The Sun has unleashed its strongest flare in four years, observers say.
Could there be a massive planet well beyond the orbit of Pluto? Unfortunately, this "extraordinary" claim is based on rather "ordinary" evidence.
First ever STEREO images of the entire Sun
As the team of scientists behind NASA’s MESSENGER spacecraft eagerly awaits the craft’s entry into Mercury’s orbit on 17 March, we could soon get answers to questions about the origin, composition, interior structure and geological history of this mysterious planet.
On August 1, 2010, an entire hemisphere of the sun erupted. Filaments of magnetism snapped and exploded, shock waves raced across the stellar surface, billion-ton clouds of hot gas billowed into space. Astronomers knew they had witnessed something big. It was so big, it may have shattered old ideas about solar activity.
