2020-05-01_Astronomy

4 ASTRONOMY • MAY 2020

20
Is the Big Bang in crisis?
Stubborn problems with
dark matter, dark energy,
and cosmic expansion have
some astronomers rethinking
what we know about the early
universe. DAN HOOPER

30
V.M. Slipher’s
expanding universe
The Lowell Observatory
astronomer’s revolutionary
findings include the expansion
of the universe and the
discovery of the interstellar
medium. DAVID J. EICHER

36
Sky This Month
Venus meets Mercury.
MARTIN RATCLIFFE AND
ALISTER LING

38

Star Dome and

Paths of the Planets

RICHARD TALCOTT;

ILLUSTRATIONS BY ROEN KELLY

44

Cosmic clouds 3D

A glimpse behind the dusty

veil of nebulae reveals the

chemistry of the universe.

DAVID J. EICHER AND BRIAN MAY;

STEREO IMAGES BY

J.-P. METSÄVAINIO

52

Charting the

19th-century heavens

Schools and colleges

throughout America regarded

The Geography of the Heavens

as a valuable tool for teaching

astronomy. MICHAEL E. BAKICH

56

Target edge-on and

face-on galaxies

Hunting pins and needles in

the deep sky will give your

observing some pizzazz.

STEPHEN JAMES O’MEARA

62

We test Canon’s new

astrocamera

With 30 megapixels of

resolution, a full-frame sensor,

and a mirrorless body, the EOS

Ra camera can help you reveal

the night sky in all its glory.

TONY HALLAS

68

Ask Astro

Stellar collisions. IN EVERY ISSUE

From the Editor 6

Astro Letters 8

Advertiser Index 65

New Products 67

Reader Gallery 70

Breakthrough 74

FEATURES

MAY 2020

VOL. 48, NO. 5

Astronomy (ISSN 0091-6358, USPS 531-350)

is published monthly by Kalmbach Media

Co., 21027 Crossroads Circle, P. O. Box 1612,

Waukesha, WI 53187–1612. Periodicals postage

paid at Waukesha, WI, and additional offices.

POSTMASTER: Send address changes to

Astronomy, PO Box 8520, Big Sandy, TX 75755.

Canada Publication Mail Agreement #40010760.

Go to http://www.Astronomy.com

for info on the biggest news and

observing events, stunning photos,

informative videos, and more.

ONLINE

FAVORITES

9

QUANTUM GRAVITY

Everything you need to

know about the universe

this month: an asteroid-

strike crater found, a

second repeating FRB

tracked, new astronauts

introduced, and more.

COLUMNS

Strange Universe 16

BOB BERMAN

For Your Consideration 18

JEFF HESTER

Observing Basics 64

GLENN CHAPLE

Binocular Universe 66

PHIL HARRINGTON

CONTENTS 44

ON THE COVER

Some 13.8 billion years ago, the

Big Bang commenced a process

that filled the universe with

galaxies like M31. But we’re still

trying to determime how it all

happened. TONY HALLAS

Picture of

the Day

Gorgeous

photos from

our readers.

My Science

Shop

Perfect gifts for

your favorite

science geeks.

Trips and

Tours

Travel with

the staff of

Astronomy.

Sky This

Week

A daily digest

of celestial

events.

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