Date: November 13, 2009

Title: Thrilling Meteors Streak the Sky

Podcaster: Gregg Paris

Organization: San Diego Astronomy Association

Description: The Leonid and other meteor showers: What and when to see, where to look, where to go for better viewing, what to take with you. Their causes and sources. I saw 100,000 meteors one night!

Bio: Gregg Paris has been an amateur astronomer and telescope builder since 1958. He’s staffed planetaria in Houston and San Diego, worked as an optics engineer for scanning spectrophotometers and infrared lasers, been a community college instructor in CAD, and special effects designer for Disney parks, all with a B.A. in Economics.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by the American Astronomical Society, the major organization for professional astronomers in North America, whose members remind everyone that One Sky Connects Us All. Find out more or join the AAS at aas.org.

Transcript:

Leonid Meteor Shower

Gregg Paris, guest
Gary, interviewer

Begin Podcast script:

Hello, I’m Gary, an amateur astronomer. With me is a long-time amateur, Gregg. He, too, wants to spread the word about the sky show coming on November 17th and 18th, the Leonid Meteor Shower. Hi, Gregg.

Hello, Gary, I’m glad to be here.

What do you think makes a meteor shower so special?

It’s like a fireworks show. A good one can be quite a sight.

Everyone loves to see shooting stars. Do good showers come often?

There are many all year long, but only a couple are outstanding every year. The August Perseids are consistently the best. The Leonids are variable. There have been some fantastic Leonids in the past.

Why can we predict the date for a shower?

The earth swings through the same region in space at the same time every year. If a trail of debris from a comet happens to be there too, we see more meteors almost every time.

Debris from a comet. Not the comet itself?

No, the comet is either long gone, evaporated, or its orbit has changed. But the debris cloud of dust and gravel remains. So we can see the same shower on nearly the same date for many years, in the past, and hopefully, in the future.

What comet contributed to the Leonid show?

It’s the 55P/Tempel-Tuttle. It came past the sun last in 1998. In 1998 through 2001 there were big increases in the number of Leonid meteors in those years. The counts were in the hundreds per hour. That was a lot better than the usual 10 to 15, and a bit better than the more recent 20 to 60 per hour. Last year the peak was about 100.

Were there other special years?

You know about the 1966 “Night the Stars Fell”. Tens, hundreds of thousands of meteors fell that wonderful night. In 1933 and 1899 it was disappointing, the Astronomy texts illustrate the 1866 one as spectacular, and the 1833 one as being like the end of the world.

Seems like a 33 year period is special to this shower.

The comet has a 33 and a quarter year period. That is an indication of when peaks might happen.

I think meteor shower viewing is popular.

It’s something that everyone, world wide, can enjoy for a few hours. No equipment is necessary, just good eyesight and patience.

Does one need a telescope or binoculars?

No, the whole sky is what you have to look at all at once. Just eyes alone work the best. The center of the shower, the radiant, is in the constellation Leo. But the meteors can be all over the sky, like the spokes of a giant umbrella overhead.

That’s how the shower got its name, from that location. How can one find Leo in the sky?

Most people in the Northern Hemisphere can find the Big Dipper, an asterism in Ursa Major. Just imagine the dipper is leaking. Below it, getting dripped on, is Leo, the lion constellation. If you are south and cannot see the Big Dipper, look far to the east after 3 AM. You will see six stars in a backwards question mark. The round hook is the head of Leo, the lion. The period at the bottom of the question mark is Regulus, a bright blue-white star. Last year Saturn was in Leo all year. This year Saturn is just to the east of it. Mars is just to the west of Leo. The constellation Gemini is just to the west of Mars. If you can find Gemini and Mars, you can see Leo easily. There are few other bright stars in that area.

It sounds like one might look a morning or two earlier to get familiar with that view.

Yes, people should prepare so they can have the best time out under the stars and meteors.

I hope for a dark sky on the 17th. There’s no problem with the moon on that week. Here in Southern California, there is mild weather in the fall.

Very dark sky, far from city lights, and clear weather is ideal. But it might be chilly for most people in the Northern Hemisphere. Dress warmly, have hot drinks, a lounge chair, and a clear view to the east and overhead. The whole shower might last several nights over the 10th through the 23rd with very low counts rapidly building to a peak, then going down just as fast.

What are the predictions for counts of the Leonid Meteor Shower on the night of November 17-18?

I read in this month’s Sky and Telescope magazine that ideas on that are high. Up to 500 per hour by one, 100 to 300 by a couple others. That burst should be around 21:43 Universal Time, and perhaps up to an hour later. It figures to be best for viewers in Asia in the early morning hours there. The traditional peak of 25 per hour might happen the night before, Novermber 16th-17th at about 4 AM Eastern Standard time, 1 AM Pacific Standard Time on the morning of the 17th.

You said Universal Time. How can viewers around the world relate to that?

Universal Time is zero hours midnight at Greenwich, England. That is the start of a new day for astronomers world-wide. People to the east of that 0 degree longitude line should add an hour for every time zone or 15 degrees distance. People to the west should subtract an hour for every time zone or 15 degrees distance. Here in California, we are 8 hours behind. Midnight in England on the 14th is 4 PM or 1600 Pacific Standard Time, today, the 13th.

Can you give a summary?:

1 Dress warmly if you are in autumn temperate climate.

2 Go to a dark sky location.

3 Lean back and watch the sky, particularly toward the east and overhead.

4 Everyone should watch during early morning hours till just before dawn on the night of 16th-17th for the traditional peak. For people in Asia and other eastern hemisphere locations, the early morning hours of the 18th are going to be the best time.

Thanks for all those details, Gregg. It was nice to have you talk about the Leonids.

Thanks for having me, Gary. I hope to see you under the meteor shower in a few days.

Thanks for listening to this Podcast about the Leonid Meteor Shower. I am always thrilled to see a big sky show, especially if it brings more people into the hobby of Astronomy.

Written by Gregg Paris
starryskyne@hotmail.com
10/17/09

End of podcast:

365 Days of Astronomy
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