BBC Focus - 04.2020_

ASTRONOMY FOR BEGINNERS

orbitaroundus.A supermoon

canbeupto 14 percentbigger

and 30 percentbrighterthana

normalfullmoon.Technically,a

newmooncanalsobea

supermoon,butwedon’ttendto

markthesebecausewecan’tsee

them!Thenextfullmoon

supermoonafterthesewillbe in

April2021.

Supermoonsarea great

opportunitytostudythesurface

ofournaturalsatellitewith

binoculars.Thebesttimetodo

thisis actuallynotonthenight

ofthefullmoonitself,asit can

betoobright.Instead,picka

nighta fewdaysbeforeorafter

thefullmoontoseethemost

detail.Theeasiestfeaturesto

spotaretheMoon’scraters–

especiallytheyoungerones,

whichtendtobebrighter.You

should be able to see a large,

brightcraterjusttotheleftof

thecentreoftheMoon’ssurface.

Thisis Copernicus, whichis 93km

wideandthoughttobearound

800 millionyearsold(relatively

youngbytheMoon’sstandards).

If youimaginea lineof

symmetrydrawnvertically

throughtheMoon’sdisk,the

Apollo 11 landingsite,intheSea

o fTr a nquilli t y, is prettymuch

whereCopernicuswouldbe

reflectedontheotherside.

Youshouldalsobeabletosee

twomoredistinctivecraters

withyourbinoculars–

Aristarchus, whichis totheleft

ofCopernicus,andthehuge

Tychocraterattheverybottom.

If youlookcloselyenoughyou’ll

seetherearemanymore

craters,eachoneevidenceofthe

Moon’sbillionsofyearsof

meteorite bombardment.AB

LAURIEGUARD(AGE13),RUGBY

ISTHEREA FOURTH

DIMENSION?

We’refamiliarwiththree

dimensions,wherejustthree

numbersareenoughtopin

downourlocation:longitude,

latitudeandaltitude.We’re

alsosurroundedbythree-

dimensionalobjectsthatwe

describeusinglength,breadth

andheight.Forthousandsof

years,theexistenceofa fourth

dimensionwasdismissedas

ridiculous.Afterall,what

wouldit describe?

Butin themid-18thCentury,

theFrenchmathematician

Jeanle Rondd’Alembert

pointedoutthatthefourth

dimensioncouldbetime.This

suggestionwasonlytaken

seriouslyin the20thCentury,

whenAlbertEinsteinput

forwarda newdescriptionof

theUniversebasednotsimply

onlocation,butonevents,

eachdescribedbyfour

numbers:threeforwhere they

occur,andonefor

when.ThinkingoftheUniverse

asfour-dimensional

‘space-time’provedincredibly

powerful,andledtoa hostof

insightsabouthowthe

Universeandtheforcesat

workin it.Forexample,

accordingtoEinstein,gravityis

bestunderstoodasbeingthe

resultofthewarpingof

space-timebymatter.

Suchinsightshaveled

theoriststoinvestigatethe

ideaofmoredimensions– in

sometheories,asmanyassix

extradimensions,somehow

crumpleduptoosmallto

observedirectly.If true,these

theoriessuggestthathintsof

theextradimensionsmight

revealthemselvesasnew

subatomicparticlesatthe

LargeHadronCollider.Todate,

however,there’s no sign of

them.RM

HOW DOI

SEE THE

SUPERMOON?

WHEN:8 APRIL

AND 7 MAY 2020

Thisyear,AprilandMayare
especiallygoodmonthsfor
moongazers,becausewe
havetwosupermoonsina
row(threeif youcountthe
Marchsupermoon).
A fullmoon‘supermoon’
is definedasa fullmoon
thatcoincideswiththe
Moonbeingat(orwithin 90
percentof)itsclosestpoint
totheEarth(its‘perigee’)
as it follows its elliptical

Q&A

Tycho

Aristarchus Copernicus

NASA X4, GET T Y IMAGES ILLUSTRATION: DANIEL BRIGHT