Sixteen seventh-graders at Evergreen Middle School in Cottonwood, Calif., found the Martian pit feature at the center of the superimposed red square in this image while participating in a program that enables students to use the camera on NASA's Mars Odyssey orbiter.

The feature, on the slope of an equatorial volcano named Pavonis Mons, appears to be a skylight in an underground lava tube. Similar "cave skylight" features have been found elsewhere on Mars (see http://www.jpl.nasa.gov/news/news.cfm?release=2007-106), but this is the first seen on this volcano.

The students in science teacher Dennis Mitchell's class were examining Martian lava tubes as their project in the Mars Student Imaging Program offered by NASA and Arizona State University. Students in this program develop a geological question, then target a Mars-orbiting camera to take an image that helps answer the question.

This is a subframe, about 8 kilometers (5 miles) wide, of an image that the Thermal Emission Imaging System (THEMIS) camera on Mars Odyssey took on April 7, 2010. The location on Mars is 0.5 degrees south latitude, 248.6 degrees east longitude.