SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
COMET HARTLEY 2 UPDATE: Comet Hartley 2 is now about 11 million miles from Earth, one of the closest approaches of any comet in the last few centuries. Unfortunately, the Moon is waxing full at the same time. Glaring moonlight will make the comet difficult to observe for the next week at least. Indeed, the next great shot you see might come from EPOXI.
SUNDIVING COMET: How much longer can it last? A newly-discovered comet is diving toward the sun, and it probably won't survive the encounter. Click on the image to view a 5 MB movie of the ongoing death plunge:
Chinese comet hunter Bo Zhou found the sundiver on Oct. 19th in SOHO coronagraph images. Heated by intensifying solar radiation, the icy comet has brightened 100-fold since Zhou's discovery to approximately 1st magnitude. If this comet were in the night sky, it would be a spectacular sight. Instead, it will probably be destroyed behind the opaque disk of SOHO's coronagraph as it attempts to swing around the sun at all-too-close quarters.
The comet is likely a member of the Kreutz sungrazer family. Named after a 19th century German astronomer who studied them in detail, Kreutz sungrazers are fragments from the breakup of a giant comet at least 2000 years ago. Several of these fragments are thought to pass by the sun and disintegrate every day. Most are too small to see but occasionally a big fragment like this one attracts attention.
ORIONID METEOR SHOWER: Earth is entering a broad stream of debris from Halley's Comet, and this is causing the annual Orionid meteor shower. "The best time to look is during the hours before dawn on Thursday, Oct. 21st, and again on Friday, Oct 22nd," advises Bill Cooke of NASA's Meteoroid Environment Office. "Unfortunately, we have a bright Moon this year. Even so, I'd expect some bright Orionids to shine through the moonlight." An all-sky camera at the University of Western Ontario recorded this early Orionid fireball on Oct. 18th:
Orionid meteors stream from the elbow of Orion the Hunter: sky map. Because the shower's radiant point is close to the celestial equator, sky watchers in both hemispheres can enjoy the show. Moonlit meteor rates will probably be around a dozen per hour.
Radar rates could be much higher. The US Air Force Space Surveillance Radar in Texas is scanning the skies for satellites, space junk, and meteoroids. When an Orionid passes overhead--ping!--there is an echo. Moonlight does not interfere with this method of meteor observing, so it's perfect for this year's Orionids. Tune into Spaceweather Radio for live echoes.
Orionid images: from John Chumack of Dayton, Ohio; from Calvin Hall of Knik Valley, near Palmer Alaska; from Martin Popek of Nýdek, Czech republic
Comments
Post a Comment