Sky and Telescope - October 2017 - 2

CONTENTS

THE ESSENTIAL GUIDE TO ASTRONOMY

FEATURES

The Milky Way's
Mysterious Gamma Rays
Is dark matter to blame for a highenergy glow in our galaxy's core?
By Monica Young

Ladder to the Stars

16 The Hunt for Planet X
Evidence is building that a large
world lurks far beyond Pluto and the
Kuiper Belt. The race to ﬁnd it is on.
By Scott S. Sheppard

OBSERVING
41 October's Sky at a Glance

COVER STORY:

22 Written in the Star
The future of our solar system
largely hangs on how the Sun ages.
Regardless of the outcome, it doesn't
look good for Earth. By Peter Tyson

30 A Gentleman's Observatory
This backyard structure recalls
classic tastes of the Victorian age.
By Tim Wetherell

Lunar Almanac & Sky Chart

Binocular Highlight
By Mathew Wedel

Planetary Almanac

62 16 Pisces, Arp 284 &
the Unexpected Quasar
A chance on a 48-inch scope brings
an awesome surprise.
By Howard Banich

CASE Y REED / S&T

DS2.3 Plus
By Rod Mollise

COLUMNS / DEPARTMENTS
4 Spectrum
By Peter Tyson

From Our Readers

75, 50 & 25 Years Ago
By Roger W. Sinnott

45 Under the Stars
By Fred Schaaf

By Fred Schaaf

News Notes

Celestial Calendar
By Alan MacRobert

New Product Showcase

Book Review
By J. Kelly Beatty

Astronomer's Workbench
By Jerry Oltion

Gallery

Focal Point
By Steven Mazlin

52 Exploring the Moon
By Charles A. Wood

54 Deep-Sky Wonders
By Sue French

Find us on
Facebook & Twitter

ONLINE

EXPLORE THE NIGHT BLOG
Follow Contributing Editor Bob King
each week as he takes readers on
an adventure through the night (or
daytime!) sky.
skyandtelescope.com/king
In 7 billion years, the
Sun will vastly swell
and brighten, threatening our planet.

S&T TEST REPORT
58 MallinCam's SkyRaider

TIPS FOR BEGINNERS
New to astronomy? From learning
the night sky to tips on buying your
ﬁrst telescope, here's everything you
need to jump into the fun.
skyandtelescope.com/letsgo

ONLINE STORE
Shop our online store for Moon and
planet globes, sky atlases, webinars,
and more, all created or chosen by
the staff of Sky & Telescope.
shopatsky.com

SKY & TELESCOPE (ISSN 0037-6604) is published monthly by Sky & Telescope, a division of F+W Media, Inc., 90 Sherman St., Cambridge, MA 02140-3264, USA. Phone: 800-253-0245
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Printed in the USA.

O C T O B E R 2 0 1 7 * SK Y & TELESCOPE

L A RRY MITCHELL

Lacaille created more of today's
constellations than anyone before
or since. By Brian Ventrudo

ON THE COVER

VOL. 134, NO. 4

46 Sun, Moon & Planets

34 The Father of
Southern Astronomy

ON THE COVER

October 2017

http://www.skyandtelescope.com/king http://www.skyandtelescope.com/letsgo http://www.shopatsky.com http://www.skyandtelescope.com

Sky and Telescope - October 2017

Table of Contents for the Digital Edition of Sky and Telescope - October 2017