Halley's Comet hasn't been seen in our neck of the solar system in more than a quarter of a century, and we won't see it again until 2061.
In a sense, though, we still see Halley's Comet ― or fragments of it, anyhow ― at least once a year, in the form of the Orionids meteor shower, which peaks this weekend.
Like all comets, Halley's Comet thaws out and begins to shed tiny particles of dust, ice and rock as it approaches the sun. This stream of debris, as it reflects the Sun's light, is what gives Halley's and other comets the sometimes long, brilliant tails for which they are known.
What you might not know is that those trails of cosmic clutter linger behind long after the comet has left the glow of the Sun and vanished into the Solar System's cold, dark outer reaches.
Sometimes, the Earth's orbit takes it through these fields of comet detritus. As our planet barges through the area where the comet passed, some of those tiny fragments of dust careen into our atmosphere at several miles per second and are incinerated by friction with the air. A few are big enough, when they burn up dozens of miles above our heads, to be seen by the naked eye. The result: a meteor or "shooting star."
The Orionids are the meteor "shower" that occurs when earth passes through the debris left behind by Halley's Comet, whose roughly 76-year orbit takes it close to Earth's own.
To find the Orionids, look for Orion
The Orionids are so named because they mostly appear to radiate from a section of the sky near the constellation Orion, the hunter. Orion, which dominates the sky during the winter months, is one of the most famous and recognizable constellations. The "radiant" for the Orionids will be a bit to the left of Orion, but meteor sightings are possible anywhere in the night sky.
This year, the later you're willing to stay up, the better the chance you'll have of seeing shooting stars. The still-waxing Moon will be low in the western sky by midnight, when Orion is just getting some distance above the horizon in the eastern sky. After the moon sets, the darker sky will allow skygazers to see meteors that might otherwise get washed out by its bright light.
See the guide images with this article for help finding Orion and the Orionids meteors in the overnight sky this weekend.
By 3 a.m. Sunday, as the Orionids are starting to peak, Orion will be well over the horizon in the southern half of the sky. With the Moon gone and the Sun still hours away, a dark clear sky should afford you the chance to catch plenty of meteors. Forecasters expect a rate of about 25 meteors per hour ― a little less than one every two minutes. More optimistic estimates have called for as many as 60 meteors per hour.
You do not need binoculars or any other magnification to see meteors. What you need most is a dark sky. Kill those outdoor lights, and see if you can get your neighbors to do the same. Find a spot out in the open, away from buildings and tall trees, that lets you see as much of the sky as you can. Then get your lawn chair, a blanket, a cup of hot cocoa, and sit back to enjoy the show.
To watch the Orionids with an expert guide, visit the NASA Chats site, where NASA astronomer Mitzi Adams will be answering questions live from 11 p.m. to 3 a.m. ET on Saturday night and Sunday morning.
Should clouds obscure the view this weekend, don't fret: the Leonids, traditionally one of the year's more spectacular meteor showers, are just a few weeks away. More on them next month.