“Meteor Shower and Total Lunar Eclipse to Wow Skywatchers This Month - YAHOO!” plus 1 more |
| Meteor Shower and Total Lunar Eclipse to Wow Skywatchers This Month - YAHOO! Posted: 08 Dec 2010 03:16 PM PST Skywatchers, grab your blankets. December's night sky spectacular will feature the best meteor shower of 2010 as well as the only total lunar eclipse of the year -- sights that should outshine any New Year's Eve fireworks display in terms of sheer wonder. The massive Geminid meteor shower returns every year, so you'll have more chances if the cold proves too daunting on the night of Dec. 13. But anyone in North America who skips the total lunar eclipse on the night of Dec. 20 will be missing what promises to be the best lunar eclipse show until April 2014. [Local guides: The best spots to stargaze in your area] This year's Geminid meteor shower is expected to be the best display of so-called "shooting stars" of the year and will peak during the overnight hours of Dec. 13 and Dec. 14. Dazzling Geminid meteor shower Like most meteor showers, the Geminids will be at their best after midnight (early on the morning of Dec. 14), when the Earth is heading directly into the meteoroid stream. But some will be visible earlier in the night, on the evening of Dec. 13, because the meteors' radiant (where they appear to originate) is nearly circumpolar, so they will stay in view above the horizon all night. [See also: Scientists cry foul over NASA 'life form' find] This sky map shows where to look to see the Geminid meteor shower in the direction of the constellation Gemini. Clear dark skies, of course, promise the best viewing conditions. Anyone venturing outside should dress much more warmly than normal to prepare for a long night vigil while sitting still. Don't forget to get comfortable: A lawn chair with a reclining back and a blanket or sleeping bag should keep skywatchers snug — no binoculars or telescope are necessary. Most meteor showers are caused by fragments of old comets scattered along a comet's orbit. When the Earth passes through a comet's orbit, it sweeps up the fragments, which become visible as bright streaks of light in the atmosphere. The Geminid shower is unique in being associated not with a comet, but with an asteroid called 3200 Phaethon. The Geminids' radiant is, as the name implies, in the direction of the constellation Gemini, just north of the northernmost of Gemini's two brightest stars, Castor and Pollux. In the early evening of Dec. 13, the radiant is low in the northeast. By 1 a.m. EST, after the date has changed to Dec. 14, the radiant is almost directly overhead. By 6.a.m. EST, when the shower is at its peak in the Eastern Time Zone, the radiant is low in the west. Moon's holiday treat The December holiday sky show doesn't end with the Geminid meteor shower. On the nights of Dec. 20 and Dec. 21, parts of four continents will be treated to a total eclipse of the moon — the only one to occur in 2010. This NASA lunar eclipse chart shows the visibility of the eclipse from different regions around the world. The last total lunar eclipse occurred on Feb. 20, 2008. While there are two total lunar eclipses in 2011, North American skywatchers will have to wait until April 2014 for one as potentially spectacular as the eclipse occurring this month. [Amazing Total Lunar Eclipse Photos] Lunar eclipses occur when the moon passes through a point in its orbit in which the Earth is directly between it and the sun. When the moon enters the shadow of Earth, it creates a lunar eclipse. Unlike a solar eclipse, no precautions to protect the eyes are needed. A total lunar eclipse is when the entire moon is completely inside the Earth's shadow. Since the sun's rays are bent by Earth's atmosphere so that some still reach the moon, the moon is still visible in an eclipse. Lunar eclipse skywatching tips For the Western Hemisphere, the eclipse will "officially" begin on Dec. 21 at 12:29 a.m. EST (9:29 p.m. PST on Dec. 20) as the moon begins to enter Earth's outer, or penumbral, shadow. As for the Geminid meteor shower, don't forget to dress warm. But you won't be outside all night moongazing. This total lunar eclipse lasts only 72 minutes from start to finish. [Related: Where, how astronomers could find alien life] But even in clear weather, skywatchers will not notice any changes in the moon's appearance until about 45 minutes into the event, when a slight "smudge," or shading, begins to become evident on the upper left portion of the moon's disk. The entire total lunar eclipse will be visible from all of North and South America, the northern and western parts of Europe, and a small part of northeast Asia, including Korea and much of Japan. Totality will also be visible in its entirety from the North Island of New Zealand and Hawaii. In all, an estimated 1.5 billion people will have an opportunity to enjoy the best part of this lunar show. In other parts of the world, only the partial stages of the eclipse will be visible or the eclipse will occur when it's daytime and the moon is not above their local horizon. [See also: Japan space probe shoots past Venus] Portions of western Africa and central Europe can catch the opening stages of the eclipse before the moon sets below the horizon during the morning hours of Dec. 21, while the eastern third of Asia and central and eastern Australia can catch the closing stages just after moonrise on the evening of Dec. 21. December's total lunar eclipse and Geminid meteor shower promise to ring the year 2010 out with a dazzling show, weather permitting, this holiday season. But bundle up and stay warm! SPACE.com Skywatching columnist Joe Rao and Starry Night Software's Geoff Gaherty contributed to this December skywatching tips report. SPACE.com offers rich and compelling content about space science, travel and exploration as well as astronomy, technology, business news and more. The site boasts a variety of popular features including our space image of the day and other space pictures,space videos, Top 10s, Trivia, podcasts and Amazing Images submitted by our users. Join our community, sign up for our free newsletters and register for our RSS Feeds today!Other popular stories on Yahoo! 