Perseid meteor shower is a big show

It’s the best meteor shower of the year for a lot of reasons. First, the Perseids are the heaviest, or least one of heaviest, meteor showers of the year. In the dark countryside you may see 60 to 100 meteors or “shooting stars” an hour. On top of that, the warm August nights make viewing the Perseids a true pleasure. As with any good show, though, you have to give up some sleep, but I guarantee it’ll be worth it.

The Perseid meteor shower has actually been going pretty good for the last week or so, but it peaks in its grand finale Sunday night, and especially Monday morning. It’s going to be a wonderful spectacle this year, because there won’t be any white-washing moonlight in the sky. That’s why it’s well worth it to make a trip away from city lights to view and enjoy the Perseids from the darkest sky you can.

The Perseid meteor shower is one of several dozen annual showers, but it’s certainly one of most prolific showers. Meteor showers occur when the Earth, in its orbit around the sun, plows into debris trails left by comets as they pass near the sun in their highly elongated orbits and release some of dust and rocks trapped in their frozen cores.

The ammunition for the Perseid meteor shower comes from comet Swift-Tuttle that swings by this part of the solar system every 133 years. It made its last pass in 1992. There are some heavier rocks in the debris trail, but mostly there’s just dust to gravel-sized pebbles that slam into Earth’s atmosphere at speeds of 40 miles a second or more.

When we see the streaks of light that make up the Perseids or any other meteors, some of light we see is certainly because of incineration due to air friction. Most of the light, though, is due to the debris disrupting the atoms and molecules of the column of air they’re shooting through. Electrons are temporarily bounced away from the nuclei of atoms, and when that happens, light is given off. That’s why you sometimes see the streaks take a few seconds to totally fade as the atmosphere gets its act back together.

You can stay up late Sunday night to see the Perseids, but you’re better off catching some Z’s and getting up early Monday morning. The best showing of any meteor shower is after midnight, because, as you can see on the diagram, that’s when you’re on the side of the Earth that’s plowing into the Swift-Tuttle comet debris. It’s like driving in the countryside on warm summer evening. You always get more smashed bugs on your front windshield than you do your rear windshield.

The best way to watch the Perseids is to lie back in a reclining lawn chair, or maybe on a quilt on the ground, and roll your eyes all around the skies. This meteor shower is called the Perseids, because the meteors seem to be originating from the constellation Perseus in the mid to high east-northeastern skies.

It would be a mistake though to restrict your gazing to northeast sky because you’re bound to miss many meteors. They will definitely be visible in all the predawn sky, but their tails will point back in the general direction of the constellation Perseus in the northeast. I think it’s a lot of fun to have a Perseid party with friends and family. The more eyes you have in the skies the more meteors you’ll see. In the dark moonless skies, especially in the countryside, you may see up to 100 meteors an hour. It’s worth losing some sleep over.

The Perseids are also known as St. Lawrence’s Tears in honor of the young Christian martyred by the Roman Emperor Valerian on Aug. 10th in 258. The poor guy was roasted alive on giant barbecue spit. After he met his demise and mourners were carrying his body away that night, streaks of light were falling like tears from the sky. The faithful believed back then that they were seeing celestial tears from heaven in sadness over the passing of Lawrence. In fact, they believe that the meteors show up again every year on the anniversary of his painful martyrdom.

Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and author of the new book “Washington Starwatch,” available at bookstores and on his Web site, www.lynchandthestars.com.