Staring at the sun

摘要

It's not usually a good idea to stare at the sun - unless you're a $181-million telescope, that is. NASA's Interface Region Imaging Spectrograph (IRIS) will be launched this week to probe an underappreciated aspect of the sun - the region between the star's surface and its sizzling corona, the plasma layer that envelops it. Little is known about what happens here. "IRIS will fill crucial gaps in our understanding of what role the interface region plays in powering the corona," says IRIS mission scientist Jeffrey Newmark.