Astronomy Picture of the Day . An X Class Flare Region on the Sun . ... 6.11.2007 . ... Credit Copyright: TRACE Project , NASA Explanation: Why does the Sun flare? Unpredictably, our Sun unleashes tremendous flares expelling hot gas into the Solar System that can affect satellites, astronauts, and power grids on Earth. This close up of an active region on the Sun that produced a powerful X-class flare was captured by the orbiting TRACE satellite . ... Publications with keywords: Sun . ...