Mysterious, bare patches of ground that polka-dot the deserts of Namibia and Australia are far more widespread than we knew. They're known as fairy circles, and a new global assessment has counted 263 sites where these bald spots can be found, spread across three continents and 15 countries, including Sahel, Madagascar, and Middle-West Asia. This new information could help scientists figure out what causes them, a question that is proving surprisingly tricky to answer. "We conducted a global and systematic assessment of fairy circle-like vegetation patterns and discovered hundreds of [fairy-circle]-like locations on three continents," write a team led by...