Every year, right in the middle of August, my cousins and I drag all our sleeping bags and
pillows up to their roof and wait for the sky event that goes highly unnoticed every year: the Perseid meteor shower. We sit and stare, and it’s only a short wait until we see the tiny white streaks across the sky. They come every few minutes and sometimes you can see two at a time! Every year, right in the middle of August, you can see them.
If you know about space, it’s huge. Endless. Something we can’t even comprehend. What
are the odds that so many meteors would somehow land in our night sky? And why so
consistent?
First of all, what is a shooting star actually? Shooting stars are not stars at all. They are tiny particles of ice and rock, called meteoroids that enter our atmosphere. As they do, their great speed causes them to vaporize in our atmosphere. As they vaporize, their remnants glow brightly, leaving trails behind them before they disappear in the sky. When they enter
our atmosphere, they become meteors, and if and when they reach Earth they are called
meteorites. But since the likelihood of meteors making it all the way to Earth’s surface is low, we get to watch this surreal natural firework show each summer without any worries.
If you’re wondering how scientists can measure something that seems so random and
unpredictable as space rocks’ path into our atmosphere, here’s your answer. Meteors that we see during meteor showers are the remnants of comets, large clumps of ice and rock that range from a mile in size to tens of miles. When they approach the Sun, comets often eject smaller icy and rock particles and leave trails of debris that orbit the Sun. Periodically, the comet Swift-Tuttle, has ejected material and left trails of debris, which have dispersed along the comet’s orbit. These debris trails are responsible for the Perseid meteors. The debris streams are moving; they orbit the sun in about 133 years, the same orbital period as their parent, Comet Swift-Tuttle. Each August, the Earth in its orbit of the Sun moves through these debris streams. Consequently, every year around August 12, debris from Comet Swift-Tuttle enters our atmosphere, and we see many Perseid meteors. If you’re lucky, you could see up to 100 meteors per hour.
I invite you to get out there this summer and look out for them! It’s the most peaceful yet
enticing light show and knowing the science behind it is absolutely intriguing.
Thank you for listening to Western Slope Skies, produced by the Black Canyon
Astronomical Society and KVNF Community Radio. This feature was written and recorded by
Xennia Perry, an astronomy student of Dr. Catherine Whiting at Colorado Mesa University.
