麻豆国产

Once a year in August, the night sky is graced by the glittery display of the Perseid meteor shower. Robert Quimby, 麻豆国产 professor of astronomy and director of Mount Laguna Observatory, shares that this summer will be an exceptional one for witnessing this cosmic event.

In this Q&A, Quimby explains the best times to see the Perseids, what is needed for a successful viewing experience and the science behind the shower.

What are the Perseids?

The Perseid meteor shower is an annual event where the Earth passes through the orbit of the comet Swift-Tuttle. Debris that's being spewed off of the comet rains down on the Earth. Those little pieces of comet dust enter the Earth's atmosphere at very high speed, heat up, strip off their outer layers and make meteors we see once a year. The peak happens around the night of Aug. 12 each year.

When is the best time to view the Perseids? 

If you want to see the most meteors, it helps to go around the peak. To see all the faint meteors, you want the sky to be dark, so an hour or so after sunset up until about an hour or so before sunrise. Before sunrise is the best time to observe because that's when the side of the Earth that you're on is moving directly into the stream, so you'll see the most meteors.

Sometimes people think meteor showers are one-night events. They're actually not. As I said, meteor showers are when the Earth passes through a stream of comet debris, and that can take weeks. There's always background meteors, but around a day or two before the peak to a day or two after the peak, most of what you see will be Perseid meteors. So if it's cloudy the night of Aug. 12, try either Aug. 11 or 13. 

Where should people look in the sky for the Perseids?

The best place to look is toward the Perseus constellation, near the north, a little bit over from the constellation Cassiopeia, which makes this nice 鈥淲鈥� on the sky. But there's really no wrong place to look other than down. 

How visible will the Perseids be in San Diego?

The key to any meteor shower is dark skies. If you're in the city, you're only going to be able to see the brightest meteors and there's not many that are bright enough to see above the lights of San Diego. If you get out somewhere where it's darker, East County for example, where the mountains or the deserts are, you can see a good number 鈥� a few per hour, probably.

As far as the moon goes, this is a great year. The moon is bright and it makes the sky glow just like the sun does. So, when the moon is up, it's hard to see faint meteors. But, fortunately, around the peak of the Perseids this year, the moon will be down and it's going to let us see some of the fainter meteors that we would otherwise miss. So this is a great year to see the Perseids. 

Do you need any special equipment to watch the Perseids?

No. The best thing you can do to look at a meteor shower is just use your eyes. The meteors are going to be darting around the sky, covering large areas of the sky very quickly, and you're not going to have time to point your telescope or binoculars here or there. So, just lie down in a nice, comfortable setting, look up, and enjoy the show.

How do the Perseids compare to other meteor showers?

The Perseids are one of the best ones because it鈥檚 during the summer, and in San Diego, it's pretty nice at night, so it makes for a good viewing experience. The Geminids is a really great meteor shower with a lot of meteors but that is in December, so it's going to be cold outside. 

The quality of meteors varies from shower to shower. Some have lots of little ones and very few big ones. The Perseids has a higher percentage of brighter meteors than some other meteor showers. So when you do see a Perseid meteor, more often than not, it's going to be a bright one.

What鈥檚 the difference between a meteor and a shooting star?

Meteors are pieces of debris from asteroids and comets that glow and pass through the Earth's atmosphere. A long time ago, people didn't know what meteors were. They look like a star that suddenly flew across the sky, so they called them shooting stars. You can call them shooting stars, it's the same thing. 

We call the little rocks in space before they enter the Earth's atmosphere meteoroids. A few will actually go all the way through Earth's atmosphere and land on the Earth's surface. We call those meteorites, because it's a rock that came from a meteor. So you got meteoroids, turns into a meteor, turns into a meteorite.