Want to get an early start on Earth Day celebrations? Set your alarm for 3 a.m. tomorrow morning and spend an hour watching the annual Lyrid meteor shower. I’ll be out there — as long as the forecast holds. The moon sets around 1 a.m., so you can begin watching any time after. The closer to dawn, the more meteors you’ll see.
The Lyrids are the first meteor shower to pummel the sky since the touch-and-go Quadrantids in early January. That seems like an eternity ago. While not a rich downpour like the Perseids in August or December’s Geminids, the Lyrids are ever reliable, spitballing 10-20 meteors an hour across the pre-dawn sky from a dark site.
Before constellation boundaries were set, the Lyrids were associated with Lyra the Harp, the origin of their name. But in 1930, when boundaries were standardized, the shower radiant suddenly found itself in neighboring Hercules. We should be calling them Herculids, but tradition rules.
Like most meteor showers, the Lyrids originate from a particular comet with which it shares its orbit, in this case Comet Thatcher, discovered by amateur astronomer A. E. Thatcher on April 6, 1861. Thatcher — the comet not the man — orbits the sun every 415 years. When closest, solar heating vaporizes some of the comet’s dust-and-pebble-impregnated ice, sending the debris into space to form a tail. After many such passes, the material spreads out to pepper Thatcher’s orbit like a kid leaving a trail of dirt crumbs on the floor after playing outside. Each year in late April, Earth slams headlong into the comet debris. Bits of dust and rock flare into streaks of light when they strike the atmosphere at 46 kilometers a second (102,600 mph). One after another they arrive, emanating from a spot in the sky called the radiant.
The radiant is a perspective effect caused by incoming meteoroids from Comet Thatcher arriving at Earth on parallel paths. Something similar happens when you drive through a heavy rain or snowstorm at night. Flakes and drops in the car’s headlights appear to stream in parallel from a point in the distance. Essentially, Earth’s a car driving into a cometary dust storm. Watching a meteor shower is one way to directly experience our planet orbiting the sun.
Meteor-shower-watching requires only the fortitude to get up for an hour or two in the middle of the night and a reclining chair. Since you’ll be lying still and April dawns can be chilly, dress as if it’s January: bomber hat, lined books, gloves and down coat. I grab a wool blanket or sleeping bag, crack open my squeaky recliner and get cozy under a blanket. The rest is pure relaxation. Night meditation. Simply lie back and wait for the meteors to come while soaking up the cosmic view.
The darker the sky, the more meteors you’ll see. Since most of us put up with some amount of light pollution, 10-12 Lyrids an hour might be a better estimate of how many you’ll see. In addition to shower members, you’ll notice sporadics. These are random meteors not associated with the Lyrids that appear at the rate of about 5-7 per hour. Lyrids can appear anywhere in the sky, but they all point back to the radiant; sporadics come from any direction.
You may want to make an informal count during the night to keep track of how many you see. I do. And be prepared for times when not a single meteor shows for 5 minutes or longer. With smaller showers like the Lyrids, patience is a virtue. If you’d like go a step further and contribute to better understanding the shower’s long-term evolution, register for free with the International Meteor Organization, then download a report form here.
To sum up:
* Set your clock for 2 or 3 a.m. Sunday morning and spend at least an hour watching.
* Dress warmly and observe from a comfortable chair.
* Face away from glaring electric lights to allow your eyes to adapt to the dark. You can look in any direction, but facing south or east allows you to see both the
“shorty” meteors near the radiant and longer ones that flash farther away from it.
* Keep your expectations low. The Lyrids have occasional outbursts when quadruple the normal number of meteors are seen, but the next flare-up isn’t expected until 2040.
Clear skies! If we’re lucky, maybe the aurora will return. Watching the shower on Earth Day reminds us that our planet is a full participant in the affairs of the solar system.