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Geminid
Meteor Shower
December
12/13
What
is a meteor?
A
meteor is a shooting star, space dust about the size of a grain of sand.
The dust hits the earth’s atmosphere and burns up in a blaze of light.
Where does space dust come from? Comets and asteroids pass through our
solar system. These objects leave dust behind them. When earth crosses
through these dust clouds we see a meteor shower.
Geminids
There
are two reliable meteor showers each year. These are the Perseids and the Geminids. Most meteor showers are left over debris from
comets. The Geminids, however, are from an asteroid named 3200 Phaethon.
The
Geminid meteor shower usually sees about 80 meteors per hour at its ZHR,
Zenith Hourly Rate. The Zenith Hourly Rate is the time when the
constellation is at its highest point in the sky when we cross through
the thickest part of the dust cloud left by Phaethon.
When
and Where
The
Geminids radiate from the constellation Gemini. This
constellation rises in the east and travels across the sky towards the
west. On December 12th and 13th we will see
the first peak and on 13th & 14th we will see the second, larger peak.
More at spaceweather.com
(direct
link to graphic on the peaks). The Geminid meteor shower is different than other meteor showers in that
it has a good show before midnight, and is even better after that
time.
Meteor
Counts
Taking
a meteor count is fun and easy. There are many different ways that
people take meteor counts. You will need a timer, paper, pencil/pen,
light (preferably red) and warm clothes.
Remember
to dress warm! Those winter nights can be quite chilly. You might also
consider bringing a lawn chair to lean back in to view the sky. Some
prefer to lay down a blanket and watch the show. Some hot chocolate is
always helpful for the chilly nights:)
Astronomers use a red light to observe stars and astronomical events.
Ones eyes must adjust to the lack of light at night. A white light is
harsher on the eyes and it takes longer for the eyes to re-adjust to the
darkness than it does if one is using a red light. Making a red light is
easy. All you need is some red plastic to cover the end of the
flashlight and you have instant red light:)
Set
your timer to go off as often as you wish. I’ve used three minute intervals for
the Geminids for several years now. Fellow HAS, Houston Astronomical
Society, members have used one or five minute intervals. It is all up to
you. Write the time you start observing. Every time you see a meteor
then make a tally mark. When the timer goes off then block off the first
time period. Write down the next starting time and begin your timer
again. You can do the meteor counts for as long as you like.
It is really fun and interesting to take counts with someone else.
Remember your meteor counts are just meteors that you see, not meteors
that your friend sees. At the end of the session count up your tally
marks and place them in a graph. Compare your numbers to your friend to
see who saw more.
Reflection
Was
there a pattern in how many meteors were seen? Generally meteor showers
come in waves. An observer might see several within a few minutes and
then none for a while. Taking meteor counts and creating a graph will
help you see the frequency of meteors observed.
Did
they all happen in the same part of the sky? The Geminids seem to come
from an area in Gemini, hence the name of the meteor shower. It is best
not to look directly at the constellation, but off to theh sides of it. Although the Geminids will
be all over the sky, to be a true Geminid you should be able to trace
the meteor back to the constellation Gemini. There are some meteors that
will originate from different parts of the sky, these are sporadic
meteors, not belonging to any meteor shower.
What
colors were seen? Meteors come in many different colors. The Leonids
tend to be green in color. The Geminids tend to be yellow, but come in
many colors. Some meteors also leave trails that hang in the air for
several seconds. These are more frequent in other meteor showers, but
not uncommon in the Geminids.
Did
some meteors change direction in flight? I have seen the Leonid and
Geminid meteor showers for several years. During this time, myself and
fellow HAS members have seen a few Geminids that change direction in
mid-flight.
These
are all very important questions to be asked of any meteor shower and
help the observer understand and appreciate it more.
Example
of Meteor Counts
I
have completed two years of meteor counts on the Geminids. In addition
to the meteor counts I like to take pictures and write a brief
observation of the event, listing people who were with me and conditions
during the counting.
You
are welcome to view my Geminid meteor counts for 2002 and 2003 at my
website at http://www.weatherfriend.com/astronomy/meteor/geminids/geminid_main.htm
I
would love to hear of your observations and counts. If you have any
questions please send them my way.
Thank
you all for reading.
Christie
Ponder.....wxstar3@hotmail.com
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