Sky and Telescope - September 2018 - 2

CONTENTS

THE ESSENTIAL GUIDE TO ASTRONOMY

September 2018

VOL. 136, NO. 3

FEATURES

Cover Story:
14 Destination: Venus?
Our toxic twin might be a scientific
treasure-trove, but infrequent visits
are hindering studies, causing many
planetary scientists to grow
frustrated. By Shannon Hall

22 Near the Pit

41

30 The Enigma that Is
BL Lacertae
This cosmic detective story is still
ongoing today. By David Nakamoto

36 Polar Alignment with
Camera and Spreadsheet
Digital photography and a
computer spreadsheet offer a new
twist for precision polar alignment
of equatorial telescopes.
By Jürgen Kahlhöfer

62 Autumn in the Suburbs
The right telescope and a little
persistence will help you see these
subtle wonders. By Rod Mollise

41 September's Sky at a Glance
42 Lunar Almanac & Sky Chart
43 Binocular Highlight
By Mathew Wedel

45 Under the Stars
By Fred Schaaf
46 Sun, Moon & Planets
By Fred Schaaf

ESA / MPS / DLR / IDA / M.
PÉRE Z-AY ÚCA R & C. WILSON

2

68 RSpec Real-Time
Spectroscopy Software
By Rod Mollise
COLUMNS / DEPARTMENTS
4

Spectrum
By Peter Tyson

6

From Our Readers

7 75, 50 & 25 Years Ago
By Roger W. Sinnott
8 News Notes

48 Celestial Calendar
By S. N. Johnson-Roehr
52 Exploring the Solar System
By J. Kelly Beatty
55

Deep-Sky Wonders
By Sue French

12 Cosmic Relief
By David Grinspoon
72 Astronomer's Workbench
By Jerry Oltion
74 Gallery
83 Event Calendar
84 Focal Point
By Jerry Oltion

ONLINE

BEGINNERS' GUIDE
Print our free, 10-page handout to
distribute at star parties and other
community events. Includes charts!
skyandtelescope.com/
getting-started
ESA's Venus Express
orbiter took this ultraviolet view of Venus.

S&T TEST REPORT

44 Planetary Almanac

58 Going Deep
By Ken Hewitt-White

Find us on
Facebook & Twitter
ON THE COVER

OBSERVING

ASTRONOMY EVENTS
Add your upcoming star parties,
lectures, and more to our online
calendar, and find others near you.
skyandtelescope.com/
astronomy-events

SKY ON THE GO
Have an S&T guide in your pocket
with our skygazing apps: our weekly
SkyWeek tour and our JupiterMoons
and SaturnMoons.
skyandtelescope.com/Skyapps

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: 800-2530245 (customer service/subscriptions), 888-253-0230 (product orders), 617-864-7360 (all other calls). Fax: 617-864-6117. Website: skyandtelescope.com. ©2018 F+W Media, Inc.
All rights reserved. Periodicals postage paid at Boston, Massachusetts, and at additional mailing offices. Canada Post Publications Mail sales agreement #40029823. Canadian return
address: 2744 Edna St., Windsor, ON, Canada N8Y 1V2. Canadian GST Reg. #R128921855. POSTMASTER: Send address changes to Sky & Telescope, PO Box 420235, Palm Coast, FL
32142-0235. Printed in the USA.

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N ASA / ESA / STSCI

A bumfuzzling troupe of young stars
crowds around the Milky Way's
central black hole. How did they
get there, and what can they tell us
about gravity? By Camille M. Carlisle


http://www.skyandtelescope.com/getting-started http://www.skyandtelescope.com/astronomy-events http://www.skyandtelescope.com/Skyapps http://www.skyandtelescope.com/getting-started http://www.skyandtelescope.com/astronomy-events http://www.skyandtelescope.com

Table of Contents for the Digital Edition of Sky and Telescope - September 2018

Contents
Sky and Telescope - September 2018 - Cover1
Sky and Telescope - September 2018 - Cover2
Sky and Telescope - September 2018 - 1
Sky and Telescope - September 2018 - Contents
Sky and Telescope - September 2018 - 3
Sky and Telescope - September 2018 - 4
Sky and Telescope - September 2018 - 5
Sky and Telescope - September 2018 - 6
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