CREATE TABLE table_21085 ("Name" TEXT, "Latitude" TEXT, "Longitude" TEXT, "Diameter  ( km ) " TEXT, "Year named" FLOAT, "Name origin" TEXT)

What feature is at latitude 23.9S?
SELECT "Name" FROM table_21085 WHERE "Latitude" = '23.9S'
SELECT "Name" FROM "table_21085" WHERE "Latitude" = '23.9S'