Space is littered with cosmic clutter, leaving hardly a clear path for Earth as it orbits the sun. When we pass through this cosmic debris, frozen gas and space dust, it often falls and burns up in our atmosphere resulting in streaks of light—sometimes even spectacular fireballs—known as meteors.
Each year, between the period of January through mid-April, Earth enters a meteor “drought,” when this space debris becomes scant. But come mid-April, a meteor shower known as the Lyrids snaps that dry spell as Earth enters the debris trail left by Comet Thatcher. The resulting yearly light show that rains down upon Earth gives new meaning to the term “April showers.”
This year, the Lyrids run from April 15 to 29 but their peak viewing period will be from late evening on April 21 until dawn on April 23, locally, starting before midnight and lasting until morning. The cosmic debris trail is at its thickest then as Earth plows through during this peak period.
How to Catch an April Meteor Shower
On the nights of April 21 and 22, in the Northern Hemisphere, the constellation Lyra will rise before midnight in the northwest of the sky’s dome and will reach its highest position at dawn. The new moon falls on April 19, meaning there will be pitch-dark lunar conditions for optimal meteor viewing, notwithstanding artificial urban light that may interfere. Those seeking to catch a glimpse of the Lyrids should find a vantage point in a dark location with plenty of sky visible.One needn’t look directly to the radiant for shooting stars for the radiant is merely the point from which they seem to emanate. Those streaks of light will, in fact, travel across the entire sky.
Star watchers in the Southern Hemisphere will face a much tougher prospect spotting the Lyrids: those in mid-latitudes below the equator won’t see much at all until the hours before dawn, local time. They'll see fewer meteors emanating from the radiant than sky gazers in the Northern Hemisphere, if any at all, meanwhile the constellation Lyra won’t rise very high in the sky. But don’t lose heart entirely; there still might be a few to spot.
Where Do Lyrid Meteors Come From?
The comet responsible for causing all this litter was dubbed Comet Thatcher after its discoverer, Alfred E. Thatcher, saw it for the first time in 1861. Shining dimly with a magnitude of 7.5, it was too faint for human eyes to make out at first, but became significantly brighter as it neared the sun until disappearing into the evening twilight in June 1861. Thatcher spotted the comet with a 4.5-inch-diameter 30x refracting telescope.A comet is, in fact, an extraordinarily humongous system of cosmic matter, spanning millions of miles, traveling in orbit around the sun—much like the nine planets of our solar system do—along an elliptical path that is almost unfathomably massive.
It is the comet’s nucleus—the amorphous solid center, a conglomeration of frozen gas and cosmic dust—that becomes most visible to observers. This nucleus is what sheds its gaseous matter and emits its almost supernatural-seeming, often green-tinged glow when nearing the sun. It is often a once-in-a-lifetime spectacle to behold.
Alfred E. Thatcher saw the comet’s nucleus when it neared its perihelion—when an object is closest to the sun along its elliptical orbit—as it passed close to Earth and became quite visible to the naked human eye.
Comet Thatcher has long since departed our solar system, and it will take 417 years to make its revolution around the sun before returning. It will reach its aphelion—furthest distance from the sun—around the year 2070 and won’t return near Earth again until the year 2278. So good luck spotting Comet Thatcher!
Meanwhile, while we await Comet Thatcher’s return, we can enjoy the meteor shower that it spawned. It will continue to reappear every mid-April as Earth mashes through its detritus. And the Lyrids will continue to break the cosmic drought faithfully, every year, appearing to emanate from near the bright star Vega.
