Australian Sky & Telescope - April 2018

(avery) #1
20 AUSTRALIAN SKY & TELESCOPE April 2018

NASA’s next planet-hunting


mission will survey roughly


200,000 nearby stars for


signs of alien worlds.


L


ookingupatadarknightskywecanseethousandsof
stars.Everystarisasun,andifourSunhasplanets,
then it makes sense that the other stars would have
planets, too. And they do. Astronomers now know of
thousandsofthese‘exoplanets,’andtheysuspectthatnearly
everystarhasaplanetarysystem,meaningourMilkyWay
Galaxy is teeming with alien worlds.
ThankslargelytothepioneeringKeplerspacetelescope,we
alsonowknowthatsmall,rockyexoplanetsarecommonand
thatplanetarysystemsareastonishingintheirdiversity.
Butmanyofourexoplanetsearcheshavetargetedspecific
areasofsky.Thenaturalnextstepistodoaspace-based
all-skysurvey.Aspecificplanforjustsuchasurveymission
wasenvisionedadecadeagobymyMITcolleaguesGeorge
RickerandRolandVanderspek,incollaborationwithDavid
Latham at the Smithsonian Astrophysical Observatory. The
realisationofthismissionisthesoon-to-be-launchedNASA
Transiting Exoplanet Survey Satellite (TESS), which George
leadsasprincipalinvestigator(PI)andRolandasdeputyPI.
ThemotivationbehindTESSistofindplanetstransiting
starsrelativelynearEarth.Nearbystarsgenerallylook
brightertousthandistantones,andwithallthatadditional
lightreachingus,itwillbeeasierforustodetectthetinyblip

The Transiting


Exoplanet Hunter


TS


THE EXOPLANETS NEXT DOOR by Sara Seager
Free download pdf