Scientists who work for nuclear waste disposal projects in Finland, Canada and Sweden study an ice sheet in western Greenland. Courtesy of Vincent F. Ialenti hide caption

itoggle caption Courtesy of Vincent F. Ialenti

Will the distant future give rise to exhibits of a human past long gone, much as we gawk today at representations of a dinosaur age we can only imagine? Aamir Qureshi/AFP/Getty Images hide caption

itoggle caption Aamir Qureshi/AFP/Getty Images

Coprates Chasma in the Valles Marineris on Mars, photographed by the Mars Express spacecraft. Appearing in the top half of this image, it ranges from 60-100 km wide and drops 8-9 km below the surrounding plains. G. Neukum/ESA/DLR/FU Berlin hide caption

itoggle caption G. Neukum/ESA/DLR/FU Berlin