The search for the best observatory site in the world has lead to the discovery of what is thought to be the coldest, driest, calmest place on Earth — a place where no human is thought to have ever set foot. To search for the perfect site to take pictures of the heavens, a U.S.-Australian research team combined data from satellites, ground stations and climate models in a study to assess the many factors that affect astronomy — cloud cover, temperature, sky-brightness, water vapor, wind speeds and atmospheric turbulence. The researchers pinpointed a site, known simply as Ridge A, that...