All_About_Space_-_Issue_94_2020

Scientistshavecomeupwitha newmeasurementfor

theexpansionrateoftheuniverse,leadingtoquestions

regardingthediscrepanciesbetweencurrentobservations

andthemodeloftheuniversethatastronomershave

reliedonforyears.Newobservationsmadeusingthe

HubbleSpaceTelescopeindicatethattheuniverseis

expandingattherateofjustunder 70 kilometres(

miles)persecondpermegaparsec,a distanceequivalentto

3.26millionlightyears.

Thisexpansionrateisslightlyslowerthanprevious

measurementstakenbyHubbleandtheEuropeanSpace

Agency's(ESA)Gaiasatellite,whichindicatedthatthe

universeisexpandingat73.5kilometres(45.6miles)per

secondpermegaparsec.Anotherearliermeasurementby

theESA'sPlancksatellitehasshownthattheuniverse

isexpandingata slightlyslowerrateof67.4kilometres

(41.6miles)persecondpermegaparsec.

Tomeasuretheuniverse'sexpansionrate– theHubble

constant– astronomerstypicallylookatstarsandgalaxies

toseehowfasttheyseemtobemovingapart.ThePlanck

measurement,however,isbasedonthecosmicmicrowave

background.Bylookingfor‘echoes’oftheBigBang,Planck

providedcluesaboutwhattheuniverselookedlikein

itsinfancyandenabledpredictionsofhowtheuniverse

wouldhaveevolvedtoreachitscurrentexpansionrate.

"Thisnewevidencesuggeststhatthejuryisstillouton

whetherthereisanimmediateandcompellingreasonto

believethatthereissomethingfundamentallyf lawedin

ourcurrentmodeloftheuniverse,"WendyFreedman,a

professorofcosmologyattheUniversityofChicago,said.

New Hubble constant stokes

mystery of universe’s expansion

Hundredsofprotesters,includingnative

Hawaiiancommunitymembers,theirelders

(kupuna)andothershavebeengatheringonthe

roadleadingtothesummitofMaunaKeaon

Hawaii'sBigIslandtochallengetheadditionof

anothertelescopicfacilitytothemountainthat

issacredtomanyontheisland.

Thegrouphasbeensituatedatthebaseof

themountainsince 15 July,whenconstruction

gearwasfirstscheduledtobeginarrivingfor

the$1.4billionThirtyMeterTelescope(TMT)

project,accordingtotheAssociatedPress.

Therewereabout 500 peoplegatheredat

MaunaKeaonMonday,accordingtothe

HonoluluStar-Advertiser.

UnarmedNationalGuardunitshavebeen

onthescenesinceMonday;arrestsbeganon

themorningof 17 Julymorningandcontinued

infrontofa crowdthathadgrownto2,

people,accordingtotheAP.TheAPadded

thatastronomerstookactivetelescopeson

themountainoff lineon 16 Julybecauseof

inconsistentstaffaccesstothesite.

MaunaKea,whichremainsa placeofprayer

tothisday,isaninactivevolcanothatrises

4,205metres(13,796feet)abovesealevel.

Protests continue againstconstruction

of Hawaiian telescope WordsbyDorisElinSalazar

©

TMT

International

Observatory

©NASA/ESA

An artist's

impression

ofthe Thirty

Meter

Telescope

(TMT)

Hubble peers

back in time

tothe furthest

galaxies

Its base lies under the Pacific Ocean, and if

measured from bottom to top, Mauna Kea

outshines Mount Everest as the tallest mountain

on the planet.

The debate about the TMT began when project

officials  selected Mauna Kea  as its site in 2009.

Telescope officials say the TMT is valuable to

science because the next-generation facility has

the capacity to peer deeper into space and farther

back in time than existing instrumentation,

taking imagery several-times sharper than what

the Hubble Space Telescope can see.

Words by Passant Rabie

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