Perseid Meteor Shower To Reach Its Peak Tonight

Transcript

MELISSA BLOCK, HOST:

Let's get ready for the sky to explode - in a good way. With any luck, and a reclining lawn chair, we'll be able to see that summer show called the Perseid meteor shower tonight - maybe even a fireball or two. That's a special subsection of meteor showers, and we'll ask our next guest about that and all things shooting stars. Kelly Beatty, with Sky & Telescope magazine, joins me now. Kelly, welcome back to the program.

KELLY BEATTY: Hey, hi, Melissa.

BLOCK: And the Perseid meteor shower comes around every year, but this year is supposed to be an especially great one. Why is that?

BEATTY: It certainly is. First, there's no moon in the sky. We're approaching new moon, and so there won't be that wash of glow in the sky that will wash out the fainter meteors. And the second thing is that the Perseids have a peak that will occur at about 4 a.m. Eastern time - that's 1 a.m. on the West Coast. That means that overnight we will see the most meteors possible. It couldn't be better for North Americans.

BLOCK: Now, we do talk about this with you pretty often, Kelly, 'cause it does come around every year, but go ahead and remind us again. What causes these gorgeous streaks of light across the sky?

BEATTY: We're talking about little particles that are entering the atmosphere about 37 miles a second. And when they do that they superheat the air in that thin, upper atmosphere to glowing white-hot, and that's what we see as a meteor. The particles come from a comet called Swift-Tuttle. It has scattered over time little particles all along its orbit. And every mid-August the Earth plows through that little river of rubble and we get a peppering of meteors in our atmosphere that lasts a few days.

BLOCK: Now, Kelly, I mentioned fireballs. That sounds exciting.

BEATTY: Fireballs are amazing. Most meteors are just little flicks of light that go ooh and ah and then they're gone. But a fireball can leave a long-lasting glow in the sky along their path. Sometimes we can see colors associated with them. And the Perseids are pretty well-known for fireballs, so everyone should be on alert for something that's really dramatic tonight or any of the nights coming up.

BLOCK: And what causes the fireball? What makes that extra bright?

BEATTY: Well, it's a little bit bigger particle. Most of these meteors are no bigger than the size of, say, sand grains. But every now and then you get something the size of a pea or maybe even a walnut. And when that slams into the atmosphere at 37 miles a second, it creates a tremendously bright flash.

BLOCK: You know, I'm amazed to hear you say that, that the regular meteors that we're seeing, they're just the size of a grain of sand and the fireball, just the size of a pea.

BEATTY: Yeah, I often use Grape-nuts cereal to kind of demonstrate what these are like, you know? They're little fractal particles, probably pretty close to what a typical meteor particle looks like before it slams into the atmosphere.

BLOCK: And for those of us who have the bad luck to live in cities, Kelly, is there any hope of seeing anything? Is there any reason to stay up late tonight?

BEATTY: There is always hope, Melissa.

BLOCK: (Laughter).

BEATTY: (Laughter) The best thing to do is to make sure that you're shielded from any lights locally to you - streetlights - turn off your porch light. Go outside and give yourself at least 10 or 15 minutes for your eyes to adjust to the darkness. And you will see the bright ones. You might not see one per minute, but you'll definitely see some.

BLOCK: Kelly Beatty, thanks for talking with us, and have fun tonight.

BEATTY: Oh, thanks, Melissa, clear skies to you.

BLOCK: Kelly Beatty is senior contributing editor with Sky & Telescope magazine. And you'll find lots of viewing tips on their website, skyandtelescope.com. Transcript provided by NPR, Copyright NPR.