1) Impact crater on Mars 
Cavalry unit.
A cavalry troop. An operational section of an auxiliary cavalry ala, commanded by a decurio, whose size may have depended in turn on the size of its parent wing. If the turma consisted of 3 decuriae then it would have been comprised of 33 men. In an ala quingenaria the size of each turma was probably 32 cavalrymen, besides the troop commander, but …...