Astronomy - September 2015

CONTENTS

4 ASTRONOMY • SEPTEMBER 2015

24

Starmus will honor
Stephen Hawking in 2016
Next summer, the science festival
will revolve around the life of the
renowned theoretical physicist.
DAVID J. EICHER

28 COVER STORY

Multiverses: Science or
science fiction?
BOB BERMAN explores the strange
ideas that drive theorists to be-
lieve in parallel universes.

34

Ask Astro
Moon musings.

36

The Sky this Month

Totality’s long embrace.

MARTIN RATCLIFFE AND

ALISTER LING

38

StarDome and

Path of the Planets

RICHARD TALCOTT;

ILLUSTRATIONS BY ROEN KELLY

44

Rendezvous with an

evolving comet

As Comet 67P/Churyumov-

Gerasimenko heads closer to the

Sun and grows more active, the

Rosetta and Philae spacecraft

scrutinize its complex behavior.

RICHARD TALCOTT

50

The weirdest star

in the universe

Astronomers dreamt up the idea

of Thorne-Żytkow objects —

dead stars inside dying stars — in

the 1970s. Only recently have

they tracked one down.

YVETTE CENDES

56

Eclipse of the

Super Moon

On September 27, the biggest

Full Moon of the year will pass

through Earth’s shadow.

DEAN REGAS

60

Astronomy’s sixth annual

Star Products

PHIL HARRINGTON

COLUMNS

Strange Universe 10

BOB BERMAN

For Your Consideration 14

JEFF HESTER

Secret Sky 18

STEPHEN JAMES O’MEARA

Observing Basics 22

GLENN CHAPLE

Astro Sketching 68

ERIKA RIX

QUANTUM GRAVITY

Snapshot 9

Astro News 12

IN EVERY ISSUE

From the Editor 6

Letters 10, 14, 22

Web Talk 26

New Products 69

Advertiser Index 70

Reader Gallery 72

Breakthrough 74

FEATURES

Astronomy (ISSN 0091-6358, USPS 531-350) is pub-
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SEPTEMBER 2015

VOL. 43, NO. 9

Dave’s

Universe

The inside

scoop from

the editor

Trips & Tours

Travel the

world with the

staff of

Astronomy

Weekly

Podcast

Observing

targets for all

skywatchers

50 Weirdest

Objects

Explore the

most curious

cosmic oddities

ONLINE

FAVORITES

Go to http://www.Astronomy.com

for info on the biggest news and

observing events, stunning photos,

informative videos, and more.

Visit Astronomy.com/toc

for bonus material — it’s

exclusive to Astronomy

magazine subscribers.

44

ASTRONOMY:

ROEN KELLY

ON THE COVER

Is our cosmos just one bubble in

an infinite sea? Many cosmologists

believe in such a multiverse even

without physical evidence.

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