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.
| || |
THE SECRET LIVES OF SOLAR FLARES: NASA-supported researchers say that solar flares have been keeping a secret. The new finding, reported in the Oct. 1st issue of the Astrophysical Journal, suggests that explosions on the sun could affect Earth even more than previously thought. [full story]
FOUR CMEs: On Sept. 19th, the STEREO-SOHO fleet of spacecraft surrounding the sun detected six coronal mass ejections (CMEs). Two of the clouds rapidly dissipated. The remaining four, however, are still intact and billowing through the inner solar system. Click to view a movie of their forecasted paths:
According to analysts at the Goddard Space Weather Lab, who prepared the movie, one CME should hit Mercury on Sept. 20th at 05:40 UT while another delivers a glancing blow to Earth's magnetic field on Sept. 22th at 23:00 UT. All impact times have an uncertainty of plus or minus 7 hrs.
High-latitude sky watchers (on Earth) should be alert for auroras when the CME arrives. Aurora alerts: text, voice.
September 2011 Aurora Gallery
[previous Septembers: 2010, 2009, 2008, 2007, 2006, 2005, 2004]
RE-ENTRY ALERT: NASA reports that UARS, an atmospheric research satellite the size of a small bus, will re-enter Earth's atmosphere on Sept. 23rd plus or minus one day. The disintegration is expected to produce a fireball that could be visible even in broad daylight. Not all of the spacecraft will burn up in the atmosphere, however; according to a NASA risk assessment, as many as 26 potentially hazardous pieces of debris could be scattered along a ground track some 500 miles long. But where? No one can say. Because of the rapid evolution of UARS's decaying orbit, the location of the debris zone is not yet known. Stay tuned for improved predictions as the moment of re-entry nears.
On Sept. 15th, astrophotographer Theirry Legault video-recorded the doomed satellite during one of its last passes over France:
Photo details: Celestron 14" EdgeHD, Takahashi EM400 mount modified for fast tracking. Range to UARS: 252 km.
"The satellite appears to be tumbling, perhaps because a collision with satellite debris a few years ago," notes Legault. "The variations in brightness are rapid and easily visible to the human eye." (Other observers have reported UARS flashes almost as bright as Venus.)
For last-chance sightings of this brightly flashing satellite, please check the Simple Satellite Tracker or download the Satellite Flybys app for your smartphone.