Every 33 years this shower can become a huge spectacle with hundreds of meteors visible per hour at maximum. But not this year. The annual Leonid meteor shower zings from inside the Sickle of Leo, a bright, compact array of stars that resembles a backwards question mark or sickle. This time around we’re expecting to see between 15-20 meteors an hour with the peak activity expected during the early morning hours.
While that’s not a lot of meteors, it’s often enough as Leonids are swift — pinging our atmosphere at over 160,000 miles an hour (72 km/sec) — and famous for their fireballs. Unfortunately, the moon will be in waning gibbous phase right next door to Leo in the constellation Cancer. Its light will swamp many of the fainter Leonids, easily reducing the meteor count to more like 10 per hour.
That makes the shower something more for diehard meteor watchers. If you’re one of them you can watch anytime from 1 to about 6 a.m. local time Monday morning the 18th. No need to stare at the radiant. Leonids can appear anywhere in the sky but trace their point of origin back to the Sickle. It’s best to face away from the moon to keep your eyes as dark-adapted as possible, so I’d recommend looking off to the east or north to watch the show this time around.
Leonids are named for the constellation from which they originate, but they’re actually pieces of Comet 55P/Temple-Tuttle, which orbits the sun every 33 years. Earth passes through the dusty detritus the sun boils off the comet every year, and the particles slam into the atmosphere like bugs on your windshield. Only they make pretty streaks in the sky! When the comet passes near the Earth and sun every 33 years we often get a strong shower, but in off-years like this one, the numbers are much lower. Like the sun and moon, the Leonids are ever-reliable and always sprinkle a few crumbs our way every November.
In the next couple days I’ll share news of a surprise shower coming very soon!