Geminid Meteor Shower 2011

The Geminids peak the nights of December 13th and 14th this year, one of the better meteor showers of the year. Unfortunately for 2011, most of the Geminids will be nearly invisible due to the very bright Moon that dominates the late night and early morning sky, when the Geminids are at their best.

The effect of a bright Moon on a meteor shower was vividly illustrated to me during the Total Lunar Eclipse a few days ago. I was at Ocean Beach on the west coast of San Francisco for the eclipse in the early morning hours. Facing west, Gemini was directly in front of us, dominating the western sky. As the brightness of the Moon faded, we began to notice meteors -- we were seeing some very early Geminid meteors, facing the radiant directly. I was very surprised at the stark contrast in meteor visibility from Full Moon before the eclipse started, to an ever-increasing amount of meteors over a very short period of time as the Moon, in effect, when through all of its phases in about 60 minutes. It reaffirms for me the huge difference a moonlit night makes when watching a meteor shower.

Although the meteors will be diminished for the Geminid Meteor Shower in 2011, I'll still take a look, since a big shower like this has plenty of bright meteors that pierce the night despite moonlight. If you want to read more about the Geminids, check out this interesting article about the Geminids radiant, from Earth Sky, from the LA Times, or this one from NASA Science News.

Image courtesy EarthSky.

Geminid Meteor Shower 2010

One of the best Meteor Showers of the year takes place in favorable conditions on Monday night December 13th into the morning hours of December 14th. The shower is called the Geminids, named after the constellation Gemini. The Geminids appear to originate from the constellation Gemini which rises shortly after sunset and is high in the sky around midnight. This point in the sky is called the radiant, and if you trace the paths of the meteors backwards, they will all converge in this point.

Meteor showers generally get better late into the night because the Earth is rotated in the direction of its orbit around the Sun and consequently we encounter a higher number of meteors, on average. This is certainly true for the Geminids, and in dark conditions after midnight you might see 1 or even 2 meteors a minute. Being winter, you have to really prepare for this by dressing extremely well for your local conditions. I plan to get up early and look for Geminids in the early morning hours of Tuesday 14th, since the Sun does not impact the viewing until after 6:00 am.

This year is particularly favorable for the Geminids because the Moon is at First Quarter and will not be a factor after midnight. Stay warm and enjoy the show!

Image courtesy of Earth Sky.

KFOG Podcast - December 3, 2010

Today on the KFOG Morning Show Podcast with Irish Greg, we talked about the discovery of new stars in the galaxy, alien life forms right here on Earth, the upcoming Geminids Meteor Shower on December 13-14, the upcoming Total Lunar Eclipse on December 20-21, and Holiday Shopping including a special 10% discount on anything at Scope City in San Francisco (my favorite place to shop) if you mention KFOG or The Urban Astronomer. Click here to listen. And take advantage of the 10% offer while it lasts!

KFOG Podcast - October 26, 2010

Today's Urban Astronomer talk with Irish Greg of the KFOG Morning Show features the North Star, Meteor Showers in November and December, some early shopping tips for the holidays, cool iPhone Apps, Jupiter and more. It's always a treat to talk with KFOG and share some astronomy tips with the listeners. Click here to listen.

Geminid Meteor Shower 2009

One of the finest meteor showers of the year is the Geminids, so named because the meteors appear to emanate from the zodiac constellation Gemini. The shower peaks this year on Sunday evening December 13^th and for us on the west coast of the United States, we will be well placed for the peak of the shower at 9:00 pm. Given that there won’t be any moonlight for this meteor shower, conditions are ideal for a good shower that can produce up to 120 meteors per hour in very dark conditions. For those of us who live in urban areas such as San Francisco, we will see considerably fewer meteors. Nonetheless, if you can get yourself away from streetlights, houselights and allow some time to adapt to the dark, you will see some Geminids.

Meteor showers that occur at the same time every year are usually caused by some kind of debris trail that the Earth intersects, showering the upper atmosphere with fine particles in an unusually intense period of time. Based on the way in which the Earth intersects the tiny bits of rock and dust, the meteors will all appear to originate in a single point in the sky, a point known as the "radiant." The Geminid meteor shower appears to originate in the constellation Gemini and as this constellation rises shortly after sunset, this particular meteor shower appears strong all night long, as Gemini treks across the sky from the east nearly directly overhead and then dropping into the west.

NASA has a great website talking about the origins of the Geminids, and Sky & Telescope Magazine has a very helpful article (written by Tony Flanders, an astronomer I've come to know personally) that is full of good tips for seeing the Geminids.

The weather outlook is always a challenge for December, and if the skies are clear they are most assuredly accompanied by a cold evening, so dress extra-warmly for the Geminids and enjoy.

Perseid Meteor Shower 2009

It's August and that means its time for the annual Perseid Meteor Shower, this year reaching its peak on the evening and through the morning of August 11-12. Meteors are visible just about any night of the year, but throughout the year there are periods of intense activity in the sky ("meteor showers") because the Earth travels through a point in its orbit where there is a higher amount of space dust, rocks and other particles that enter the atmosphere at tens of thousands of miles per hour and burn up, creating bright streaks across the sky.

The Perseid Meteor Shower is going to be harder to see in 2009 because of the bright Moon that rises at 10:40 pm in San Francisco. For the city dweller, however, the shower is not much worse because of the bright Moon, as our city lights obscure many meteors anyhow. So the best you can do is simply enjoy the shower the evening of August 11th from wherever you are in the city. Pick a darkened comfortable spot. Lay back on a blanket and point your feet to toward the north-east and look around the sky. As the evening wears on, the origination point ("radiant") of the meteor shower rises in the north-east. This area is near the constellations Perseus and Cassiopeia as shown in the illustration to the right.

This year there will be a possible jump in the number of meteors as the Earth passes through a denser-than-usual filament of dust from the remnants of comet Swift-Tuttle. That will happen around 1:00 am pacific time on the 12th, so if you are up late you might just see a more intense period of meteor activity. Throughout the entire evening, the Moon will remain the one bright light everyone cannot escape, so when it rises just point your gaze in another direction and keep your eyes on the sky. And stay warm!

If you want to see a good meteor shower this year that won't have moonlight in the way, look ahead to December 14th when the Geminids will peak at an even higher rate than the Perseids. However it will be considerably cooler and the weather is less predictable at that time.