UPDATE: On Sept. 30, 2013, the sun released an Earth-directed coronal mass ejection or CME. On Oct. 2, 2013, the CME hit Earth's magnetic field, causing a mild geomagnetic storm, which in turn caused aurora in both the northern and southern hemispheres. The geomagnetic storm caused northern aurora to appear further south than normal in more than a dozen northern-tier US states, including Oregon and New York. In the southern hemisphere, auroras were seen as far north as New Zealand.
Coronal Mass Ejection Speeding Off Sun - Sept. 30, 2013
A cloud of particles known as a coronal mass ejection, or CME, can be seen bursting up and to the right off the sun (obscured by the center disk) in this image. CMEs are a solar phenomenon that can send billions of tons of particles into space.
This image was captured by the European Space Agency and NASA's Solar and Heliospheric Observatory, or SOHO, at 9:54 p.m. EDT on Sept. 29, 2013. Known as a coronagraph, this kind of image blocks the bright light of the sun at the center, thus making the much dimmer atmosphere, the corona, visible.
The CME could be tracked outward from the sun via both SOHO and NASA's Solar Terrestrial Earth Observatory. Scientists track their size and speed – this one is believed to have been moving at around 530 miles per second, a fairly typical speed for CMEs -- in order to better understand a complex space weather system driven by the sun.