Perseid meteor shower: Coming soon to a sky near you

Perseid meteor shower: Beloved by skywatchers, 2013 will be an excellent one for the Perseid meteor shower. The moon will set before midnight on the peak Perseids nights.

|
(AP Photo/Ron Garan - NASA)
NASA Astronaut Ron Garan, Expedition 28 flight engineer, tweeted this image from the International Space Station on Sunday Aug. 14 2011 with the following caption: "What a 'Shooting Star' looks like from space, taken yesterday during Perseid Meteor Shower."

Get ready to start looking up this summer.

For Northern Hemisphere observers, the latter half of July on into August is usually regarded as "meteor viewing season," with one of the best displays of the year reaching its peak in mid-August.

The annual Perseid meteor shower is beloved by everyone from meteor enthusiasts to summer campers, and 2013 will be an excellent one for the Perseids. The moon will set before midnight on the peak nights of Aug. 11 and 12, meaning dark skies for prospective observers. [See Amazing Perseid Meteor Shower Photos of 2012]

This week, however, let's concentrate on some of the lesser-known summer meteor displays. 

In general, Earth encounters richer meteoric activity during the second half of the year, and stargazers are more likely to see twice as many meteors per hour in the predawn hours as compared with the evening hours. During the premidnight hours, the United States is on the "trailing" side of the Earth due to our orbital motion through space. Any meteoric particle generally must have an orbital velocity greater than that of the Earth to "catch" the planet.

After midnight, when the United States is  turned onto the Earth's "leading" side, any particle that lies along the Earth's orbital path will enter the planet's atmosphere as a meteor.  As such, objects collide with the atmosphere at speeds of 7 to 45 miles per second (11 to 17.7 kilometers per second), their energy of motion rapidly dissipates in the form of heat, light, and ionization, creating short-lived streaks of light popularly referred to as "shooting stars."

Summertime meteors, occasionally flitting across your line of sight, are especially noticeable between mid-July and the third week of August. Between Aug. 3 and 15, there are no fewer than six different active minor displays. These six meteor showers are listed in the table below.

The actual number of meteors a single observer can see in an hour depends strongly on sky conditions, but the only equipment you'll need to see them are your eyes and a modest amount of patience.

The rates given in the table are based on a limited star magnitude of +6.5 (considered to be the faintest star visible to the naked eye without the use of binoculars or a telescope), an experienced observer, and an assumption that the radiant is directly overhead.

The radiant is the place in the sky where the paths of meteors, if extended backward, would intersect when plotted on a star chart.  Your clenched fist held at arm's length is equal to roughly 10 degrees on the sky.  So if the radiant is 30 degrees ("three-fists") above the horizon, the hourly rate is halved; at 15 degrees, it is one-third.

While the hourly rates from these other meteor streams provide but a fraction of the numbers produced by the Perseids, combined, overall they provide a wide variety of meteors of differing colors, speeds and trajectories. 

Among these are the southern Delta Aquarids, which can produce faint, medium-speed meteors; the Alpha Capricornids, described as bright yellowish meteors  and the Kappa Cygnids, which sometimes produce fireballs.  As such, if you stay out and watch long enough, you may be nicely rewarded for your time spent.  

Note that five of the six showers listed come from the region around the constellations of Aquarius and Capricornus. These constellations are highest in the southern sky between roughly 1 a. m. and 3 a.m. Eastern time. The Kappa Cygnids appear to emanate from the constellation Cygnus, which will appear more or less overhead within an hour of local midnight.

Currently, the one drawback in watching for meteors is a bright gibbous moon, which this weekend will wane to last quarter on Sunday. 

As Robert Lunsford of the American Meteor Society points out, "the waning gibbous moon will rise later during the evening hours, but will still be in the sky during the more active morning hours, causing considerable interference with meteor viewing."

After Sunday, the moon will diminish to a crescent phase, continuing to wane in both phase and brightness and will become significantly less of a hindrance to viewers as well as rising progressively later in the night.  It will be new on Aug. 5.

Editor's Note: If you have an amazing night sky photo of any celestial sight that you'd like to share for a possible story or image gallery, please contact SPACE.com Managing Editor Tariq Malik at spacephotos@space.com.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y. Follow us @Spacedotcom, Facebook and Google+. Original article on SPACE.com.

Copyright 2013 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Perseid meteor shower: Coming soon to a sky near you
Read this article in
https://www.csmonitor.com/Science/2013/0727/Perseid-meteor-shower-Coming-soon-to-a-sky-near-you
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe