Stephen Hawking discusses the "Breakthrough Starshot" space exploration initiative during a news conference Tuesday at One World Observatory in New York City. Bryan Bedder/Getty Images for Breakthrough Prize Foundation hide caption

toggle caption Bryan Bedder/Getty Images for Breakthrough Prize Foundation

Stephen Hawking's Plan For Interstellar Travel Has Some Earthly Obstacles

  • Download
  • <iframe src="https://www.npr.org/player/embed/474227319/474235604" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">

An image from the European Southern Observatory shows the sky around the bright star Alpha Centauri — which appears so large because of the telescope optics and photographic emulsion — taken from photos in the Digitized Sky Survey 2. Alpha Centauri is the closest star system to Earth's solar system. ESO/Digitized Sky Survey 2/Davide De Martin hide caption

toggle caption ESO/Digitized Sky Survey 2/Davide De Martin