prominence: A prominence is a gigantic eruption of heated gas from the Sun's chromosphere into the corona. Sometimes a prominence will fall back toward the photosphere in an immense arch. Sometimes it will hang in the corona for days. Eventually the gas cools and drops back down to the Sun's surface, or it drifts off into space. Prominences may shoot out of the Sun at 1 million miles per hour, and they may reach 120,000 miles (193,200 km) into the corona. Prominences are a type of solar activity associated with sunspots and magnetic activity.
