Giant Wall of GasA giant wall of heated gas rises from the sun's surface in a false-color photograph taken by solar observer Stephen Ramsden last Friday. Known as prominences, these solar features are anchored to the sun's surface but can extend many tens of thousands of miles into space. "If you see [videos] of these things, they're constantly in motion," said Joseph Gurman, a solar astronomer at NASA's Goddard Space Flight Center in Maryland."The material doesn't actually stay up there for very long. It's constantly being replenished."While solar prominences are fairly common, the ones captured in recent photos by solar observers around the world are unusually tall and look to be on the verge of being ejected into space, Gurman said.Gurman estimated that this particular prominence is about 62,000 miles (100,000 kilometers)—or roughly the width of eight Earths—tall.(Related: "Sun Erupts: Epic Blast Seen by NASA Solar Observatory.")The dark section at the bottom of the photograph is the surface of the sun, which photographer Ramsden artificially blackened so it wouldn't overwhelm the other solar features.—Ker Than

Image courtesy Stephen Ramsden