STORM WARNING: NOAA forecasters estimate a greater than 25% chance of geomagnetic storms on June 9th. That's when a CME from the magnificent flare of June 7th is expected to deliver a glancing blow to Earth's magnetic field. High-latitude sky watchers should be alert for auroras. Aurora alerts: voice, text.
MAGNIFICENT FLARE: On June 7th at 0641 UT, magnetic fields above sunspot complex 1226-1227 became unstable and erupted. The resulting blast produced an M2-class solar flare, an S1-class radiation storm, and an unbelievable movie:
Credit: NASA's Solar Dynamics Observatory.
"It looks like someone kicked a clod of dirt in the air," says solar physicist C. Alex Young of NASA's Goddard Space Flight Center in a Youtube video. "I've never seen material released in this way before--an amazing, amazing event."
Much of the plasma thrown up by the blast simply fell back to the sun--indeed, that's what makes the footage so dramatic. In the movies you can see blobs of hot gas as large as Earth making bright splashes where they hit the stellar surface. Some plasma, however, reached escape velocity and left the sun in the form of a coronal mass ejection: movie. Traveling faster than 1100 km/s, 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.
NANOSAIL-D IN BRIGHT TWILIGHT: NASA's Nanosail-D, the first solar sail to orbit Earth, is catching the attention of evening sky watchers. "I saw it on June 3rd in bright evening twilight (sun at -7 degrees altitude)," reports Marco Langbroek of Leiden, the Netherlands. "The sky was still light blue, with the first stars visible. NanoSail-D became very bright, flashing periodically to mag. 0 with a slightly variable flash interval of 1.2 - 1.5 seconds." Look below the snapshot for a time history of the sail's brightness:
Because high-resolution photography of the small sail is so challenging, mission scientists can't be 100% sure how NanoSail-D is oriented or why it is flashing. Probably it is tumbling, with glints of sunlight producing quiasi-periodic "solar sail flares." NanoSail-D will be strobing across the evening skies of Europe and North America this week. Check the Simple Satellite Tracker or your cell phone for flyby times.
