AURORA ALERTS: Did you miss the Northern Lights? Next time get a wake-up call from Space Weather PHONE
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AURORA WATCH: High-latitude sky watchers should be alert for auroras on Sept. 12th and 13th. That's when a coronal mass ejection (CME) is expected to deliver a glancing blow to Earth's magnetic field. NOAA forecasters estimate a 30% chance of geomagnetic activity during the next 24 hours. Updated: aurora gallery.
PARTING OF THE RED SEA: The source of the incoming CME is a magnetic filament on the sun, which erupted during the late hours of Sept. 10th. NASA's Solar Dynamics Observatory recorded the blast:
Movie formats: 1.3 MB mpg, 0.8 MB m4v, 0.9 MB avi
Shortly after the filament erupted, the plasma sea underneath it seemed to open a fiery-red fissure. This is a common manifestation of explosions on the sun. In the aftermath of a flare, magnetic loops form over the blast site. Hot plasma sliding down the sides of these loops hits the stellar surface, creating a light show that resembles a "parting of the red sea."
No fewer than three spacecraft (STEREO-A, STEREO--B, and SOHO) observed a coronal mass ejection (CME) emerging from the blast site: SOHO movie. An analysis of the CME from multiple points of view suggests that a portion of its southern flank was Earth-directed. People in Alaska, Canada, Iceland, Greenland and Scandinavia could see Northern Lights when the cloud arrives on Sept 12th or 13th. Stay tuned!
VENUS AND THE MOON: Around the world on Sept. 11th, sky watchers marveled as Venus and the Moon converged for a beautiful close encounter. In South Africa, it was a full-fledged occultation. "The Moon passed directly in front of Venus, completely covering the planet," reports Kerneels Mulder. "I was lucky enough to capture a series of images as Venus re-appeared from behind the Moon in broad daylight." See below:
Take a close look at Venus in the full-sized composite. Like the Moon, Venus has phases, and on Sept. 11th it was only 35% illuminated. With the Moon itself at 19%, this was a close encounter of crescents.
Other, less-close encounters were equally beautiful. Browse the links for global examples: from Aymen Ibrahem of Giza, Egypt; from M. Raşid Tuğral of Mogan Lake, Ankara-Turkiye; from Stefano De Rosa of Viverone Lake, Italy; from Gustavo Rojas of Passa Quatro, Brazil; from Moulley Charaf Chabou of Algiers, Algeria;
UPDATED: 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 12, 2010 there were 1144 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 |