May 30, 2010
The image above shows a huge solar prominence (at bottom) as observed from Marseille, France on the morning of April 13, 2010. According to the Solar and Heliospheric Observatory (SOHO), this was the largest prominence observed in years; stretching an estimated 500,000 miles (804,672 km). Prominences are dramatically erupting, often loop-shaped plasma clouds that hover above the solar disk. They appear to emanate from the Sun's photosphere and protrude into the Sun's extremely hot corona.
Photo details: Lunt 60 mm H alpha; PL1M camera.