NEW AND IMPROVED: Turn your iPhone or iPod Touch into a field-tested global satellite tracker. The Satellite Flybys app now works in all countries. | | | GEOMAGNETIC STORM: A sharp gust of solar wind hit Earth's magnetosphere on April 5th and sparked the strongest geomagnetic storm of the year (Kindex=7). Although the storm is subsiding now, it is not over. High-latitude sky watchers should remain alert for auroras. [UPDATED: gallery]. UNIQUE LIFTOFF: Veteran observers agree, yesterday's launch of space shuttle Discovery was something special. "I've seen some truly spectacular shuttle launches since Columbia first rocketed into space in 1981, but the launch of STS-131 was in a whole new category," says Jonathan Sabin of Ellenton, Florida. He took this picture and explains the elements of it below: 
"Standing alone at the edge of a deserted cow pasture, I watched in awe as the craft first appeared over a line of trees about a quarter mile away. I was transfixed by the towering, backlit exhaust plume," says Sabin. "Next, something happened that I had never witnessed before. About half-minute or so after the solid rocket boosters (SRBs) separated, a plume appeared around the craft itself. A moving, nebulous 'blob' expanded and twisted as Discovery arched its way back toward the horizon en route to orbit." The show continued even after the shuttle was out of sight. Ice crystals in Discovery's lingering exhaust caught the rays of the rising sun and formed a noctilucent cloud of startling brightness. "In all my 30 years of watching noctilucent clouds, I never have seen one like this," says astronomer Jacob Kuiper, who got a close-up view of the phenomenon from the Kennedy Space Center's Press Site. "The shuttle exhaust plume turned into a magnificent panorama of color." more images: from Doug Shytle, PhD of Cape Canaveral, Florida; from Pete Lardizabal of Canaveral National Seashore Park, FL; from Dan Gore of Titusville, Florida; from William Hartenstein of Kennedy Space Center, FL; from Chuck Pek of Cocoa Beach, Florida; from Jacob Kuiper at the Kennedy Space Center's press site; from Mark Staples of Waldo, Florida; from George Fleenor of Bradenton, FL; from Anna Herbst on the NASA Causeway, Titusville, FL; from Terry Allshouse of Leesburg, Florida; from Jim Burchfield of Saint Cloud, Florida; from Adam Bojanowski of Oviedo, Florida; from Jeremy Judkins of Clearwater, Florida; NORTHERN SPRING: Normally, watching auroras north of the Arctic Circle is a chilling experience, but since Spring arrived, it hasn't been so bad. "Last night, a geomagnetic storm hit our area with full force, producing some of the nicest--and warmest--auroras in months," reports Fredrik Broms of Kvaløya, Norway. "Never before have I been able to watch auroras without freezing. This is a completely new experience to me." 
Photo details: Nikon D3, Nikkor 20mm, f/2.8, 2 sec at ISO 800
He snapped the picture above using a Nikon D3. "The sky doesn't get any more beautiful than this," says Broms. Or does it? A solar wind stream is due to hit Earth tonight or tomorrow, re-energizing and possibly intensifying the display. Northern sky watchers should go outside and look; it's not so cold, after all. UPDATED: April Northern Lights Gallery
[previous Aprils: 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002] | 
