Solar event gives prospect of spectacular auroras this weekend

Posted Mar 16, 2013 by Robert Myles
Early yesterday morning NASA released details of an observed solar phenomenon, an Earth-directed coronal mass ejection with the potential to disrupt satellites and communications over the next one to three days.
A coronal mass ejection hit Earth s magnetic field on Oct. 8  2012 sparking a dramatic display of No...
A coronal mass ejection hit Earth's magnetic field on Oct. 8, 2012 sparking a dramatic display of Northern Lights which subsided 3 days later. The Aurora appears to be casting rays of green sunlight through the clouds. Hugo Løhre photographed the auroras over Lekangsund, Norway, on Oct. 10, 2012.
NASA Images - courtesy of Hugo Løhre
Based on observations from the Solar Terrestrial Relations Observatory (STEREO) and ESA/NASA’s Solar and Heliospheric Observatory (SOHO), NASA said that on March 15, 2013, at 2:54 a.m. EDT, the sun erupted with a coronal mass ejection (CME) headed for Earth at speeds of around 900 miles per second.
NASA’s solar observatory, STEREO consists of two space-based observatories. One of the observatories is ahead of Earth in its orbit around the Sun with the other observatory trailing behind Earth in the same orbit. By combining observations from the two STEREO observatories, scientists gain a better picture of how solar storms form on the Sun’s surface before events emerge into space as is the case with this latest coronal mass ejection.
The SOHO observatory is a joint project between NASA and the European Space Agency. It has been sending back data on the Sun since 1995 and is designed to study the Sun’s core as well as the solar wind and the Sun’s outer corona.
The ESA and NASA Solar Heliospheric Observatory (SOHO) captured these images of the Sun spitting out...
The ESA and NASA Solar Heliospheric Observatory (SOHO) captured these images of the Sun spitting out a coronal mass ejection (CME) on March 15, 2013, from 3:24 to 4:00 a.m. EDT. This type of image is known as a coronagraph, since a disk is placed over the Sun to better see the dimmer atmosphere around it, called the corona.
NASA said that although the speed of this latest CME is at the faster end of the scale for such solar events. Historically, similar CMEs have caused mild to moderate disruption of electronic systems on Earth and Earth orbit satellites. NASA also said that with this latest CME event, there is only minor particle radiation, the factor usually associated with interfering with computer electronics on board satellites.
Earth-directed CMEs such as the recent one which eject a stream of solar particles into space have the potential to cause a geomagnetic storm once the stream collides with the magnetic fields at the outer extremes of Earth’s atmosphere, Earth’s magnetosphere. Their effects can often be seen from Earth’s surface in the form of Aurora Borealis, sometimes known as the Northern Lights. The same phenomenon exist in the Southern hemisphere, where it's called Aurora Australis.
If there are clear winter skies in the Northern Hemisphere this weekend, then there’s the potential for a spectacular display of auroras tonight and tomorrow night.