▁old . ▁▁ ▁The ▁lect ures hip ▁and ▁c ash ▁prize ▁are ▁awarded ▁every ▁eigh teen ▁months ▁to ▁an ▁individual ▁or ▁group ▁who , ▁by ▁his ▁or ▁her ▁passion ▁for ▁research ▁and ▁dedic ation ▁to ▁excell ence , ▁has ▁produced ▁a ▁body ▁of ▁work ▁in ▁observ ational ▁astronom y ▁which ▁has ▁resulted ▁in ▁a ▁significant ▁deep ening ▁of ▁our ▁understanding ▁of ▁the ▁universe . ▁Any ▁living ▁scient ist ▁is ▁el ig ible ▁for ▁this ▁award ▁without ▁consideration ▁of ▁race , ▁sex , ▁or ▁national ity . ▁Four teen ▁previous ▁A ar ons on ▁Prize ▁w inners ▁are ▁returning ▁to ▁T uc son ▁on ▁A pr ▁ 3 – 4 , ▁ 2 0 1 7 , ▁for ▁a ▁scientific ▁sym pos ium ▁in ▁Marc ' s ▁honor . ▁ ▁A ar ons on ▁came ▁to ▁Ste ward ▁Observ atory ▁as ▁a ▁post doc ▁after ▁receiving ▁his ▁Ph D ▁degree ▁from ▁Harvard ▁in ▁ 1 9 7 7 ▁and ▁became ▁an ▁Associ ate ▁Professor ▁in ▁ 1 9 8 3 . ▁His ▁astronom ical ▁research ▁focused ▁on ▁many ▁of ▁the ▁most ▁important ▁problems ▁of ▁observ ational ▁cosm ology : ▁the ▁cos mic ▁distance ▁scale , ▁the ▁age ▁of ▁the ▁Un iverse , ▁the ▁large - scale ▁motion ▁of ▁matter , ▁and ▁the ▁distribution ▁of ▁invisible ▁mass ▁in ▁the ▁Un iverse . ▁A ar ons on ▁made ▁important ▁contributions ▁to ▁the ▁understanding ▁of ▁stell ar ▁populations ▁in ▁the ▁Lar ge ▁Mag ellan ic ▁Cloud . ▁In ▁recognition ▁of ▁his ▁research ▁achiev ements , ▁A ar