After a long quiet spell without any strong solar storms, on July 7, 2007 the Sun unleashed a flare (M-class, which means moderate) and a fairly substantial coronal mass ejection (CME). As seen in these four coronagraph images that span about three hours, a bright cloud of particles was blasted into space. Its source was the large sunspot at active region 10898. These storms carry billions of tons of matter at millions of miles per hour. These CME clouds of energized particles may reach the Earth in two to three days, creating the possibility of some brilliant aurora displays further down from the North and South Polar regions than usual. Sometimes they can also create communication, navigation and satellite problems. However, in this case, due to its sharp angle off to the right, it is quite unlikely that we will experience any effects from this storm.

In coronagraph images, an occulting disk blocks out the Sun and some of the area beyond it creating something like an artificial solar eclipse. The size of the Sun is represented by the white circle.

Previous Picks of the Week

SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.

If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to steele.hill@gsfc.nasa.gov.