Mars Volcano Apollinaris Patera . ... Credit Copyright: Malin Space Science Systems , MGS , JPL , NASA Explanation: Dwarfed by Olympus Mons and the other immense shield volcanos on Mars , Apollinaris Patera rises only 3 miles or so into the thin martian atmosphere, but bright water-ice clouds can be still be seen hovering around its summit. ... Like Apollinaris Patera, narrow furrows typically extend from their central craters or calderas . ... The large central crater is about 50 miles across. ...