UPDATE - 06.10.11:The CME from Tuesday's spectacular flare still hasn't reached Earth. NOAA forecasters estimate a 20-30% chance that the cloud may yet deliver a glancing blow to our planet's magnetic field and spark geomagnetic storms during the next 24 hours. High latitude sky watchers should remain alert for auroras.
Also, the two STEREO video have been replaced with better quality versions. Check them out.
06.07.2011 - Having a Solar Blast
The Sun unleashed an M-2 (medium-sized) solar flare, an S1-class (minor) radiation storm and a spectacular coronal mass ejection (CME) on June 7, 2011 from sunspot complex 1226-1227. The large cloud of particles mushroomed up and fell back down looking as if it covered an area of almost half the solar surface.
The Solar Dynamics Observatory (SDO) observed the flare's peak at 1:41a.m. ET (0641 UT). SDO recorded these images (above) in extreme ultraviolet light that show a very large eruption of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material -- at temperatures less than 80,000 K.
All of the solar Heliophysics System Observatory missions captured the event.
When viewed in Solar and Heliospheric Observatory's (SOHO) coronagraphs (top right), the event shows bright plasma and high-energy particles roaring from the Sun.
Also to the right are links to the Solar Terrestrial Relations Observatory (STEREO) Ahead and Behind coronograph videos showing the CME expansion as viewed from each side of the sun. The STEREO Ahead satellite precedes the Earth as it circles the Sun. The STEREO Behind satellite follows behind the Earth in it's orbit of the Sun.
This not-squarely Earth-directed CME is moving at 1400 km/s according to NASA models. The CME should deliver a glancing blow to Earth's magnetic field during the late hours of June 8th or June 9th. High-latitude sky watchers should be alert for auroras when the CME arrives.
What is a solar flare? What is a CME?
For answers to these and other space weather questions, please visit the Spaceweather Frequently Asked Questions page.