Perseids Meteor Shower; Just the Facts!

Image Credit & Copyright: Jakob Knutsson from Falun, Sweden on August 21, 2016. See his links below.

Synopsis: Saturday night, August 12, until pre-dawn twilight on Sunday, August 13 the annual Perseids meteor shower will be at its peak.  As with all meteor showers there’s an estimated viewing window or, “active dates” which in this case run from mid-July to late-August.  Peak viewing however is usually narrowed down to a few days or even a single night through the following morning.

This year’s peak hourly rates will be around 50-75 per hour and you will want to be looking in the general direction of Perseus in the north.  This is a primarily Northern Hemisphere show but the big floodlight in the night sky (the Moon) will be in its waning gibbous phase so it will rise around midnight and that will likely diminish the show somewhat for the best part of the night.

Fast Facts:

Shower Name: Perseids

Active Dates: Mid July through late August.

Peak Viewing: Night of Saturday, August 12 until pre-dawn twilight on Sunday, August 13.

Hourly Rates: Approximately 80-100 per hour.

Radiant Point: North in the general direction of the constellation Perseus.

Moon Impact = Moderate! The waning gibbous moon, 78% illuminated will rise around 22:50 and remain a problem through sunrise. This will likely cut the number you can see in half.

Velocity: 37 mi. (59 km) per second.

Parent Body: Comet 109P Swift-Tuttle. With a nucleus of about 16 mi. (26 km) this comet is the largest known object to repeatedly pass by the Earth with the last time being in 1992 and the next pass in 2126.

Hemisphere Favored: Northern Hemisphere.

Traits: The Perseids tend to display more fireball (bolide) meteors than any other meteor shower of the year. That being said, these things are based on past performance and predicting how many (if any) there will be this time is impossible. If you do see one, look closely the moment it ends, you may see a faint smoke trail.

Notes and Information:

Moonlight: For each meteor shower, I offer a Moonlight impact rating from NULL to MODERATE and MAXIMUM based on its age, phase, illumination and rise-set times. New through 1st quarter phases rarely causes any trouble as these young crescents set fairly early. Full through last quarter phases are what really cause the heartache as they are up most of the night and or rise late, impairing those peak pre-dawn viewing times. Of course, none of this matters if it’s cloudy so check the weather.

Quick Moon Reference: First Quarter Moon; rises around noon which means it’s already up and overhead at sunset and sets around midnight.

Full Moon; rises in the east roughly around sunset, is up all night (usually highest around midnight) and sets at sunrise.

Third (last) Quarter Moon; rises around midnight, is high overhead around sunrise and sets around noon.

How many meteors will I see?: It’s important to keep in mind that meteor shower predictions are just that; predictions based on past totals so just because it says “X” per-hour you have to understand that predicting these things are about as accurate as weather prediction. Also, when you see “X” per-hour, that rate is assuming that you have an open 360 degree view, at a dark sky location, on a clear night and with the radiant point directly overhead. That being said, your totals (like mine) will probably be half of what’s predicted if you’re viewing from your back yard and you’re within 30 minutes or so of a medium sized city and you can probably half that again if the Moon is up and larger than a small, few day-young or old-crescent.

When’s the best time to look?: Peak viewing is typically a given night as well as the following morning with emphasis on the following morning being the absolute best time to watch. In fact, the closer to morning you can get without twilight creeping in the better; here’s why. If you were to view the solar system from the “top” or “above,” you’ll quickly notice that the planets orbit the Sun in a counter clockwise motion and most also rotate in a counter clockwise motion as well, Earth included (Venus and Uranus are the exceptions). That means just before sunrise, Earth is pointed in the direction of travel in its orbit and meteors are mere bugs or snowflakes hitting the windshield of Spaceship Earth.

Where should I look?: You will want to look in the direction of what’s called the “radiant point” of the shower for best results. The radiant point is where it appears that the meteors radiate from; which is usually associated with the constellation they are named after. For example; the radiant point for the Orionids will be the constellation of Orion. Also the higher that the radiant point gets the better observing may become because meteors radiate out in all directions and most aren’t readily visible until they’re approximately 30 degrees or so from their radiant point.

What do I need?: As for seeing them, nothing. The most important things you need are a clear, dark sky, preferably with a nice wide open horizon and no Moon. In fact you really can’t use tools like binoculars or telescopes for meteor showers because the streak is too long and you simply won’t be able to move your equipment into position in the less than a breath that the meteor streak lasts.

Considerations: are weather and subsequently how you plan to dress for that weather. Red flashlights will help save your eyes because dark adaptation is a key in picking out the faint streaks you won’t be able to see after you just check your cell phone. Besides that, good people, chair, blankets, bug spray, food and try not to lie on any ant hills.

Jakob Nutsson:






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