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METEORS FROM HALLEY'S COMET: Earth is entering a streaam of debris from Halley's Comet, source of the annual eta Aquarid meteor shower. People who wake up before sunrise on Friday morning, May 6th--that's tomorrow morning--could see between 10 and 40 meteors per hour as bits of Halley's comet disintegrate in the atmosphere. [full story] [video] [meteor radar] [NASA chat]
SUNSET SKY SHOW: When the sun goes down tonight, step outside and look west. An exquisite crescent Moon is beaming through the twilight:
The sight moved Tavi Greiner of Shallotte, NC, who took the picture on May 4th, to wax poetic: "I spy, in the twilight sky, the young Crescent Moon, with 37 Tauri."
More verse could be in the offing tonight, May 5th, when the crescent fattens slightly to 6% and appears higher above the horizon for even easier viewing. Check the sunset sky for inspiration.
more images: from Marek Nikodem of Szubin, Poland; from Mohammad Mehdi Asgari of Zanjan, Iran; from Jan Koeman of Kloetinge, the Netherlands; from Monika Landy-Gyebnar of Veszprem, Hungary; from Alan C Tough of Elgin, Moray, Scotland
ASTEROID FLYBY: Asteroid 2003 YT1 is flying past the Earth-Mooon system today at a safe distance of 25 million km. Albeit far away, the 2.5 km-wide space rock is big enough to see through backyard-class telescopes. At the University of Narino Observatory in Columbia, Alberto Quijano Vodniza and colleagues used a 14-inch Meade LX200 to record this movie:
Experienced observers can track 2003 YT1 in the nights ahead as it slowly crosses the zodiac near Cancer. Sunlight reflected from the asteroid's surface makes it shine like a 15th-magnitude star--an easy target for telescopes equipped with sensitive CCD cameras. [3D Orbit] [ephemeris]
April 2011 Aurora Gallery
[previous Aprils: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]
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 May 5, 2011 there were 1218 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.
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| ||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 |
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