You could think of comets as Earth’s pen pals — friends who come by to visit every couple of centuries or so, but drop us a line every year in the form of a sprinkling of meteor showers. At least, that’s true for the Lyrid meteor shower, which visits us every April despite the fact that the comet it broke off of hasn’t been anywhere near Earth since 1861.
Crash Into Me-teor
There are a lot of ways that meteor showers can form, but the most common kinds start their lives as passing comets. As a refresher, comets are giant chunks of rock and ice that have been orbiting the sun since the early days of the solar system. As they hurtle through space, they leave debris behind in their tails, and every year the planet Earth passes through chains of comet nuggets. Those chunks then burn up as they enter the atmosphere, creating a beautiful shower of shooting stars.
Every April, we smash straight through the path of comet Thatcher, which only comes within spitting distance of Earth every four centuries or so. That’s where we get the Lyrid meteor showers, which get their name from the fact that they appear to originate from the constellation Lyra. They’re some of the oldest known meteor showers on record, with sightings dating back about 2,700 years.
In 2019, the Lyrids are going to be at their peak on the morning of Tuesday, April 23. The best time to see them will be just before dawn, long after the moon has set — it’ll be a waning gibbous at this point in the month, which will be bright enough to wash out the fainter streaks. Without that additional light in the sky, however, the longer tails of the meteors will be pretty easy to spot just northeast of the bright star Vega.
Comet to America (and the Rest of the World)
It’s kind of strange to think of meteor showers coming to visit us every year when the comets they break off of are so infrequent, but that’s just how it goes. Like we mentioned earlier, the comet Thatcher last visited the planet in 1861, and its next appearance won’t be until the year 2276. It was just after its most recent pass-through that scientists made the connection between the comet and the meteors. In 1867, two different astronomers came to the same conclusion — Edmond Weiss of Vienna connected the path of the comet with the timing of the shower, and his German colleague Johann Gottfried Galle penned a mathematical proof showing that the two were linked.
It’s forgivable that people of centuries past wouldn’t have noticed any kind of correlation between an annual meteor shower and a comet that only comes every half-millennium. But people have been marveling at the Lyrids for much longer than they understood them. In one famous incident, the people of Richmond, Virginia were awoken one night in 1803 by a (false) fire alarm only to discover a sky full of streaking light. So if you make it out early enough to spot the Lyrids, you’ll be participating in a tradition several centuries old.