A planet hunter powers down
After nearly a decade in orbit, more than half a million stars observed, and 2,662 planets discovered, the NASA space telescope Kepler has finally run out of fuel. Named after the 17th-century German astronomer Johannes Kepler, the probe was launched in 2009 to hunt for exoplanets— planets outside our solar system. It spent its first four years studying the same swath of space, during which time it helped astronomers establish that up to 50 percent of visible stars are likely have rocky, Earth-size planets that could potentially harbor alien life. After technical troubles forced engineers to alter Kepler’s mission, the telescope was tasked with examining new parts of the sky every few months. In total, the mission lasted twice as long as originally planned and dazzled astronomers with its finds, including worlds orbiting binary stars, inferno-like gas giants, and, last December, an eight-planet system. “Kepler has truly opened a new vista in astronomy,” William Borucki, a former mission leader, tells The New York Times. A planet-hunting Kepler replacement, the Transiting Exoplanet Survey Satellite, launched in April; another, the James Webb Space Telescope, is scheduled to go into orbit in 2021.
their risk of suffering a heart attack. Researchers looked at weather records and the medical data of 274,000 patients in Sweden between 1998 and 2013, reports The Guardian (U.K.), and found an increased incidence of heart attacks during periods with lower air temperature and air pressure, higher wind velocity, and fewer sunshine hours. The most pronounced link was with temperature; heart attack rates increased noticeably when the mercury dropped below 37 to 39 degrees Fahrenheit. The scientists suggested several possible factors: arteries narrowing because of the cold, people exercising less and eating more unhealthy foods on gloomy days, and the seasonal spread of infections. “We are very interested in the triggers of heart attacks,” says study leader David Erlinge, from Lund University. “If you know those triggers, you may be able to protect yourself.”
pole—the first time an animal has been recorded making a tool with more than two components. “The finding is remarkable because the crows received no assistance or training in making these combinations,” author Auguste von Bayern, from the Max Planck Institute for Ornithology in Seewiesen, Germany, tells ScienceDaily.com. “They figured it out by themselves.”