剛才去武城沒有看到 因為雲還滿多的 吃了超貴的宵夜就下山了 真是可惜 ------------------------------------------------------------------------------- The Quadrantid meteor shower is one of the year's best, producing more than 100 meteors per hour from a radiant near the North Star. This year the shower peaks on Jan. 3rd. The timing favors observers in western North America and Across the Pacific Ocean. The best time to look: during the dark hours before sunrise on Saturday morning. Although the Quadrantids are a major shower, they are seldom observed. One reason is weather. The shower peaks in early January when northern winter is in full swing. Storms and cold tend to keep observers inside. Last year, NASA scientists went to extremes to gain a good view; they flew an airplane above the clouds and over the Arctic Circle where they saw many Quadrantids: Another reason is brevity. The shower doesn't last long, a few hours at most. Even dedicated meteor watchers are likely to miss such a sharp peak. In his classic book Meteor Astronomy, Prof. A.C.B. Lovell lamented that "useful counts of the Quadrantid rate were made in [only] 24 Januaries out of a possible 68 between 1860 and 1927. ... The maximum rate appears to have occurred in 1932 (80 per hour) although the results are influenced by unfavorable weather." The source of the Quadrantid meteor shower was unknown until Dec. 2003 when Peter Jenniskens of the NASA Ames Research Center found evidence that Quadrantid meteoroids come from 2003 EH1, an "asteroid" that is probably a piece of a comet that broke apart some 500 years ago. Earth intersects the orbit of 2003 EH1 at a perpendicular angle, which means we quickly move through any debris. That's why the shower is so brief. Quadrantid meteors take their name from an obsolete constellation, Quadrans Muralis, found in early 19th-century star atlases between Draco, Hercules, and Bootes. It was removed, along with a few other constellations, from crowded sky maps in 1922 when the International Astronomical Union adopted the modern list of 88 officially-recognized constellations. The Quadrantids, which were "re-zoned" to Bootes after Quadrans Muralis disappeared, kept their name--possibly because another January shower was already widely-known to meteor watchers as the "Bootids." Got clouds? No problem. You can stay inside and listen to the Quadrantids. Tune into SpaceWeather Radio for a live audio stream from the Air Force Space Surveillance Radar. When a Quadrantid passes over the facility, you will hear a "ping" caused by the radar's powerful transmitter echoing from the meteor's ion trail. During the shower's peak, the soundtrack is guaranteed to entertain. http://www.wretch.cc/blog/nchuastro/6704590 --

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