Kirsten Siebach is pursuing her doctoral degree in geology at Caltech. She has been a member of the science teams on several recent Mars missions for NASA's Jet Propulsion Laboratory, including the Phoenix Lander, Mars Exploration Rovers (Spirit and Opportunity), and the Mars Science Laboratory (Curiosity).

The Map That Changed the World

In 1815, a surveyor named William Smith published a huge, 10-by-16-foot map of England, Wales, and part of Scotland titled A Delineation of the Strata of England and Wales. Up until then, explorers had sketched fairly accurate maps of land’s extent and contours. Smith’s hand-colored map indicated the geologic units … Continue reading