2019-07-01_Australian_Sky_&_Telescope

4 AUSTRALIAN SKY & TELESCOPE July 2019

REGULARS

5 Spectrum

6 Newsnotes

13 Discoveries

21 Newproductshowcase

FEATURES

14 Constantcontroversy

Astronomerscan’tagreeonthe

valueoftheHubbleconstant— the

numberthatdescribestheexpansion

rateoftheuniverse.A solutionis

nowhereinsight.

ByGovertSchilling

22 ThescienceofApollo

Rocksbroughtbackbytheastronauts

revolutionisedourunderstandingof

theMoon.

ByJohnA.Wood

28 ParkesandtheApollo 11

moonwalk

Australia’sveryown‘dish’played

a vitalroleinbringingthefirst

footstepsonanotherworldto

televisionscreensaroundtheglobe.

ByPeterRobertson

36 Lightinga cosmicfuse

TypeIa supernovae— thecosmic

milepoststhathelpedprovethe

universeis accelerating— arenot

asuniformasastronomersonce

thoughttheywere.

ByShannonHall

56 The allure of Betelgeuse

Astronomers are itching to know

when this red supergiant will go

supernova, but a clear answer eludes

them.

By Peter Tyson

Contents

July 2019 ISSUE 118, VOL.15 NO. 5

OBSERVING& EXPLORING

42 Binocular highlight

Open clusters in Centaurus

ByJonathanNally

44 Under the stars

The coloured stars of winter

ByFredSchaaf

46 Sun, Moon and planets

Saturn shines in Sagittarius

ByJonathanNally

47 Meteors

Duelling winter meteor showers

ByConStoitsis

48 Comets

Meet a very intriguing comet

ByDavidSeargent

49 Variable stars

Three target stars in Scorpius

By Alan Plummer

p.36 Solving the cosmic expansion conundrum

p.

What’s the mystery behind

this lunar landscape?

50 Exploring the Moon

Exploring a ghostly lunar feature

ByCharlesWood

52 Targets

Finding non-NGC star clusters

BySueFrench

55 Eclipse

Don’t miss July’s partial lunar eclipse

By Jonathan Nally