere that extends millions of kilometers from the sun’s surface, temperatures reach millions of kelvins. Above the surface of the sun, plasma roiling in the star’s atmosphere does something that so far defies explanation, and seems to defy physics: It gets hotter as it moves farther out.