Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift. | | |
WHAT LIES INSIDE JUPITER?The clouds of Jupiter hide many mysteries--from the roots of monster storms to possible stores of exotic matter. NASA's Juno spacecraft, scheduled to launch on August 5th, is going to find out what lies inside the giant planet. [full story] [video]
GEOMAGNETIC ACTIVITY: A solar wind stream is buffeting Earth's magnetic field and causing intermittent geomagnetic activity around the poles. The peak so far has been a G1-class storm that lasted for several hours around the end of July 30th. "I received a storm alert from Space Weather Phone," says Bob Johnson of Saskatoon Saskatchewan. "When I dashed outside, there were big-time auroras." He recorded the scene in this 25-second exposure:

NOAA forecasters estimate a ~20% chance of more such storms on July 31st as the solar wind continues to blow. High-latitude sky watchers should remain alert for auroras especially in the southern hemisphere where skies are winter-dark. Aurora alerts: text, voice.
July 2011 Aurora Gallery
[previous Julys: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003]
SOLAR FLARE: Sunspot AR1261 unleashed a brief but powerful solar flare on July 30th at 0209 UT. Registering M9 on the Richter Scale of Flares, the blast almost crossed the threshold into X-territory (X-class flares are the most powerful kind). NASA's Solar Dynamics Observatory recorded the flare's extreme ultraviolet flash:

Because of its brevity, the eruption did not hurl a substantial cloud of material toward Earth. No CME is visible in SOHO coronagraphs. The eruption was not geoeffective, although future eruptions could be as the active region continues to turn toward Earth. Solar flare alerts: text, voice.
TODAY'S BONUS SHOTS: Hubble Transits Jupiter from Tom Harradine of Brisbane, Australia; Electric Blue Clouds from Tuomas Mäkynen of Hirvensalmi, Central Finland; Sunspot Sunset from Don Roberts of Wintersville, Ohio; Fireballs! from Yuichi Takasaka of British Columbia, Canada
BIG SUNSPOTS: The finest display of sunspots since 2006 is underway. Three behemoth sunspot groups are transiting the sun's northern hemisphere, shown here in a July 31st image from NASA's Solar Dynamics Observatory:

Among the three, sunspot 1261 is most active. The multi-cored group has a beta-gamma-delta class magnetic field that harbors energy for X-class solar flares. Readers with solar telescopes are encouraged to monitor developments.
more images: from Alan Friedman of Buffalo, NY; from Göran Strand of Froson, Sweden; from Michael Borman of Evansville, Indiana; from Neo of The Netherlands; from Ehsan Rostamizadeh of Kerman, Iran; from Steve Riegel of Albuquerque, NM;
2011 Noctilucent Cloud Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009]