AURORA ALERTS: Did you miss the Northern Lights? Next time get a wake-up call from Space Weather PHONE
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CRESCENT PLANET: When the sun sets this evening, look low and west for Venus beaming through the twilight. A telescope pointed at the bright Evening Star will reveal a delicate crescent. Venus has phases and it is now only 22% illuminated. Recent images: #1, #2, #3, #4.
A MAGIC NIGHT IN GREENLAND: A solar wind stream buffeted Earth's magnetic field over the weekend, sparking Northern Lights around the Arctic Circle. Ed Stockard sends this report from the National Science Foundation's Summit Observatory, 11,000 feet atop the ice sheet in Greenland: "We've had cloudy weather for nearly six weeks. A long-awaited clear night on Sept. 25th brought out the auroras--shown here over an elevated structure we call 'the Big House.'"
View the complete panorama
Auroras, however, were only a fraction of the show. "I stitched together five images to create a panorama," says Stockard. "It shows the Harvest Moon, Jupiter, auroras over the Big House and a lunar fogbow 180o from the moon. Magical!"
Another solar wind stream could brush against Earth's magnetic field on Sept. 29th. Sky watchers on the ice sheet and elsewhere around the Arctic Circle should remain alert for auroras.
UPDATED: Sept. 2010 Northern Lights Gallery
[previous Septembers: 2009, 2008, 2007, 2006, 2005, 2004, 2002, 2001, 2000]
TRIPLE RAINBOW: Double rainbows are commonplace. Sunlight reflected once inside raindrops produces the primary arc; sunlight reflected twice produces the secondary. Most people who have seen a single rainbow, have also seen a double.
But have you ever seen a triple? Daryl Pederson of Anchorage, Alaska, spotted one on Sept. 20th:
"Here's something you don't see every day--three rainbows at once!" says Pederson. "The bonus third rainbow was caused by an image of the sun reflected from Potter's Marsh into the falling rain above."
Three rainbows is not the record, however. Atmospheric optics expert Les Cowley has documented cases of four, five and even six bows in the same scene. Read all about them here.
more images: from Calvin Hall of Beluga Point near Anchorage Alaska; from John Maynard of Mt. Rushmore, South Dakota; from Jeff Berkes of Kilo, Hawaii; from Marko Korosec of Dolenja vas, Senozece, Slovenia, Europe; from Alan Dyer of Cluny, Alberta, Canada; from Slanec Erich of Vienna, Austria
Potentially Hazardous Asteroids (PHAs
) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones
all the time.
On September 27, 2010 there were 1145 potentially hazardous asteroids. Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.
| ||The official U.S. government space weather bureau |
| ||The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| ||Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| ||3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| ||Realtime and archival images of the Sun from SOHO. |
| ||from the NOAA Space Environment Center |
| ||from the National Solar Data Analysis Center |