Do you remember Halley’s comet? The last time this famous object was visible was in 1986, 36 years ago.
Younger readers may remember little or nothing of this famous cosmic wanderer (it takes about 75 years to go around the sun once; your next chance will come in the summer of 2061). Or maybe, if you were out there at the time, you didn’t see Halley’s Comet at all due to light pollution or the comet’s low altitude above the horizon.
Either way, if you missed the 1986 event, or don’t want to wait until the comet’s next flyby in 2061, you might want to head out before dawn for the next few mornings and try to spot some “cosmic.” trash”, a meteor shower made up of debris left behind in space by Halley’s Comet.
Related: Eta Aquarid Meteor Shower 2022: When, where and how to see it
The birth of a meteor shower
Meteorites are the remnants of the fully or partially broken nucleus, or solid core, of comets. The swarms of tiny particles, usually no larger than pebbles and grains of sand, come from or formed with comets. These particles generally stay close to and along the comet’s orbit.
This material is originally “clumped” but eventually disperses along the main comet’s orbital path. If the swarm of particles is old enough, the cometary debris is more or less evenly distributed along the orbit of the parent comet. In other words, meteoroids are fairly evenly distributed throughout their orbit around the sun. Because of this, the Earth, when passing through the orbit of the main comet (or passing very close to it), will receive a meteor shower of greater or lesser intensity at about the same time each year.
It turns out that Halley’s Comet’s orbit comes very close to Earth’s orbit in two different places. One point is in mid to late October, on the inbound leg of this comet’s approach to the sun, producing a meteor display known as the Orionids. The other point arrives in early May, on the outgoing leg of the comet, producing what is known as the Eta Aquarid meteor shower.
If you’re hoping to capture photos of Eta Aquarids, our guide on how to photograph meteor showers can help. Check out our best astrophotography cameras and best astrophotography guide lenses to prepare for the next meteor shower.
when and where to watch
According to Margaret Campbell-Brown and Peter Brown in the Royal Astronomical Society of Canada’s 2022 “Observer’s Handbook,” the Eta Aquarid meteor shower is predicted to peak early Friday morning (May 6). Under ideal conditions (a dark, moonless sky), you can see 40 to 60 of these speeding meteors per hour, one of the best of the major annual meteor displays. The brightest of these meteors leave bright, long-lasting trails behind them. And since the crescent moon has set before 1 am local time, this is one of those years when viewing conditions will be perfect. This shower appears at a maximum strength of about a quarter for about two to three days before and after May 6.
However, there is a downside if you plan to watch these meteors this year, at least for those watching from north of the equator. The radiant (the point of emanation of these meteors) is near the asterism popularly known as the “Water Pitcher” in the constellation of Aquarius, the Water Bearer, which rises above the eastern horizon at around 2:30 am local time.
Now, from the southern hemisphere, the Eta Aquarids are considered the best meteor display of the year. In places like Melbourne, Australia, Dunedin, New Zealand, Santiago, Chile, and Cape Town, South Africa, the Aquarius Water Pitcher rises more than half of the eastern sky at first light, allowing skygazers to meteors Enjoy an excellent meteor show for a few hours.
However, it’s a very different story for meteor watchers living north of the equator, as the Aquarian Water Pitcher never rises very high in the sky when viewed from northern latitudes. And shortly after it first appears, the first light of dawn begins to illuminate the eastern sky. Taken together, these factors make it very difficult for those living in the Northern Hemisphere to see the meteor shower.
Because of this, the actual rates seen are typically much lower than the often quoted 40 to 60 per hour.
From the United States, typical fares are:
30 meteors per hour at 21 degrees north latitude (Honolulu, Hawaii),
25 meteors per hour at 26 degrees north latitude (Brownsville, Texas; Naples, Florida),
15 per hour at 35 degrees latitude (Albuquerque, New Mexico; Chattanooga, Tennessee),
Only 10 per hour at 40 degrees (Philadelphia, Pennsylvania; Salt Lake City, Utah).
Approximately 5 or less north of latitude 45 (Bangor, Maine; Seattle, Washington).
Catch an earth scraper
For most sky watchers, one of the best results of seeing a meteor shower is glimpsing a meteor emerging from the radiant and skimming horizontally across the atmosphere, like a bug brushing against the side window of a car. Meteor watchers call these shooting stars “earth grazers.”
These “ground grazers” leave colorful and long-lasting trails. “These meteors are extremely long,” says Robert Lunsford of the American Meteor Society. “They tend to hug the horizon rather than shoot overhead, where most cameras aim.” “The grazers are rarely numerous,” warns Bill Cooke, a member of NASA’s Space Environments team at the Marshall Space Flight Center. “But even if you only see a few, chances are you’ll remember them.”
If you see one early in the next few mornings, be aware that you’ll likely see the glowing beam produced by material that originated in the nucleus of Halley’s Comet. When these tiny cometary fragments collide with Earth, friction with our atmosphere elevates them to white heat, producing the effect popularly known as “shooting stars.”
Put another way: Like all comets, Halley is a cosmic bug and as such leaves behind a trail of—for lack of a better term—garbage, made up of tiny bits and pieces of space debris that can produce beautiful incandescent contrails when impacting our atmosphere.
In a way, I guess you can call them “rock stars”, but eventually they fall to Earth.
Publisher’s note: If you take an amazing photo of an Eta Aquarid meteorite or any other night sky sight and would like to share it with Space.com for a story or image gallery, please send images, comments and location information to firstname.lastname@example.org.
Joe Rao is an instructor and guest speaker at New York’s Hayden Planetarium. write about astronomy natural history magazinethe farmers almanac and other publications. Follow us on twitter @Spacepointcom and in Facebook.