AURORA ALERTS: Did you miss the Northern Lights? Next time get a wake-up call from Space Weather PHONE | | |
COMET PHOTO OP: Comet Hartley 2 is a fine target for backyard telescopes--and it is about to become even finer. On Oct. 7th and 8th the comet's vast green atmosphere will pass barely 1o from the photogenic Double Cluster in Perseus. Details and a sky map are available from from Sky & Telescope.
AURORAS AND LASERS OVER GREENLAND: On Oct. 5th, the interplanetary magnetic field (IMF) near Earth tipped south and temporarily punctured our planet's magnetosphere. Solar wind poured in and fueled this display over Greenland:
Ed Stockard reports from the National Science Foundation's Summit Observatory, 11,000 feet atop the Greenland ice sheet: "We are experiencing clear skies and cooler temperatures here at the summit. These pictures were taken at our Mobile Science Facility where a project named ICECAPS has several instruments studying Arctic clouds. The experiment's lidars (green laser radars) may be seen lancing up into the auroras. The reds on the snow are reflections from a nearby beacon on a fifty meter tower."
"Did I mention cooler temps?" he adds. "The thermometer read -42 C."
Another display could be in the offing. A minor solar wind stream is expected to hit Earth's magnetic field on or about Oct. 9th, possibly sparking geomagnetic activity. Arctic researchers should stay warm and be alert for auroras.
A SUNSPOT SHAPED LIKE A SPACESHIP: The Earth-facing side of the sun is blank. Nevertheless, on Monday, Oct. 4th, Theo Ramakers and Frank Garner of Social Circle, Georgia, managed to find a sunspot--and it looked a lot like the International Space Station:
Indeed it was the silhouette of the ISS making a split-second transit in front of the sun.
"We were lucky to catch it," says Ramakers. The problem was not so much that the transit was fast, but rather that it was so cloudy. "When we started observing, a cloud was in the way. Just in time, however, the cloud got thinner and we managed to get the transit while the cloud was moving off the sun."
Observers who wish to find their own space station-shaped sunspots this week should check Calsky.com for local transit predictions.
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 October 6, 2010 there were 1149 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Mag. | Size |
1999 VO6 | Oct 14 | 34.3 LD | 16.9 | 1.8 km |
2010 TK | Oct 16 | 4.5 LD | 25.3 | 39 m |
1998 TU3 | Oct 17 | 69.1 LD | 14.6 | 5.2 km |
1998 MQ | Oct 23 | 77.7 LD | 16.7 | 1.9 km |
2007 RU17 | Oct 29 | 39.2 LD | 18 | 1.1 km |
2003 UV11 | Oct 30 | 5 LD | 19.3 | 595 m |
3838 Epona | Nov 7 | 76.8 LD | 15.5 | 3.4 km |
2005 QY151 | Nov 16 | 77.7 LD | 17.6 | 1.3 km |
2008 KT | Nov 23 | 5.6 LD | 28.2 | 10 m |
2002 EZ16 | Nov 30 | 73.9 LD | 18.2 | 1.0 km |
2000 JH5 | Dec 7 | 47 LD | 17.3 | 1.5 km |
2010 JL33 | Dec 9 | 16.6 LD | 17.6 | 1.3 km |
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 |