 Ida 's region 2 features several sets of grooves , most of which are 100 m ( 330 ft ) wide or less and up to 4 km ( 2 @.@ 5 mi ) long . They are located near , but are not connected with , the craters Mammoth , Lascaux , and Kartchner . Some grooves are related to major impact events , for example a set opposite Vienna Regio . 
