Tonight – August 11, 2015 – it’s time to watch the Perseid meteor shower. The moon is out of the way, so the meteors should be flying! This shower is often our best meteor shower of the year, and it’s definitely a sky highlight of Northern Hemisphere summers. At its peak, the Perseids often rain down 50 to 100 or more meteors per hour. To see the most meteors, you will want to watch in the hours between midnight and dawn. Which dates are best? We recommend watching all three mornings around the peak – the mornings (not the evenings) of August 12, 13 and 14. If you can just watch one, the morning of August 13 probably will feature the most meteors for those with clear, dark country skies. The tips below can help you enjoy.
1. Watch between midnight and dawn. Most meteor showers are best after midnight, and the Perseids are no exception. After midnight, the part of Earth you’re standing on has turned into the meteor stream. That means the radiant point for the shower will be above your horizon. The chart at the top of this point shows the radiant for the Perseids. If you’re in the Northern Hemisphere, it’s up in the northeast around midnight or just a bit after. After the radiant rises, you’ll see more meteors.
4. Try observing in the evening hours. You won’t see as many meteors during the evening hours, and the shower will be past its peak on those nights. But you still might catch an earthgrazer, which is a slow-moving and long-lasting meteor that travels horizontally across the sky. If you see one, you’ll have a new appreciation for evening meteor watching.
6. Watch for meteor trains. A meteor train is a persistent glow in the air, left by some meteors after they have faded from view. Trains are caused by luminous ionized matter left in the wake of this incoming space debris. A good percentage of Perseids are known to leave persistent trains. They linger for a moment or two after the meteor has gone. Watch for them!
7. If you’re in the Southern Hemisphere … watch, anyway! At temperate latitudes in the Southern Hemisphere, the radiant of the Perseid meteor shower never gets very high in the sky. Therefore, the number of Perseid meteors seen from this part of the world isn’t as great as at more northerly latitudes. But if you’re game, look northward in the wee hours before dawn on August 12, 13 and 14, and you might still see a sprinkling of Perseids.
8. As dawn is breaking, will you see Mars? As the predawn sky gives way to morning twilight, perhaps you’ll catch the old waning crescent moon and the planet Mars below the stars of the constellation Gemini the Twins. Those stars are Castor and Pollux. What a way to cap a night of meteor watching! (See sky chart below.)
Here’s a tip for future reference. Be aware that – in years when the moon is interfering with the shower – you can sprawl out in a moon shadow. Fortunately, the slender waning crescent moon won’t interfere with this year’s meteor shower. However, in years when the moon is up around the shower’s peak dates, it can cast looooong shadows at early evening and before dawn. In that case, be aware that you can find a moon shadow somewhere that still provides a wide expanse of sky, to vastly improve your view of the meteor shower. A plateau area with high-standing mountains to block out the moon works just fine. If you can’t do that, find a hedgerow of trees bordering a wide open field somewhere (though obtain permission, if it’s private land). Or simply sit in the shadow of a barn or other building. Ensconced within a moon shadow, and far from the glow of city lights, the night all of a sudden darkens while the meteors brighten.
Bottom line: With almost no moon to ruin the show, the year 2015 is a favorable one for watching the annual Perseid meteor shower. Here are some tips for watching the 2015 Perseid shower. We recommend watching all three mornings around the peak – the mornings (not the evenings) of August 12, 13 and 14.