Geminid fireball falling Earthward. (Source: NASA)
By Glenn A. Walsh
Reporting for SpaceWatchtower
The most intense meteor shower of the year, the Geminids, peaks this weekend: officially the peak is Sunday Morning, 2014 December 14 at 7:00 a.m. EST / 12:00 Coordinated Universal Time (UTC). So, Saturday night / Sunday morning and Sunday night / Monday morning would be the peak nights for viewing this year's Geminids.
Particularly in good years when Moon light does not hamper viewing, 80 to 120 meteors per hour can be seen. Although some people believe this meteor shower is intensifying, as 120 to 160 meteors have been seen, under optimal conditions, during this meteor shower in recent years. However, Moon light may be a problem this year, as just 51 minutes after the Geminid Meteor Shower peak, the Moon reaches the Last Quarter Phase, at 7:51 a.m. EST / 12:51 UTC. So, at this time of the month, the Moon rises around local Midnight or a little later in the early morning hours and sets in the early afternoon.
As always, the best viewing for a meteor shower is between local midnight and local dawn, when the Earth is rotating into the meteor shower. So, Moon light could interfere with viewing the smaller, dimmer meteoroids. However, it may not be as bad as last year, when a Full Moon was visible at the prime meteor shower viewing time. At least this year, only half of the Moon's surface visible from Earth will be illuminated by the Sun.
Due to the intensity of the Geminid Meteor Shower, some meteors can be seen a few nights before, and a few nights after, the meteor shower peak. Of course, the number of meteors that can be seen is less on nights other than the peak night(s).
Clear skies are always a must for meteor viewing, something not always available in late Autumn and early Winter skies. And, it is always best to get away from city lights, for the chance to see the dimmer meteors.
The Geminids are so named because most meteors appear to radiate from the Constellation Gemini the Twins (apparent meteor shower radiant), a constellation which becomes more prominent as the Winter season approaches in Earth's Northern Hemisphere. However, during any meteor shower, meteors can appear in any part of the sky at any time.
Telescopes and binoculars are of little use for finding meteors. Such optical devices restrict the field-of-view, thus that you could easily miss a lot of meteors, and the chance that you could observe a meteor with a telescope or binoculars is not very good. The best way to look for meteors is to lie down on the ground, in an area with an unobstructed view of most of the sky. Then, just keep scanning throughout the sky until you see a meteor.
While most meteor showers occur at a time when Earth's orbit coincides with a trail of debris from a comet, this is not the case for the Geminids. Amazingly, the most intense meteor shower of the year seems to come from a strange rocky object identified as Asteroid 3200 Phaethon, what some scientists call a "rock comet." Discovered by NASA's Infrared Astronomical Satellite (IRAS) in 1983, 3200 Phaethon has an eccentric orbit which brings it inside the orbit of Mercury every 1.4 years.
Even though this asteroid is regularly blasted with solar heat when it nears the Sun, scientists using NASA satellite data have concluded that the debris falling-off of the asteroid due to this heating could not have caused the amount of debris found in the debris trail which comprises the Geminid Meteor Shower. The amount of debris which scientists recorded as having fallen-off of this asteroid during a recent encounter with the Sun is too low.
Some researchers believe that 5-kilometer Phaethon may have been chipped-off of one of the largest asteroids in the Solar System, 2 Pallas (which is 544 kilometers in diameter). Could some past planetary collision, which caused Phaethon to break-off from Pallas, have caused the debris trail now known as the Geminid Meteor Shower? Scientists who have studied this possible scenario say no. They say that the Geminid meteoroids were created much closer to the Sun, not in the Asteroid Belt.
Hence, the explanation for the intensity of the Geminid Meteor Shower remains a mystery to scientists.
So, bundle-up this weekend and hope for clear skies to see the most intense meteor shower of the year, apparently caused by an astronomical anomaly.
However, if the sky is not clear in your neighborhood, or it is just too cold to lie on the ground looking for meteors, there are a few Internet web-casts that will show the Geminid Meteor Shower live:
Live Internet Web-Casts of the Geminid Meteor Shower ---
Slooh Community Observatory - Beginning Sat., Dec. 13 at 8:00 p.m. EST / Dec. 14, 1:00 UTC:
Link >>> http://live.slooh.com/
NASA Marshall Space Flight Center - Dec. 13 - 14, 11:00 p.m. to 3:00 a.m. EST / 4:00 to 8:00 UTC:
Link >>> http://www.ustream.tv/channel/nasa-msfc
Additionally, NASA will offer a live web-chat regarding the Geminid Meteor Shower at this link:
Link >>> http://www.nasa.gov/connect/chat/geminids_2014.html
The Virtual Telescope Project - Beginning Sat., Dec. 13 at 9:00 p.m. EST / Dec. 14, 2:00 UTC:
Link >>> http://www.virtualtelescope.eu/webtv/
More on the Geminid Meteor Shower ---
Link 1 >>> http://science.nasa.gov/science-news/science-at-nasa/2014/12dec_embers/
Link 2 >>> http://en.wikipedia.org/wiki/Geminids
More on Asteroid 3200 Phaethon: Link >>> http://en.wikipedia.org/wiki/3200_Phaethon
More on Asteroid or Minor Planet 2 Pallas: Link >>> http://en.wikipedia.org/wiki/2_Pallas
Source: Glenn A. Walsh, Reporting for SpaceWatchtower, a project of Friends of the Zeiss.
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