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| Geminid Meteor Shower Defies Explanation - Space Daily Posted: 08 Dec 2010 03:09 PM PST Geminid Meteor Shower Defies Explanation by Dr. Tony Phillips Science@NASA Huntsville AL (SPX) Dec 09, 2010 The Geminid meteor shower, which peaks this year on Dec. 13th and 14th, is the most intense meteor shower of the year. It lasts for days, is rich in fireballs, and can be seen from almost any point on Earth. It's also NASA astronomer Bill Cooke's favorite meteor shower-but not for any of the reasons listed above. "The Geminids are my favorite," he explains, "because they defy explanation." Most meteor showers come from comets, which spew ample meteoroids for a night of 'shooting stars.' The Geminids are different. The parent is not a comet but a weird rocky object named 3200 Phaethon that sheds very little dusty debris-not nearly enough to explain the Geminids. "Of all the debris streams Earth passes through every year, the Geminids' is by far the most massive," says Cooke. "When we add up the amount of dust in the Geminid stream, it outweighs other streams by factors of 5 to 500." This makes the Geminids the 900-lb gorilla of meteor showers. Yet 3200 Phaethon is more of a 98-lb weakling. 3200 Phaethon was discovered in 1983 by NASA's IRAS satellite and promptly classified as an asteroid. What else could it be? It did not have a tail; its orbit intersected the main asteroid belt; and its colors strongly resembled that of other asteroids. Indeed, 3200 Phaethon resembles main belt asteroid Pallas so much, it might be a 5-kilometer chip off that 544 km block. "If 3200 Phaethon broke apart from asteroid Pallas, as some researchers believe, then Geminid meteoroids might be debris from the breakup," speculates Cooke. "But that doesn't agree with other things we know." Researchers have looked carefully at the orbits of Geminid meteoroids and concluded that they were ejected from 3200 Phaethon when Phaethon was close to the sun-not when it was out in the asteroid belt breaking up with Pallas. The eccentric orbit of 3200 Phaethon brings it well inside the orbit of Mercury every 1.4 years. The rocky body thus receives a regular blast of solar heating that might boil jets of dust into the Geminid stream. Could this be the answer? To test the hypothesis, researchers turned to NASA's twin STEREO spacecraft, which are designed to study solar activity. Coronagraphs onboard STEREO can detect sungrazing asteroids and comets, and in June 2009 they detected 3200 Phaethon only 15 solar diameters from the sun's surface. What happened next surprised UCLA planetary scientists David Jewitt and Jing Li, who analyzed the data. "3200 Phaethon unexpectedly brightened by a factor of two," they wrote. "The most likely explanation is that Phaethon ejected dust, perhaps in response to a break-down of surface rocks (through thermal fracture and decomposition cracking of hydrated minerals) in the intense heat of the Sun." Jewett and Li's "rock comet" hypothesis is compelling, but they point out a problem: The amount of dust 3200 Phaethon ejected during its 2009 sun-encounter added a mere 0.01% to the mass of the Geminid debris stream-not nearly enough to keep the stream replenished over time. Perhaps the rock comet was more active in the past ...? "We just don't know," says Cooke. "Every new thing we learn about the Geminids seems to deepen the mystery." This month Earth will pass through the Geminid debris stream, producing as many as 120 meteors per hour over dark-sky sites. The best time to look is probably between local midnight and sunrise on Tuesday, Dec. 14th, when the Moon is low and the constellation Gemini is high overhead, spitting bright Geminids across a sparkling starry sky. Bundle up, go outside, and savor the mystery. Share This Article With Planet Earth Related Links   Geminids Meteor Shower: 'Up All Night' With NASAHuntsville AL (SPX) Dec 06, 2010 Baby, it's cold outside - but you can still enjoy the best meteor shower of the year. The 2010 Geminid meteor shower promises to be lively, with realistic viewing rates of 50-80 meteors per hour and potential peaks reaching 120 meteors per hour. Anytime between Dec. 12-16 is a valid window for Geminid-watching, but the night of Dec. 13-14 is the anticipated peak. b>About the Chats br> /b> ... read more This entry passed through the Full-Text RSS service — if this is your content and you're reading it on someone else's site, please read our FAQ page at fivefilters.org/content-only/faq.php  This posting includes an audio/video/photo media file: Download Now |
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