Look up tonight and you’ll see streaks of light headed your way. The annual Perseid meteor shower has arrived, and if the skies are clear and light pollution low, you are in for quite a treat: This is easily the best meteor shower of the year. Those who stay up late (or wake really early) are virtually guaranteed to see something.
FROM SLAYER OF MEDUSA TO COMETARY DUST
The Perseids are the result of a debris field left by the comet Swift-Tuttle. This is a Halley-type comet that orbits the Sun every 133 years. (Its highly eccentric orbit takes it far beyond Pluto in the meantime.) As the comet travels across the solar system, it leaves behind a trail of dust and sand-sized particles that, over the course of centuries and millennia, becomes an increasingly dense field. When the Earth's orbital path crosses this debris, the speed and force of our planet colliding into the comet's phantom particles vaporizes them. A distinctive "shooting star" is the result of energy released by a speck of cometary dust colliding with the atmosphere of a 3.7-octillion-mile celestial object—that would be Earth—moving at 67,000 miles per hour.
The Perseids get their name from the constellation from which they seem to originate: Perseus. Don’t limit yourself to staring at the celestial slayer of Medusa, however. (Though bonus points if you can actually find it.) Meteors will appear across the night sky. The shower was first formally "discovered" in 1835 by astronomer Adolphe Quételet, though it has been observed for millennia. Meteors near the shower’s peak are sometimes called the "tears of St. Lawrence," coinciding with the feast day of St. Lawrence of Rome.
KEEP AN EYE OUT FOR FIREBALLS
If you are in an area of low light pollution—that is, any remote area away from a city—you will be able to see between 30 and 40 meteors per hour this weekend. Believe it or not, that makes this a bad year for the Perseids shower, down from a possible 150 per hour. Many meteors will be obscured by the big bright Moon still riding high after reaching a full phase earlier this week.
To best experience a meteor shower, NASA recommends you dress for the lower temperatures that come at night and give your eyes a good 30 minutes to adjust to the darkness. Take a blanket outside, lay back, and take in the sky. Be on the lookout for fireballs, which are particularly bright meteors. (You'll know one when you see it.)
The best time to see the Perseids shower is between midnight and dawn on Saturday. If you miss the Perseids early Saturday morning due to bad weather (or just sleeping in), you can try again at the same time each early morning well into next week. If being outside just isn’t your thing, but astronomy is, you can also view the meteor shower online at Slooh, beginning at 8:00 p.m. EDT on Saturday. The Perseids are the perfect warmup for the main event later this month: a total solar eclipse over North America on August 21.