AURORA ALERTS: Did you miss the Northern Lights? Next time get a wake-up call from Space Weather PHONE
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CLOSE ENCOUNTER WITH JUPITER: Been outside at midnight lately? There's something you really need to see. Jupiter is approaching Earth for the closest encounter between the two planets in more than a decade--and it is dazzling. Get the full story from Science@NASA.
BIG SUNSPOT: One of the biggest sunspots of new Solar Cycle 24 is rotating around the sun's southeastern limb. Presenting ... active region 1108:
Rogerio Marcon took the picture yesterday from his backyard observatory in Campinas, Brasil. Although the sunspot is big---the primary core is twice as wide as Earth--it has not yet produced any significant eruptions, only a smattering of B-flares and one C-class event. The quiet may be temporary. The sunspot's magnetic field harbors energy for major activity. NOAA forecasters estimate a 25% chance of an M-flare during the next 24 hours.
more images: from John Stetson of Portland, Maine; from Peter Paice of Belfast, Northern Ireland; from John Nassr of Baguio, Philippines; from Jo Dahlmans of Ulestraten the Netherlands; from Cai-Uso Wohler of Bispingen, Germany; from Robert Arnold of Isle of Skye, Scotland; from Peter Desypris of Syros Greece; from James Kevin Ty of Manila , Philippines
JUPITER AND URANUS: Jupiter is at opposition on Sept. 21st, meaning the giant planet will be directly opposite the sun, soaring overhead at midnight with dazzling brilliance. In a coincidence of interplanetary proportions, Uranus is at opposition on the very same night! Fredrik Broms of Kvaløya, Norway caught the two converging during a geomagnetic storm on Sept. 15th:
"It's amazing to be able to observe two giant planets next to each other--and never have I seen such a pair against a completely green background!" says Broms.
While Jupiter is outshining everything in the midnight sky (except the Moon), Uranus is barely visible to the naked eye. It's a difference of scale: Uranus is almost three times smaller than Jupiter and five times farther away. Nevertheless, Uranus is still a pretty sight. A telescope pointed at Jupiter on Sept. 21st will reveal the aqua-colored disk of Uranus less than a degree away. And if the sky turns green at the same time, well, that's just a bonus.
more images: from Jean-Paul Godard at Pic du Midi Observatory, France; from Tamas Ladanyi in the Bakony mountains of Hungary; from Peter Rosén of Stockholm, Sweden
Sept. 2010 Northern Lights Gallery
[previous Septembers: 2009, 2008, 2007, 2006, 2005, 2004, 2002, 2001, 2000]
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 18, 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 |