1 1 ° ▁S ., ▁ 3 1 . 5 ° ▁), ▁which ▁has ▁the ▁highest ▁al bed o ▁recorded ▁on ▁the ▁planet , ▁and ▁the ▁small ▁cr ater ▁Hun ▁Kal ▁( 0 . 6 ° ▁S ., ▁ 2 0 . 0 ° ▁), ▁which ▁is ▁the ▁principal ▁reference ▁point ▁for ▁Mercur ian ▁longitude ▁( D av ies ▁and ▁Bat son , ▁ 1 9 7 5 ). ▁Imp act ▁cr aters ▁and ▁bas ins , ▁their ▁numerous ▁secondary ▁cr aters , ▁and ▁heavily ▁to ▁light ly ▁cr ater ed ▁pla ins ▁are ▁the ▁characteristic ▁land forms ▁of ▁the ▁region . ▁At ▁least ▁six ▁mult iring ed ▁bas ins ▁r anging ▁from ▁ 1 5 0   km ▁to ▁ 4 4 0   km ▁in ▁diameter ▁are ▁present . ▁In asm uch ▁as ▁mult iring ed ▁bas ins ▁occur ▁widely ▁on ▁that ▁part ▁of ▁Mercur y ▁photograph ed ▁by ▁Mar iner ▁ 1 0 , ▁as ▁well ▁as ▁on ▁the ▁Moon ▁and ▁Mars , ▁they ▁offer ▁a ▁potentially ▁valuable ▁basis ▁for ▁comparison ▁between ▁these ▁planet ary ▁bodies . ▁ ▁Mar iner ▁ 1 0 ▁phot ography ▁▁ ▁Basic ▁information ▁about ▁the ▁planet ary ▁surface ▁of ▁the ▁K ui per ▁quad rangle ▁is ▁provided ▁by ▁three ▁sequences ▁of ▁high - quality ▁photograph s ▁designated ▁Mercur y ▁I , ▁II , ▁and ▁III , ▁obtained ▁during ▁the ▁incoming ▁phases ▁of ▁three ▁enc oun ters ▁of ▁the ▁Mar iner ▁ 1 0 ▁space craft ▁with ▁Mercur y . ▁Mercur y ▁I ▁includes ▁ 7