My first Magazine Sky & Telescope - 02.2019

CONTENTS THE ESSENTIAL GUIDE TO ASTRONOMY February 2019 VOL. 137, NO. 2 FEATURES Cover Story: 16 What Came Before the Big Bang? Cosmologists are tackling a once-verboten question with out-of-the-box thinking. By Faye Flam 84 Saturn’s largest moon has a remarkably complex atmosphere, with all the chemical ingredients for life as we know it. By Sarah Hörst 30 Above the Southern Horn of Taurus OBSERVING 41 February’s Sky at a Glance 42 Lunar Almanac & Sky Chart 43 Binocular Highlight By Mathew Wedel The Crab Nebula is amazing no matter how you look at it. 44 Planetary Almanac By Howard Banich 45 36 Explaining Algol How John Goodricke and Edward Pigott discovered and interpreted a new variable star. By Linda French 66 Giving Nebulae a Boost Here’s a novel technique to bring out emission nebulosity in your astrophotos. By Timothy Jensen Under the Stars By Fred Schaaf S&T TEST REPORT 58 Sky-Watcher AZ-GTi and Evostar 72 Refractor By Richard S. Wright, Jr. COLUMNS / DEPARTMENTS 4 Spectrum By Peter Tyson 6 From Our Readers 8 75, 50 & 25 Years Ago By Roger W. Sinnott 46 Sun, Moon & Planets By Fred Schaaf 10 News Notes 48 Celestial Calendar By S. N. Johnson-Roehr 57 Book Review By David Dickinson 52 Exploring the Moon By Charles A. Wood 64 New Product Showcase 54 70 Astronomer’s Workbench By Jerry Oltion Deep-Sky Wonders By Sue French 74 Gallery Find us on Facebook & Twitter ON THE COVER 84 Focal Point By Anna Barnacka ONLINE TIPS FOR BEGINNERS New to astronomy? From learning the night sky to tips on buying your ﬁ rst telescope, here’s everything you need to jump into the fun. skyandtelescope.com/letsgo Artist’s concept evok- ing string theory’s bubble universes PHOTO: TA K E 27 LTD / SCIENCE SOURCE 2 ASTRO TOURISM Come with us to explore wonders both on Earth and in the sky. See page 15 for current opportunities. skyandtelescope.com/ astronomy-travel ASTRONOMY Q&A From dark matter and black holes to comet observing and how to clean eyepieces, get your astronomy 101 questions answered. skyandtelescope.com/faq 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 (customer service/subscriptions), 888-253-0230 (product orders), 617-864-7360 (all other calls). Fax: 617-864-6117. Website: skyandtelescope.com. © 2019 F+W Media, Inc. All rights reserved. Periodicals postage paid at Boston, Massachusetts, and at additional mailing ofﬁ ces. 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. FE B RUA RY 2 019 • SK Y & TELESCOPE 22 Titan’s Veil

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