Perseid Meteor Shower

If you go outside at night this week, you might be able to see an annual event called the Perseid meteor shower.  It occurs yearly when the Earth passes through the comet Swift-Tuttle's debris trail.  This year, the shower will peak on the night of August 12-13, with the maximum being before dawn on August 13th.

The Perseids are called that because if you were to trace the origin of the meteors, they would appear to originate in the constellation Perseus.   This origination point is called the radiant, since the meteors seem to radiate out from this point.

When we experience meteor showers, the Earth passes through a debris trail left by comets or asteroids that have orbits that cross near our orbit around the Sun.  The debris is caught by the Earth and falls through the sky and what we see is the meteor.

There are a couple of definitions you should learn.

• Meteoroid - the actual object falling through the sky.  This can be as tiny as a dust particle or as big as an asteroid (which we really don't want)
• Meteor - this is actually what we see.  As the meteoroid falls through the atmosphere, friction causes the gas to heat up around the meteoroid and glows.
• Meteorite - if the meteoroid is large enough, it will not completely burn up as it falls and what is left when it hits the ground is a meteorite.

For your viewing pleasure, this week, Perseus is a little north of the Moon.