One of the Year's Best Meteor Showers Is Almost here

One of the year's best celestial events is almost here. The Perseid meteor shower will peak on the nights of August 12 and 13, and this year should provide excellent viewing thanks to a thin crescent Moon that won't wash out the display. Under dark skies, observers may see up to one hundred meteors per hour, including the occasional brilliant fireball.

One of those brilliant streaks may be created by a particle no larger than a grain of sand.

That tiny speck may have spent billions of years frozen inside Comet Swift-Tuttle, an icy relic left over from the birth of our solar system about 4.5 billion years ago.

The best part is that you don't need a telescope. If the weather cooperates, all you have to do is look up.

Astronomers believe Swift-Tuttle originated in the distant Oort Cloud, a vast reservoir of icy objects in the outer reaches of our solar system. The Oort Cloud begins roughly 50 times farther from the Sun than Pluto, making it one of the most remote regions under the Sun's gravitational influence. Long ago, gravity nudged the comet toward the inner solar system, placing it on the 133-year orbit it follows today.

Every time Swift-Tuttle swings close to the Sun, its icy surface warms and releases tiny grains of dust and bits of rock. Those particles continue orbiting the Sun along nearly the same path as the comet. Over thousands of years, they have formed a broad stream of debris stretching billions of miles through space.

Every August, Earth's orbit crosses that ancient trail. Although Comet Swift-Tuttle itself is usually far away, our planet passes through the debris it has left behind over countless journeys around the Sun. As millions of these tiny particles plunge into Earth's atmosphere at more than 130,000 miles per hour, they create the Perseid meteor shower.

So why does something no larger than a grain of sand create such a spectacular streak of light?

The answer is speed.

As a tiny comet fragment slams into Earth's atmosphere, it compresses the air in front of it so violently that the air becomes superheated and glows. The brilliant streak you see isn't the grain of dust itself. It's a trail of glowing, ionized air stretching for miles across the upper atmosphere before fading away.

You don't have to stay up until the middle of the night to enjoy the show. Meteors can appear anytime after darkness falls, especially after 10 p.m. The display gradually builds through the night, with the greatest activity occurring between 1 a.m. and dawn. By then, your part of Earth has rotated toward the direction our planet is traveling, allowing the atmosphere to sweep up more particles from the comet's debris stream.

For the best view, find a dark location away from city lights and give your eyes about 20 to 30 minutes to adjust to the darkness. Face generally east or northeast, but don't stare at one spot. Meteors can appear almost anywhere in the sky, so your eyes are your best viewing tool.

Planning to watch the Perseids? Click here for the best viewing times, where to look, and a few tips to help you catch more meteors.