DISCOVERY POSTPONED: Bad weather in Florida has delayed the launch of space shuttle Discovery one more day. Liftoff is now scheduled for Friday, Nov. 5th, at 3:03 pm EDT. Check the launch blog for updates.
COMET ENCOUNTER UPDATE: This morning, NASA's Deep Impact (EPOXI) probe flew past Comet Hartley 2 only 435 miles from the comet's active nucleus. The spacecraft has since turned its high-gain antenna toward Earth and data are being transmitted to mission control at JPL. Even without processing, the first raw images are spectacular:
The first five close-up images: #1, #2, #3, #4, #5
UPDATE: At a press conference on Thursday afternoon, mission scientists discussed their first impressions. The comet has a dumbbell shape, they noted, with rough ends and a smooth middle. Jets come from rough terrain and seem to be correlated with specific topographic features. The middle is covered with some kind of fine dusty material that has collected in a topographic low point.
The images reveal a comet bristling with gaseous jets--even on the comet's nightside where volatile ices are temporarily protected from solar heating. Distinct lines of jets trace the comet's day-night terminator. Researchers again expressed their amazement at Comet Hartley 2's hyperactivity.
Stay tuned for more as the analysis continues.
FARSIDE FLARES--MORE TO COME? An active sunspot is about to emerge over the sun's southeastern horizon. It announced itself yesterday with a C4-class flare that hurled material high above the stellar surface, shown here in a movie from NASA's Solar Dynamics Observatory:
movie formats: 3.8 MB mpeg, 0.9 MB iPad, 0.3 MB iPhone
Although the explosion happened behind the limb of the sun, it nevertheless yielded enough x-radiation to produce a wave of ionization in Earth's upper atmosphere. Researcher Rob Stammes recorded a sudden ionospheric disturbance (SID) when the wave passed over his lab in Laukvik, Norway. (Learn more about SIDs here.) Without even showing itself, the sunspot is already geoeffective.
The source of this activity appears to be old active region 1112. It crossed the Earth-facing side of the sun back in October, a sunspot dragging a magnificent filament of magnetism behind it. Two weeks later, AR1112 t is coming around for a second pass. Yesterday's eruption may be read as "hello, I'm back." Readers with solar telescopes are encouraged to monitor developments.
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 November 4, 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 |