Radiant point for Geminid meteor shower
Print Me Email to FriendTonight is Wednesday, Dec 01 2010
The best time to observe the Geminid meteor shower may be in the late evening tonight, because there will be no moon to interfere and most of us find it easier to stay up late than get up early!
True meteor shower aficionados, however, also will want to observe tomorrow morning, December 14, in the hours before dawn.
Our chart today shows the radiant point for the Geminid meteor shower. The shower radiates from a point near the star Castor, one of the brightest stars in Gemini. This star represents a starry eye of a Gemini twin. Although the meteors can appear across a wide area of sky, you can trace their paths backwards to find that they all intersect at the radiant point.
The radiant represents a direction in the sky at which the Earth’s orbit intersects that of the object that causes the shower, which in this case is apparently an asteroid, 3200 Phaethon.
Geminids tend to be fast and bright. The exact number you can see varies with a number of factors, but 40 to 90 per hour at peak is a reasonable estimate.
One key to watching any meteor shower. Be sure to find a dark country sky!
Earth & Sky’s meteor guide for 2008
Here’s the help you need to see a meteor shower.
In the east after the sun sets, the order of our neiboring planets are Mars, Saturn, Venus before the sun dawns?
Isn’t Murcury traveling by the daytime?
Stratfort,
Actually, those planets are in the predawn sky, although Mars and Saturn rise before midnight. Right now, starting in the southeastern sky before sunrise are:
Venus — up to the right,
Saturn — even farther along the same line, and
Mars near the western horizon.
Currently, Mercury is very close to the sun in the sky. Since it is so close to the sun, Mercury never is seen in a truly dark sky, and spends most of its time in a daytime sky. Right now it is simply too close (apparently) to the sun to be seen at all.
Larry S.
whell it will be sweet if we se a really big one burn up into our hemisfeere
What is the best time in the evening, on Dec. 13 to see the shower?? I live in NC.
Candace, the general answer is “as late as you can.” The predicted peak is not until after dawn on the 14th (Friday), but obviously you will see nothing after the sun comes up. Fortunately, the radiant point is well up in the eastern sky by late evening, so you likely will be able to see some on Thursday night (as well as perhaps on Friday evening). However, the radiant is at its highest at about 2 or 3 a.m., so that stretch between midnight and Friday morning is best. (The radiant is not far from very bright Mars.)
Observing as close to the time of peak is important, but two other factors come into play that make the post-midnight best. For one thing, meteors are generally best after midnight due to the geometry or the orbits. Second, generally speaking, the higher the radiant, the better for meteors because their light is less attenuated by the atmosphere. (Observing may be a bit more difficult simply becuase you will need to look high overhead rather than toward the horizon — although the meteors are spread over a rather wide swath of sky.) So you may have a good chance late on Thursday evening, but I suspect the best will be from maybe 3 a.m. to dawn on Friday. (Before dawn on Friday the radiant will be high in the western sky.)
Good luck.
Larry Sessions
Denver
Hi Folks,
Just wanted to report that tonight (Wednesday, 12 December)between 8-10pm EST we (my dog and I) saw a number of meteors, probably 5 all told, in Stoneham, MA, about seven miles north of Boston. A beautiful clear night, and Mars leading on the twins! By the way, it’s Castor, not Caster, as it’s spelled here. We had to go out this evening, as tomorrow night will be stormy. Happy Geminiad watching!
Hey, BiscuitBoy! Sounds like you had some good observing. And you’re correct on the spelling. I should have caught that but it flew right past me!
Larry Sessions
Denver
Okay, if I plan to observe between 3 and 4 am. where should I look? North, east, etc.? I’m really tryin to set up a cute little surprise for my boyfriend. Please comment back asap!
Candace,
At that time, Gemini and the radiant of the shower will be high overhead, so basically that is where you want to look. Earlier to the east, later (just before) dawn a bit more to the west. But at 3-4 a.m. it is high overhead. That basically means lying flat on the ground. I don’t know where you live, but that would not be great here in Denver, where we have snow. You could use a cot or a chaise longue.
You do not want to stare at a particular spot in the sky, but to scan a large area generally centered on Gemini. In fact there may be only a few meteors that appear actually in Gemini. However, if you traced the trajectories of other Geminids back, they would cross in Gemini (called the “radiant”). At 3-4 a.m., the meteors could really appear anywhere in the sky, but by facing the general direction of the radiant you have a better chance of catching the most. You also need a good, unobstructed view of as much of the sky as possible. Stay away from lights and if you use a flashlight, put red cellophane over the lens if you can, and do not look directly into the flashlight or any other light. It is amazing how quickly that can ruin your night vision and make it hard to see faint meteors!
You seem to be covered here, but I always tell people to observe safely and preferably never by yourself.
Good luck.
Larry S.
Denver
Didn’t your website used to have a link where you could enter your location and it would provide a snapshot of the current stars and planets in the sky? The viewer could rotate right or left and enter different time frames for your location?
Thanks,
Tim
Tim, not to my knowledge — but something similar is in the works. In the meantime, you might want to try out the sky feature in Google Earth.
Larry S.