SEVERE STORM WARNING CANCELLED: NOAA forecasters have downgraded the chance of a severe geomagnetic storm on Oct. 25th to only 1%. Nevertheless, high-latitude sky watchers should remain alert for auroras as a solar wind stream continues to buffet Earth's magnetic field.
SPACE STATION FLYBYS: For the next week, the International Space Station (ISS) will be performing a series of bright evening flybys over North America and Europe. The station is very easy to see if you know when to look. Check the Simple Satellite Tracker for local flyby times or you can turn your cell phone into a field-tested ISS-tracker.
On Oct 21st, amateur astronomer Béla Vingler of Győrújfalu, Hungary, caught the space station flying directly in front of the Moon:
Photo details: 12-inch reflecting telescope, Canon 400D, ISO 800, 1/3200 exp.
The station's winged outline was backlit by the bright debris fields of Crater Tycho as the spacecraft raced across the lunar disk, completing the transit in only a split-second. Because lunar transits happen so fast, careful planning is required to photograph them. The place to start is Calsky.com, which provides precise predictions of ISS transits for locations around the world.
MOON RINGS: It's not uncommon to see one ring around the Moon. But two? On Oct. 23rd, Martin Popek of Nýdek, Czech republic, photographed a rare pair:
The outer 22o circumscribed halo is caused by moonlight shining through six-sided pencil-shaped ice crystals in the air. This is a familiar sight to backyard sky watchers. Less familiar is the 9o inner ring. It is caused by ice crystals with a strange pyramidal shape. The 9o ring is the innermost of many possible "odd-radius" halos caused by pyramidal ice crystals. Atmospheric optics expert Les Cowley notes that "pyramidal crystals [might not be as] rare as previously thought" and he urges sky watchers to "search carefully for their halos whenever the skies look favourable."
more images: from Denis Joye of Boulogne, France;
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 24, 2010 there were 1155 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 |