Geminids by Bob Yen / APOD.

Geminid Meteor Shower Peaks On December 13

Article Updated: 24 Dec , 2015

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Are you ready for one of the most hauntingly beautiful displays of celestial fireworks around? Then be on hand on the night of December 13 through the morning of December 14… Because the Geminids are coming to town!

Somewhere in England in the year 1862, Robert Greg and B.V. Marsh were busy sky watching. Across the sea, so was Professor Alex Twining in the United States. Both were doing independent studies on a little known meteor shower that looked like it was going to become an annual event and the count was on. In those years, the activity was prodigious, the meteor stream didn’t produce more than a few per hour, but as studies increases, so did the intensity. In fifteen years, astronomers realized they were on to a full blown meteoroid stream which was producing up to 14 per hour and increasing annually. By 1900 the rate had increased to over 20; and by the 1930s, up to 70 per hour. In the late 1990’s observers recorded an outstanding 110 per hour during a moonless night – but just what’s to blame for this sharp rise in activity?

Most meteor showers are historic – documented and recorded for hundreds of years – and we know them as originating with cometary debris. But when astronomers began looking for the Geminids’ parent comet, they found none. It wasn’t until October 11, 1983 that Simon Green and John K. Davies, using data from NASA’s Infrared Astronomical Satellite, detected an object (confirmed the next night by Charles Kowal) that matched the orbit of the Geminid meteoroid stream. But this wasn’t a comet… it was an asteroid. Originally designated as 1983 TB, but later renamed 3200 Phaethon, this apparently rocky solar system member has a highly elliptical orbit that places it within 0.15 AU of the Sun during every solar system tour. But asteroids can’t fragment like a comet – or can they? The original hypothesis placed Phaethon’s orbit within the asteroid belt. This means it may have collided with one or more asteroids, creating rocky debris.

While this theory sounded good, but the more we studied the more we realized the meteoroid “path” occurred when Phaethon neared the Sun. So now our asteroid is behaving like a comet, yet it doesn’t develop a tail. So what exactly is this “thing?” Well, we do know that 5.1 kilometer diameter Phaethon orbits like a comet, yet has the spectral signature of an asteroid. By studying photographs of the meteor showers, scientists have determined that the meteors are denser than cometary material, yet not as dense as asteroid fragments. This leads them to believe Phaethon is probably an extinct comet which has gathered a thick layer of interplanetary dust during its travels, yet retains the ice-like nucleus. We know that it doesn’t outgas so the mystery deepens even more.

In July 1996 the plot thickened even more when astronomers discovered something in the asteroid belt which may have affected 3200 Phaeton – another comet-like asteroid named Elst-Pizarro. On 1996 photographic plates, it displayed a tail, but no coma. Another Phaeton-like mystery? Possibly. Asteroid Elst-Pizarro pretty much makes its home in the main asteroid belt where asteroid-asteroid collisions are bound to happen and when Phaeton passes through every 17 months, the same could have happened to it. Until we are able to take physical samples of this “mystery,” we may never fully understand what Phaethon is, but we can fully appreciate the annual display it produces!

Thanks to the wide path of the stream, folks the world over get an opportunity to enjoy the show of the Geminids. The traditional peak time is as soon as the constellation of Gemini appears, around mid-evening. The radiant for the shower is near the bright star Castor – but meteors can originate from many points in the sky. From around 2 AM until dawn (when our local sky window is aimed directly into the stream) it is possible to see about one “shooting star” every 30 seconds. The most successful of observing nights are ones where you are comfortable, so be sure to use a reclining chair or pad on the ground while looking up… And dress warmly! Although the rising Moon will greatly interfere, please get away from light sources when possible – it will triple the amount of meteors you see.

Remember, even if you only spot just a few Geminids each one you see is a wonderful, unique mystery. They are tiny dust particles that measure no more than 10 microns across. What makes them special? Cometary fragments are about 0.3 gm/cc in density while Geminid particles measure more on the 2 to 3 gm/cc, end of the scale. More like rocks than ice. Enjoy the incredible and mysterious Geminids!

