April is currently a great month for lovers of the night sky. We had a geomagnetic storm that led to lower-latitude and more intense Northern Lights, the first Full Moon of spring, the Pink Moon, a rare four-planet planetary alignment happening right now, and the first meteor shower since January, the Lyrids, which peaks tonight.
The Lyrids are not considered a particularly spectacular meteor shower year on year but they are consistent. From April 15 to 29, this meteor shower will streak across the sky, with its peak expected in the early hours of April 22, according to the International Meteor Organization. They are called Lyrids as they appear to come from the direction of the Lyra constellation, whose brightest star Vega, is easy to spot.
Although the full Moon waning means it will still be bright enough to make observations more difficult unless you stay up into the early hours, with good conditions, you should see about 18 meteors per hour visible across the sky.
These meteors are the trail of debris left in the inner Solar System by Comet C/1861 G1 Thatcher as it orbits the Sun. This long-period comet completes its trek around our star every 415 years or so. It was first observed in 1861 so the next time around will be from 2276 onwards, making it a bit unlikely that any of us will be watching it (but you never know).
Despite its long period, the gravitational influences of the planets have a shorter-term effect on the debris leftover. Every 60 years or so, the wake of debris comes straight into Earth’s orbit boosting the event for one season. The last time it happened in 1982, observers counted around 90 shooting stars per hour at its peak. This means we have to wait for another 20 years for the next.
This occasional surge has been crucial to making the Lyrids so well-known across history. They are in fact one of the oldest known meteor showers, For example among the most incredible showers in history is the Lyrids peak of 1803, when up to 700 meteors an hour were witnessed raining down by a journalist in Richmond, Virginia.
An equally impressive event comes from almost 2,000 years earlier described in the Zuo Zhuan, an ancient Chinese narrative history, that described a Lyrids meteor shower as the "stars fell like rain" in 687 BCE. This meteor shower is even mentioned in Australian Indigenous Astronomy, which extends even more millennia into the past.