Astronomy

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in the United
States who can
spend the night
outdoors should
begin observ-
ing at the end of
astronomical twi-
light on the 12th
and watch the sky
until dawn.
August 12 isn’t
the only night you can observe Perseids.
This year, the shower will be active
between about July 17 and August 24. Of
course, you’ll see fewer meteors the further
you observe from the date of the peak.
Early in the evening on August 12, set
up a lawn chair (preferably one that
reclines), face east, and look a third to half

of the way up in the sky. Bright meteors

that travel near the top of the atmosphere

and leave long trails are more common at

this time. As the radiant rises (remember,

you can use the Double Cluster to approxi-

mate it), adjust your gaze to keep watching

a point about 45° west of it. Glancing

around is OK. In the early morning hours,

after the radiant has crossed the meridian

— the imaginary line from north to south

that divides the eastern half of the sky from

the west — and begins to sink lower in the

northwest, you might want to change your

view and look 45° east of the radiant.

If you’re observing in a group, let those

around you know when you spot a bright

Perseid. Some meteor trails last for several

seconds, and glowing trains may remain

long after the meteors’ light fades.

How many Perseids will you see?

Meteor counters use a quantity called the

zenithal hourly rate (ZHR). This is the

number of meteors visible per hour for an

observer under a dark sky with no scat-

tered light and with the radiant positioned

directly overhead. The ZHR for the

Perseids is 110. This year, with the Moon

out of the sky, you can expect to count

between 80 and 90 meteors per hour from

a dark site — a terrific rate!

All meteor showers are exciting events,

but this summer’s Perseids rank at the top.

Be comfortable, have fun, and get ready for

some oohs and aahs.

Astronomy Senior Editor Michael E. Bakich

has spent countless summer nights through the

years observing the Perseids.

A Perseid streaks

between the Pleiades

(M45) and the Hyades

in Taurus above

Pasargadae, a UNESCO

World Heritage site

near Shiraz, Iran, on

August 12, 2015. This

20-second exposure

at ISO 3200 was taken

with a Canon 5D Mark

II and an f/1.4 Samyang

24mm lens set at f/2.8.

While taking a

wide-field shot

of the Andromeda

Galaxy (M31) on

August 14, 2015, this

imager captured a

Perseid in one of his

exposures. He used

a Canon T2i with a

50mm lens at f/1.4

and stacked five

13-second exposures

taken at ISO 1600.

TIMOTHY BENKO/NEW JERSEY ASTRONOMICAL ASSOCIATION

LARRY KUHN

AMIRREZA KAMKAR