AURORA ALERTS: Did you miss the Northern Lights? Next time get a wake-up call from Space Weather PHONE | | |
NEW ERUPTION--UPDATE: During the waning hours of Sept. 10th, a magnetic filament erupted in the sun's northern hemisphere: SDO movie. Newly-arriving data from the Solar and Heliospheric Observatory clearly show a CME emerging from the blast site: SOHO movie. Although the CME is not heading toward Earth, the outskirts of the expanding cloud could hit our planet's magnetic field during the late hours of Sept 12th or Sept. 13th. High-latitude sky watchers should be alert for auroras.
SUNSET SKY SHOW: When the sun goes down tonight, step outside and face west. Venus and the crescent Moon are shining through the twilight in beautiful conjunction, less than 10o apart: sky map.
Tavi Greiner caught the two converging over Shallotte, North Carolina, on Sept 10th:
"The conjunction made me late for dinner," says Greiner. "I was driving to the grocery store when I caught sight of this gorgeous sunset. I turned the car around, dashed home and grabbed my camera. The grocery store will always be there, but scenes like this are few and fleeting." (See a labeled version of Greiner's photo.)
The show will be even better on Sept. 11th. Browse the links for a preview: from Mohammad Mehdi Asgari of Arak, Markazi, Iran; from Stefano De Rosa of Turin, Italy; from Kevin Jung of Grand Rapids, Michigan; from P. Nikolakakos of Sparta Greece; from James Beauchamp of Doha, Qatar; from Mojtaba Taheri of Tehran, Iran
ALIEN BEAUTY: Multiwavelength images of the sun beamed to Earth by NASA's Solar Dynamics Observatory (SDO) have a beauty that can only be described as ... alien. We've never seen the sun quite like this before. Consider the following movie of the Sept. 8th eruption of departing sunspot 1105:
SDO sees the sun through a set of extreme ultraviolet filters that go far beyond the limits of human vision. That's good because extreme UV is where the action is; it's the kind of radiation that solar activity loves to emit. But sometimes it looks a little unfamiliar.
Today's highlighted movie was created by Ralph Seguin of Lockheed-Martin's Solar and Astrophysics Lab. He combined data from three of SDO's extreme UV filters, chosing wavelengths (211 Å, 193 Å, and 171 Å) favored by plasma in the temperature range 1 to 2 million degrees K. Hot stuff! Another movie at 304 Å shows cooler gas, around 80,000 K. By comparing the hot movie vs. the cool movie, researchers hope to learn much about the underlying physics of the eruption.
Look for more alien beauty at NASA's SDO home page.
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 11, 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 |