Where's Saturn? Is that a UFO--or the ISS? What's the name of that star? Get the answers from mySKY--a fun new astronomy helper from Meade. . MARS UPDATE: Two months after sky-darkening dust from severe storms nearly killed NASA's Mars exploration rovers, the solar powered robots are alive and well and ready to continue their missions. Next up: Opportunity begins its risky descent into Victoria crater on Sept. 11th: more. AURORA SEASON: It's September, and that means aurora season is underway. For reasons not fully understood, the weeks around the autumnal equinox (Sept. 23) produce more geomagnetic storms than any other time of year. Even the mildest solar wind stream brushing against Earth can ignite auroras: Photo details: Canon 5D, ASA 800, 20 seconds exposure. "What a beautiful night," says Erkki Rauhala who took this picture from Uurainen, Finland, on Sept. 6th, typical of many recent sightings in that part of the world. Most of the displays ahead will be confined to Scandinavia, Alaska and Canada, but don't be surprised if Northern Lights descend to mid-latitude US states such as Maine, Wisconsin, Minnesota, and Washington. 'tis the season! The next solar wind stream is due on Sept. 14th. Sky watchers, be alert for auroras. September 2007 Aurora Gallery [August 2007 Aurora Gallery] [Night-sky Cameras] BISHOP'S RING: "I stepped outside of work at 4:00 pm today, and noticed a rather bright blue aureole around the sun with a radius similar to a garden variety solar halo, bordered by a faint yellowish corona," says Doug Zubenel of Johnson County, Kansas. "The darkness of the photo's corners is due to the drop in brightness of the sky outside the halo - no vignetting from the lens is occurring at all." (continued below) Photo details: Nikon FM2, 16mm Nikkor fisheye lens, f/8, 1/500 sec, Fuji Velvia 50 This phenomenon is called a Bishop's Ring. "It is essentially a corona produced by very small (1 micron or less) particles or droplets," explains atmospheric optics expert Les Cowley. "A large volcano injecting fine ash into the stratosphere can produce these effects for years." There haven't been any big eruptions lately. Instead, suggests Cowley, this Bishop's Ring may have been caused by a distant wildfire wafting its ash over middle America. "We shall likely never know!" he says. Consider it a beautiful mystery. more images: from Martin Popek of the Czech Republic. |