Get Out: Orionid Meteor Shower Peaks Overnight
Robert Roy Britt , Editorial Director
space.com – Tue Oct 20,
12:30 pm ET
The Orionid
meteor shower is expected to put on a good show tonight into
the predawn hours Wednesday, weather permitting.
This annual
meteor shower is created when Earth passes
through trails of comet debris left in space long ago by
Halley's Comet. The "shooting stars" develop when
bits typically no larger than a pea , and mostly sand-grain-sized,
vaporize in Earth's upper atmosphere.
"Flakes of comet dust hitting the
atmosphere should give us dozens of meteors per hour," said Bill
Cooke of NASA's Meteoroid Environment Office.
People in cities and suburbs will see far fewer meteors, because
all but the brightest of them will be overpowered by light
pollution. The best view will be from rural areas
(the moon will not be a factor, so dark skies
will make for ideal viewing).
When and how to watch
The best time to watch will be between 1 a.m. and dawn local
time Wednesday morning, regardless of your location. That's when
the patch of Earth you are standing on is barreling headlong into
space on Earth's orbital track, and meteors
get scooped up like bugs on a windshield.
Peak activity, when Earth wades into the densest part of the
debris, is expected around 6 a.m. ET (3 a.m. PT).
Some meteors could show up late tonight, too. Late-night viewing
typically offers fewer meteors, however, because your patch of
Earth is positioned akin to the back window of the speeding
car.
The Orionids have been strong in recent
years.
"Since 2006, the Orionids have been one of the best showers of
the year, with counts of 60 or more meteors per hour," Cooke
said.
Some of those counts come in flurries, so skywatchers should
find a comfortable spot with as wide a view of the sky as possible.
Lie back and allow 15 minutes for your eyes to adjust to the
darkness, then give the show at least a half hour to play out
through spurts and lulls. Meteors could appear anywhere in the sky,
though traced back they will appear to emanate from the
constellation Orion.
Telescopes and binoculars are of no use, because meteors move
too quickly. Extra warm clothing is a must, and a blanket and
pillow or lounge chair allows comfortable positioning so you can
look up for long stretches.
Reliable event
Predicting meteor
showers is tricky because the debris comes from multiple
streams.
Each time comet Halley passes around the sun on its elongated
orbit – every 76 years – it lays down a fresh track of debris for
Earth to plow through in subsequent years. Those tracks spread out
and mingle over time, and we pass the tracks each October during
our 365-day, nearly circular trek around the sun.
Japanese researchers Mikiya Sato and Jun-ichi Watanabe say
activity in recent years is related to debris put in place from
1266 BC to 911 BC, and this could be another good year, according
to NASA.
Even if that prediction does not hold, the Orionids will almost
surely put on a decent show. Prior to 2006 and going back many
years, the
Orionids have produced a reliable 15 to 20
meteors per hour at the peak, for skywatchers with dark skies.
As a bonus, this time of year you can expect an additional five
to 10 sporadic meteors per hour – those not related to the
shower.