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Perseid Meteor Shower
August 11 & 12, 2004
One of the most watched meteor
showers of the year is coming up around mid
August. The Perseid meteor shower is often an
impressive display, with up to a hundred meteors
an hour seen. Meteor showers are the result of
the Earth moving through a "debris stream" left
behind by comets. (As comets orbit the Sun, they
leave behind an elliptical dirty path). Originating near the constellation
"Perseus", the Perseid meteors are part of the debris
stream of Comet Swift-Tuttle. The comet,
discovered in 1862, has an orbital period of
about 135 years and was last seen in the 1990's.
It will not be visible in the sky again during our lifetimes.
When you observe the Perseids (or any meteor display) don't stare directly at the radiant, as the meteors can appear anywhere in the sky. This is why I usually point my cameras well away from the radiant when I attempt meteor photography.
Instead of staring at one place, keep scanning the entire sky. You'll see meteors that you would have missed by staring at Perseus. This is especially important because Perseids are such quick, short-lived meteors. And now you don't need to know a single constellation to enjoy the shower!
Thanks and keep up the good work!
Dan Glomski
Director, J.M. McDonald Planetarium
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| Although a few
meteors will grace our skies between now and the
last week of August, the peak will occur just
before mid month. In North America, the peak of the shower
will be during the pre-dawn hours (between 2 and
4 am) on August 12th.
Lie on your back, look up at the constellation
Perseus (northeast portion of the sky), and
watch the show. Forecasters predict that this
year's event should be pretty good. |
Comet Swift-Tuttle |
Also, on the evening of the 11th, longer meteors may
be seen just after sunset. These meteors are
called "Earthgrazers", as they seemingly emerge
from the horizon and streak through the
atmosphere. Although not many are usually
seen, they are slower and more colorful than the
normal Perseid meteors.Another interesting
event should occur with this year's Perseid
peak. An extra surge of meteors is expected on
August 11th, due to a filament of space dust
that is drifting across Earth's orbit. This
filament is believed to have boiled off the
comet during its visit during the American Civil
War (1862). However, this peak will occur around
3:00 pm MDT, so Europe and Asia will have the
best viewing.
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Unlike last year,
when the moon was nearly Full, this year's
Perseid peak will occur with a moon approaching
its New phase. This darker sky will allow better
viewing conditions. The meteor radiant (where
the meteors originate) will be about half way up
the sky, above the low-elevation moon.
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In Grand Island on
August 12, 2004: |
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Average High: 86° /
Average Low: 64° |
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Sunrise: 6:40 am / Sunset: 8:36 pm |
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Moonrise: 2:59 am /
Moonset: 7:04 pm |
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(Courtesy of NASA)
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