NASA solar observatory probes mysteries of sun's surface

A solar observatory has shown the region between the surface of the sun and its atmosphere to be a more violent place than previously understood, NASA says. The evidence is in unprecedented images taken by NASA's newest solar observatory, the Interface Region Imaging Spectrograph, or IRIS, launched in June, the space agency reported this week. IRIS' mission is to study what's known as the interface region -- a layer between the sun's surface and corona that previously was not well-observed, scientists said. Over its first six months, IRIS has produced images of the interface region showing it to be even more turbulent and complex than expected, they said. "The quality of images and spectra we are receiving from IRIS is amazing," said Alan Title, IRIS principal investigator at Lockheed Martin in Palo Alto, Calif. IRIS is making it possible to study the explosive phenomena in the interface region in sufficient detail to determine their role in heating the outer solar atmosphere, the researchers said. IRIS looks at the sun in layers, capturing light emitted by atoms of different temperatures at different heights above the sun's surface extending well out into the solar atmosphere, the corona. "We are seeing rich and unprecedented images of violent events in which gases are accelerated to very high velocities while being rapidly heated to hundreds of thousands of degrees," Bart De Pontieu, the IRIS science lead at Lockheed Martin, said. "These types of observations present significant challenges to current theoretical models."