There"s a good chance the occupants of that car you can see in this photo, winding along a remote highway in the Highlands of Iceland, won"t encounter any other visitors to this desolate region. Accessible only during the summertime, roads across the Icelandic Highlands pass through mostly uninhabited volcanic desert. Frequent volcanic activity in the area creates a porous topsoil full of chemical compounds that aren"t conducive to plant growth. Besides, much of the rainfall is quickly absorbed so plant life only appears alongside glacial rivers. Despite this seemingly unwelcoming environment, adventurous travelers come to the Highlands every summer to see firsthand an ecosystem so unearthly that NASA conducted training missions here for some of its Apollo astronauts.