Archaeologists have many tools at their disposal: shovels, trowels, satellites. If you are scratching your head at that final entry, check out how TED Prize winner Sarah Parcak uses satellite imagery to locate long-lost ancient sites, and to solve some of archaeology's most enduring mysteries.

Itj-tawy, once located on the bank of the Nile, was Egypt's capital for about 350 years during the period known as the Middle Kingdom. But sometime after 1785 BC, when the capital moved to Thebes, Itj-tawy disappeared. "Egyptologists knew the city had to be somewhere near the pyramids of the two kings who built it, but that only narrowed it down to an area about four miles by three miles in size," says Parcak. To pinpoint the city's exact location, Parcak's team used NASA topography data to map the floodplain area, and analyzed it for subtle changes in vegetation. They wanted to understand where the Nile used to flow — to the west of the river we know today. Using the ancient water line as a guide, they spotted a large raised area in the circle above.