[ Read the Article: STEREO Observations Indicate That Sun's Corona Is Larger Than Expected ]
These highly processed views from NASA’s Solar Terrestrial Relations Observatory show wave motions moving downward through the corona, the sun’s atmosphere, toward the solar surface.
Using STEREO, scientists have found that this atmosphere, called the corona, is even larger than thought, extending out some 5 million miles above the sun’s surface — the equivalent of 12 solar radii. This information has implications for NASA’s upcoming Solar Probe Plus mission, due to launch in 2018 and go closer to the sun than any man-made technology ever has before.
These STEREO observations provide the first direct measurements of the inner boundary of the heliosphere — the giant bubble sparsely filled with solar particles that surrounds the sun and all the planets. Combined with measurements from Voyager 1 of the outer boundary of the heliosphere, we have now defined the extent of this entire local bubble.