It Came from the Sun

Explanation: What's that coming over the edge of the Sun? What might appear at first glance to be some sort of Sun monster is actually a solar prominence . The above prominence , captured by the Sun-orbiting SOHO satellite earlier this year during an early stage of its eruption , rapidly became one of the largest ever on record. Even as pictured, the prominence is huge -- the Earth would easily fit inside. A solar prominence is a thin cloud of solar gas held just above the surface by the Sun's magnetic field . A quiescent prominence typically lasts about a month, while an eruptive prominence like the one developing above may erupt within hours into a Coronal Mass Ejection (CME), expelling hot gas into the Solar System . Although very hot, prominences typically appear dark when viewed against the Sun , since they are slightly cooler than the surface. As our Sun evolves toward Solar maximum over the next three years, more large eruptive prominence s are expected.