Seven football field–size caves may have been discovered on Mars. Analysis of photographs from NASA's Mars Odyssey orbiter revealed black spots near the massive Martian volcano Arsia Mons that do not look like impact craters because they lack blast patterns and raised rims. Scientists at Northern Arizona University and their colleagues say the possible caverns range from 330 to 825 feet wide and are 425 feet deep and have named them after their loved ones: Dena, Chloe, Wendy, Annie, Abbey, Nikki and Jeanne. Caves would serve as havens from radiation on the surface and so would be the most likely areas to harbor life. They could also accumulate ice, which could help to support future human exploration. NASA's Mars Reconnaissance Orbiter could take sidelong glances at the putative caves, a view that might show whether wider chambers exist underneath. The findings were unveiled during a March meeting of the Lunar and Planetary Science Conference in League City, Tex.