Brace yourselves to witness the most intense meteor shower next week as the Geminid shower, which peaks this year on December 13 and 14, promises to be the best celestial event of the year. The shower, which lasts for days, is rich in fireballs, and can be seen from almost any point on Earth.
The Geminids are a meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid, making Geminids the only meteor shower not originating from a passing comet.
The meteors in this shower originate from the constellation Gemini, from where the shower also gets its name. Meteor showers are generally named after the constellation they come from or radiate. The term radiant, therefore, refers to the circle in the sky where the meteors would appear to come from. However, Germinid meteors can appear almost anywhere in the night sky, and often appear yellowish in color.
The meteors from this shower are slow moving and can be seen in December, usually peaking around the 13th - 14th of the month, with the date of highest intensity being the morning of the 14th.
The shower is thought to be intensifying every year and recent showers have seen 120-160 meteors per hour under optimal conditions, generally around 2 am to 3 am GMT.
Geminids were first observed only 150 years ago, much more recently than other showers such as the Perseids and Leonids
The Geminids are my favorite, because they defy explanation, NASA astronomer Bill Cooke said in a statement.
Most meteor showers come from comets, which spew ample meteoroids for a night of 'shooting stars.' But, the Geminids are different. The parent is not a comet but a weird rocky object named 3200 Phaethon that sheds very little dusty debris.
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 pound gorilla of meteor showers, while on the other hand 3200 Phaethon is more of a 98 pound weakling.
3200 Phaethon, which is only 15 solar diameters from the sun's surface, was discovered in 1983 by NASA's IRAS satellite and promptly classified as an asteroid. Meanwhile, 3200 Phaethon bears a close resemblance to the main belt asteroid Pallas.
If 3200 Phaethon broke apart from asteroid Pallas, as some researchers believe, then Geminid meteoroids might be debris from the breakup, says Cooke. But that doesn't agree with other things we know.
Researchers have concluded that Geminid meteoroids 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.
UCLA planetary scientists David Jewitt and Jing Li said 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.
However, the scientists said that though the rock comet hypothesis is compelling, the amount of dust 3200 Phaethon ejected during its 2009 sun-encounter added a mere 0.01 percent to the mass of the Geminid debris stream-not nearly enough to keep the stream replenished over time, indicating that the rock comet could have been 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. Scientists say the best time to look is probably between local midnight and sunrise on Tuesday, December 14, when the Moon is low and the constellation Gemini is high overhead, spitting bright Geminids across a sparkling starry sky.
The meteors travel at medium speed in relation to other showers, at about 22 miles per second, making them fairly easy to spot. The Geminids are now considered by many to be the most consistent and active annual shower.
In 2005, viewing of the shower was restricted due to a full moon washing out the fainter meteors. The 2006 shower had a less full moon, however the 2007 shower was a new moon, with the best viewing position being in the southern hemisphere, with Australia, New Zealand and Chile being noted spectacle locales. In 2008, the Geminids coincided with a full moon. In 2009, the peak date occurred two days before a new moon