Part of the astronaut experience is seeing very many landscape and geology patterns, especially in deserts where vegetation is thin on the ground. A crew member aboard the International Space Station took this image of a circular hill in central Iran (image right). Even from 400 km up in space, this long-lens image shows details of the small (3.25 km long) flat hilltop. Numerous, multi-colored lines on the sides of the hill show that the hill is made of many thin layers of sedimentary rock. The neighboring dry lake has a white salt-covered surface. By contrast, the darkest areas are shrubby desert vegetation on the lowest slopes of the hill, the only zone where enough water concentrates to allow vegetation to grow.

The astronaut might even be able to tell the difference between the long curved lines on the left of the image. One is an ancient shoreline formed when the lake contained permanent water--with waves strong enough to shape sediments into the form of a smooth beach. Another curved, slightly irregular line is a harder rock layer sticking out of the desert floor.