In the Northern Hemisphere, the annual August Perseid meteor shower
probably ranks as the all-time favorite meteor shower of the year. This
major shower takes place during the lazy, hazy days of summer, when many
families are on vacation. And what could be more luxurious than taking a
siesta in the heat of the day and watching this summertime classic in
the relative coolness of night? This shower is visible in the Southern
Hemisphere, too, though to a lesser extent. No matter where you live
worldwide, the 2013 Perseid meteor shower will probably be at its best
on the nights of August 11-12 and/or August 12-13. Try the nights
before and after that, too. Before dawn viewing is best. From
northerly latitudes, you often see 50 or more meteors per hour, and from
southerly latitudes in the Southern Hemisphere, perhaps you’ll see
about one-third that many meteors.
When is the best time to view the Perseid meteor shower?
Don’t wait until the peak nights to watch for the Perseid meteors.
You can start watching a week or more before the peak nights of August
11-12 and 12-13, assuming you have a dark sky. The Perseid shower is
known to rise gradually to a peak, then fall off rapidly afterwards. So
as the nights pass in the week before the shower, the meteors will
increase in number.
As a general rule, the Perseid meteors tend to be few and far between
at nightfall and early evening. Yet, if fortune smiles upon you, you
could catch an earthgrazer – a looooong, slow, colorful meteor
traveling horizontally across the evening sky. Earthgrazer meteors are
rare but most exciting and memorable, if you happen to spot one. Perseid
earthgrazers can only appear at early to mid-evening, when the radiant
point of the shower is close to the horizon.
As evening deepens into late night, and the meteor shower radiant
climbs higher in the sky, more and more Perseid meteors streak the
nighttime. The meteors don’t really start to pick up steam until after
midnight, and usually don’t bombard the sky most abundantly until the
wee hours before dawn. You may see 50 or so meteors per hour in a dark
sky.
How to watch the Perseid meteor shower. You need no
special equipment to enjoy this nighttime spectacle. You don’t even
have to know the constellations. But you’ll definitely want to find a
dark, open sky to fully enjoy the show. It also helps to be a night owl.
Give yourself at least an hour of observing time, for these meteors in
meteor showers come in spurts and are interspersed with lulls.
An open sky is essential because these meteors fly across the sky in
many different directions and in front of numerous constellations. If
you trace the paths of the Perseid meteors backward, you’d find they
come from a point in front of the constellation Perseus. But once again,
you don’t need to know Perseus or any other constellation to watch this
or any meteor shower.
Enjoy the comfort of a reclining lawn chair and look upward in a dark
sky, far away from pesky artificial lights. Remember, your eyes can
take as long as twenty minutes to truly adapt to the darkness of night.
So don’t rush the process. All good things come to those who wait.
What’s the source of the Perseid meteor shower?
Every year, from around July 17 to August 24, our planet Earth crosses
the orbital path of Comet Swift-Tuttle, the parent of the Perseid meteor
shower. Debris from this comet litters the comet’s orbit, but we don’t
really get into the thick of the comet rubble until after the first week
of August. The bits and pieces from Comet Swift-Tuttle slam into the
Earth’s upper atmosphere at some 210,000 kilometers (130,000 miles) per
hour, lighting up the nighttime with fast-moving Perseid meteors. If our
planet happens to pass through an unusually dense clump of meteoroids – comet rubble – we’ll see an elevated number of meteors. We can always hope!
Comet Swift-Tuttle has a very eccentric – oblong – orbit
that takes this comet outside the orbit of Pluto when farthest from the
sun, and inside the Earth’s orbit when closest to the sun. It orbits the
sun in a period of about 133 years. Every time this comet passes
through the inner solar system, the sun warms and softens up the ices in
the comet, causing it to release fresh comet material into its orbital
stream. Comet Swift-Tuttle last reached perihelion – closest point to the sun – in December 1992 and will do so next in July 2126.
Although the Perseid meteor shower gives us one of the more reliable
productions of the year, the ins and outs of any meteor shower cannot be
known with absolute certainty. Forecasting the time and intensity of
any meteor shower’s peak – or multiple peaks – is akin to predicting the
outcome of a sporting event. There’s always the element of surprise
and uncertainty. Depending on the year, the shower can exceed, or fall
shy, of expectation.
The swift-moving and often bright Perseid meteors frequently leave persistent trains
– ionized gas trails lasting for a few moments after the meteor has
already gone. Watch for these meteors to streak the nighttime in front
of the age-old, lore-laden constellations from late night until dawn as
we approach the second weekend in August. The Perseids should put out a
few dozen meteors per hour in the wee hours before dawn on the nights of
August 10-11, 11-12 and 12-13.
Why is this shower called the Perseids? If you
trace all the Perseid meteors backward, they all seem to come from the
constellation Perseus, near the famous Double Cluster. Hence, the meteor
shower is named in the honor of the constellation Perseus the Hero.
However, this is a chance alignment of the meteor shower radiant with the constellation Perseus. The stars in Perseus are light-years
distant while these meteors burn up about 100 kilometers (60 miles)
above the Earth’s surface. If any meteor survives its fiery plunge to
hit the ground intact, the remaining portion is called a meteorite. Few –
if any – meteors in meteor showers become meteorites, however, because
of the flimsy nature of comet debris. Most meteorites are the remains of
asteroids.
In ancient Greek star lore, Perseus is the son of the god Zeus and
the mortal Danae. It is said that the Perseid shower commemorates the
time when Zeus visited Danae, the mother of Perseus, in a shower of
gold.
In our day and age of expanded artificial lighting, fewer and fewer
people have actually seen the wonders of an inky black night sky. Why
not make a date with the Perseid meteor shower this year and witness one
of nature’s most remarkable sky shows?
Simply find a dark, open sky, enjoy the comfort of a reclining lawn chair and make a night of it!
Bottom line: No matter where you live worldwide, the 2013 Perseid
meteor shower will probably be at its best on the nights of August 11-12
and/or August 12-13. Before dawn viewing is best. From northerly
latitudes, you often see 50 or more meteors per hour, and from southerly
latitudes in the Southern Hemisphere, perhaps you’ll see about
one-third that many meteors.