"This pit is certainly new to us," Cushing told the students. "And it is only the second one known to be associated with Pavonis Mons." He estimated the pit to be approximately 620 by 520 feet (190 by 160 meters) wide and 380 feet (115 meters) deep at least. The young researchers had initially set out to hunt for lava tubes, a common volcanic feature on Earth and Mars."The students developed a research project focused on finding the most common locations of lava tubes on Mars," Mitchell said. "Do they occur most often near the summit of a volcano, on its flanks, or the plains surrounding it?"