All About Space - UK (2020-02)

ININCOOPERATIONCOOPERATIONWITHWITH

NASA’s solar probe spots ‘stealth’

outburst on the Sun

Coronalmassejections(CMEs)aren’tknownfor

beingsubtle:eacheventcanf linghugeamountsof

thesoupofchargedparticlescalledplasmaoffthe

SunandoutintotheSolarSystem.InNovember

2018,asseenfromEarthandcertainspacecraft,

theSunseemedtobecalm...butitwasn’t.Itwas

experiencingwhatscientistscalla ‘stealth’coronal

massejection.Conveniently,NASA’sParkerSolar

Probewascompletingitsfirstclosepassbehindthe

Sunatthetime,puttingitsinstrumentsina perfect

positiontoseewhatwashappeningon 11 and 12

Novemberduringthisusuallycrypticevent.

“Ifyou’veeverseena CMEimage,younormally

seea lotofactivityintheseimages,”KellyKorreck,

a solarphysicistattheSmithsonianAstrophysical

Observatory,said.“Youwouldseea largeblowout;

youwouldprobablyseeoneoftheseexploding.But

therewasn’tmuchthere.”

EveninsomeoftheParkerSolarProbedata,it

wasn’tobviousatfirstwhatwashappeningduring

theincident,Korrecksaid.“Whenwelookedat

thisinitially– justthethermaldata– wedidn’t

necessarilythinkthattherewasa coronalmass

ejectionthere.”Butotherobservationstargeting

energeticparticlesdidincludethefingerprintofa

shock,a phenomenonthatusuallyaccompanies

a coronalmassejection.Scientistscouldalso

confirmtheprobewasflyingthrougha coronal

massejectionbasedondataitsinstrumentswere

gatheringaboutthemagneticfield.

Seeinga stealthcoronalmassejectionisa stepin

therightdirection.“They’resomethingthatwe’re

nottraditionallyabletoseeinthewaysthatwe’ve

previouslydetectedcoronalmassejections,”Korreck

said.“We’restartingtoseehintsofthemwithbetter

andbettertelescoperesolution.”

WordsbyMeg ha nBa r tels

Pluto’s heart

powers

icy winds

Words by M i ke Wa l l

The dwarf planet’s famous

heart-shaped feature, which

NASA’sNewHorizons

discoveredduringitsepic

July 2015 f lyby,drives

atmosphericcirculation

patternsonPluto.

Mostoftheactioncomes

courtesyoftheheart’sleft

lobe,a 1,000-kilometre(600-

mile)widenitrogen-iceplain

calledSputnikPlanitia.This

exoticicevaporisesduring

thedayandcondensesinto

iceagainatnight,causing

nitrogenwindstoblow.

Thesewindscarryheat,

particlesofhazeandgrains

oficewestward,stainingthe

icestherewithdarkstreaks.

“Thishighlightsthefact

thatPluto’satmosphereand

winds– evenifthedensity

oftheatmosphereisvery

low– canimpactthesurface,”

saidTanguyBertrand,an

astrophysicistandplanetary

scientistatNASA’sAmes

ResearchCenterinCalifornia.

Andthatwestward

directionisinteresting

initself,consideringthat

Plutospinseastwardon

itsaxis.Thedwarfplanet’s

atmospherethereforeexhibits

anodd‘retrorotation’.

Thisworkrevealedthe

likelypresenceofwesterly

winds– a high-altitude

varietythatracesalongat

leastfourkilometres(2.

miles)abovethesurfaceand

a fast-movingtypecloser

tothegroundthatfollows

Sputnik’swesternedge.

Stellar showdown spawns

spectacular rainbow cloud

WordsbySamanthaMathewson

UsingtheAtacamaLargeMillimeter/submillimeter

Array(ALMA),astronomersobservedthebinary

starsystemcalledHD101584,revealinga peculiar

gascloudthatisbelievedtobetheresultofa

confrontationbetweenthetwostars,accordingto

theEuropeanSouthernObservatory.

DatafromALMAandtheAtacamaPathfinder

EXperiment(APEX)showsthatoneofthestars

grewsolargethatitengulfedtheother.Asthe

smallerstarspiralledtowardsitsgiantstellar

companion,itcausedthelarger,Sun-likestarto

sheditsouterlayers,resultingintheexpanding

cloudsofgascapturedinthenewlyreleased

ALMAimages.

BasedontheALMAobservations,theresearchers

suggestthelow-masscompanionstarwascaptured

bytheredgiantstarwhenitreacheda criticalsize

onlya fewhundredyearsago.

Above:The

ParkerSolar

Probewasin

therightplace

attheright

timetospot

thissecretive

outburst

Left:Nitrogen

winds

havebeen

discovered

blowing

onPluto

Right:The

rainbow

resulted

froma binary

starmerger

© ALMA/ESO

© NASA

YOUR FIRST CONTACT WITH THE UNIVERSE

LAUNCH PAD

©NASA