Geminid Photo by Bob Yen / APOD


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Marco Fitz
Guest
Marco Fitz
December 11, 2008 6:15 PM

will be visible in the southern hemisphere?

Richie
Guest
Richie
December 12, 2008 4:33 AM

From around 2 AM until dawn (when our local sky window is aimed directly into the stream)

Where is “local”? I am not “local” ! How many of your readers are “local”

Please Note this is the W.W.W. a large area !!!

Jeremy C
Guest
Jeremy C
December 12, 2008 4:55 AM

@ Richie: Its 2AM your time. Tammy knew that you were going to read the article and get upset and specially went to find out where you live and used that time so you would not be confused.

If you hadn’t ranted I would have used the less sarcastic response below.
2AM local time is the time at your location no matter where you are in the world. Indeed the www covers a large area which is why Tam uses the word local and not GMT or EST or PT etc. So in response to your question all Tammy’s readers are “Local”

bobby g
Guest
bobby g
December 12, 2008 1:23 PM

Aywen, if Orion’s Belt is high enough in the sky where you are in Borneo, look about 4 fists towards 8 O’Clock from the belt to start…

shona
Guest
shona
December 12, 2008 7:15 AM

was going ask if i will see it in scotland?

Marco Fitz
Guest
Marco Fitz
December 12, 2008 9:13 AM

thanks Tammy!

i can see it! smile

Aywen
Guest
Aywen
December 12, 2008 12:45 PM

I am in Borneo. I waited for so long just now, and I didnt see anything.. Is it already over?
Please reply.. anyone.. please..

Aywen
Guest
Aywen
December 12, 2008 12:45 PM

And please tell me what time will it be.. .Im really desperate to see it!!! REALLY REALLY…

Jon
Guest
Jon
December 12, 2008 4:45 PM

VERY nice Tammy! I was wondering if I can post your article on my observatory facebook page? I was going to write up an article myself, but yours is AWESOME! PLease let me know, I will include your name and credits with a link to this site if you want too.

Jon

Leah
Guest
Leah
December 12, 2008 9:36 PM

Just saw three beautiful meteors, within 15 minutes time. Green with long tails, one tail sparkly.

Jon
Guest
Jon
December 13, 2008 10:48 AM

Thank you Tammy! My group members will LOVE your article! Are you a member of facebook? If so, you can join our group! We are a group of people that do live broadcasts with our telescopes all over the country and a few worldwide! Anybody can watch our live broadcasts from their computers. Thanks again! ~jon

vna
Guest
vna
December 13, 2008 6:20 AM

so is the meteor shower over?

Santewath
Guest
Santewath
December 13, 2008 7:20 AM

How about in cambodia? What time can we see the meteor shower?

ruf
Guest
ruf
December 13, 2008 2:19 PM

Unfortunately we have nearly a full moon all night long ;(

Tiffany Bryant
Guest
Tiffany Bryant
December 13, 2008 8:48 PM

I just saw the largest meteor shoot underneath the full moon. The largest ever. (12/13/08 10pm) Hues of blue and green and moving very fast. I am in Atlanta Georgia and have a very clear night. I didn’t expect to see what my eyes took in. Amazing!

Bariman43
Member
Bariman43
December 13, 2008 10:21 PM

Aww! It’s cloudy over here! Darnit!! I was really hoping to see the Geminids this year…

j
Guest
j
December 13, 2008 10:53 PM

hI,….was just outside here, midnight on saturday the 13th…into the 14….about 25 miles nw of NYC….tons and tons…must have seen 15 within a half hour….gorgeous. NNW sky.

Good luck.

Carlos
Guest
Carlos
December 14, 2008 12:03 AM

Hey everybody, I’m in Guatemala it’s 1:00am CT, and I just saw half a dozen for about half an hour. its too cold and the moon is too bright I believe is right on Gemini isn’t it? But the sky couldn’t be clearer. I saw a couple of them very very bright at once, can you believe it?! This is amazing!

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