SUNSPOT MOVIE: A new movie from NASA's Solar Dynamics Observatory shows behemoth sunspot 1117 growing and shape-shifting between Oct. 25th and 27th. Transmogrify!
ASTEROID FLYBY: Asteroid 2003 UV11 is about to fly past Earth. At closest approach on Oct. 29th and 30th, it will be only 1.2 million miles away, about five times the distance to the Moon. Experienced amateur astronomers should have little trouble photographing the 600-meter wide space rock as it glides through the constellation Pegasus on Friday night glowing about as brightly as a 12th magnitude star. NASA's Goldstone and Arecibo radars are pinging the asteroid as it passes to study its shape and trajectory. Stay tuned for updates. [images: #1, #2, #3] [ephemeris] [3D orbit]
SUNSPOT SUNRISE: Sunspot 1117 is now so large, it can be seen without the aid of a solar telescope. Mohamad Soltanolkottabi "spotted it" this morning when the sun was rising over Esfahan, Iran:
"I took this photo while climbing up Sofe mountain," says Soltanolkottabi. "It was a good way to start the day."
Although the sunspot is big--its primary core is four times wider than Earth--it is also quiet. The sunspot's magnetic field has relaxed into an uncomplicated state that seems to pose little threat for solar flares. There is, however, a high probability of photo-ops. Stay tuned.
more images: from Francois Rouviere of Mougins, France; from Matt Wastell of Brisbane, Australia; from Rogerio Marcon of Campinas SP Brasil; from John Chumack of Dayton, Ohio;
GIANT SUN TWISTER: On Oct. 27th and 28th, a twisted filament of magnetism on the sun decided to untwist. The result was a spectacular eruption recorded in full-disk detail by NASA's Solar Dynamics Observatory:
Movie formats: 8 MB gif, 3 MB gif, 1.7 MB iPad, 0.7 MB iPhone
At its peak, the twister--or rather, untwister--towered more than 350,000 km above the stellar surface. It appears to have hurled a fragment of itself into space, but not toward Earth; the blast was not geoeffective.
Now that the filament has relaxed, it is unlikely to erupt again. The next blast is more likely to come from big sunspot 1117, which NOAA forecasters say could produce an M-class solar flare. Readers with solar telescopes are encouraged to monitor developments.
CRESCENT PLANET: This week, Venus is passing almost directly between Earth and the sun, an event astronomers call "inferior conjunction." As Venus turns its night side toward us, we can see only the thinnest sliver of the planet's atmosphere illuminated by sunlight. Venus has become a slender crescent.
On Oct. 24th, Günther Strauch peered through a 4-inch refracting telescope and witnessed the crescent planet shimmering through clouds over Borken, Germany.
Click to view the full-length movie
"Wow, what a nice view!" says Strauch. "I had to be very careful because Venus was only 10 degrees from the sun. Furthermore, it was not easy to find the planet because of the clouds, but the final result was worth the effort."
Venus is even closer to the sun now, making sightings truly perilous. Fortunately, a coronagraph onboard the Solar and Heliospheric Observatory is able to block the sun's glare and monitor the conjunction in progress. Click here for the latest; Venus is the super-bright object just below the sun.
more images: from Joe Ricci of Rochester, New York; from Henry Mendt of Maracaibo, Venezuela
October 2010 Aurora Gallery
[previous Octobers: 2009, 2008, 2007, 2006, 2004, 2003, 2002, 2001]
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 October 29, 2010 there were 1157 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 |
| ||the underlying science of space weather |