Astronomy

EARTH CHANGE The world’s best-selling astronomy magazine APRIL 2018 http://www.Astronomy.com Vol. 46 Issue 4 Secrets of nights ...

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For over 25 years, The Great Courses has brought the world’s foremost educators to millions who want to go deeper into the subje ...

CONTENTS Picture of the Day Gorgeous photos from our readers. News The latest updates from the science and the hobby. Ask Astro ...

WWW.ASTRONOMY.COM 5 The best $ eyepiece you’ll ever buy. No computer required. Battery- powered 7” color monitor included. High ...

Follow Astronomy http://www.twitter.com/ AstronomyMag http://www.facebook.com/ AstronomyMagazine plus.google.com/ +astronomymaga ...

WWW.ASTRONOMY.COM 7 Presented by Paddy Gilliland Rachel Freed David Lindemann Warren Keller Bob Stephens Gary Walker Dennis Cont ...

QG QUANTUM GRAVITY EVERYTHING YOU NEED TO KNOW ABOUT THE UNIVERSE THIS MONTH... 8 ASTRONOMY • APRIL 2018 SNAPSHOT The first inte ...

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10 ASTRONOMY • APRIL 2018 I f we’re ever to colonize other planets, we’ll have to deal with increased radia- tion environments. ...

ASTROLETTERS WWW.ASTRONOMY.COM 11 Shadow bands Mr. O’Meara, I was paging through the February 2018 issue of Astronomy maga- zine ...

ASTRONEWS 12 ASTRONOMY • APRIL 2018 FREE FALLING. A French satellite experiment confirmed that the equivalence principle — a key ...

ASTRONEWS Relative planet sizes are to scale, while distances are not. Kepler-90 system Kepler-90bKepler-90cKepler-90iKepler-90d ...

Relative number of galaxies ASTRONEWS 14 ASTRONOMY • APRIL 2018 Making sense of how galaxies are classified Elliptical galaxies ...

r-shaped Ellipticals Lenticulars Spirals Irregulars s-shaped Sa Sb Sc Sd A Normal B Barred ES s-shaped r-shaped A Normal B Barre ...

16 ASTRONOMY • APRIL 2018 W hat is the thinnest cres- cent Moon visible to the unaided eye during daylight? A good ques- tion, t ...

ASTRONEWS WWW.ASTRONOMY.COM 17 The first observed gravitational waves from the merger of two neu- tron stars was also the first ...

18 ASTRONOMY • APRIL 2018 T he most rewarding part of teaching intro astronomy was always introducing students to a differ- ent ...

ASTRONEWS Earth’s axial tilt 23.5° Jan. 2015July 2015Jan. 2016July 2016Jan. 2017July 2017Jan. 2018July 2018Jan. 2019July 2019Jan ...

ASTRONEWS 20 ASTRONOMY • APRIL 2018 RZ Piscium is a puzzling star 550 light-years away in the constellation Pisces. Astronomers ...