NASA's Voyager 2 spacecraft gave humanity its first glimpse of Neptune and its moon Triton in the summer of 1989. This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera on Aug. 20, 1989. NASA hide caption

toggle caption

This artist's impression shows the surroundings of a supermassive black hole, typical of that found at the heart of many galaxies. The black hole itself is surrounded by a brilliant accretion disc of very hot, infalling material and, further out, a dusty torus. There are also often high-speed jets of material ejected at the black hole's poles that can extend huge distances into space. L. Calçada/ESO hide caption

toggle caption
L. Calçada/ESO

This artist's view shows an exoplanet orbiting the young star Beta Pictoris. The exoplanet has an eight-hour day — and a much faster rotation than any planet in the solar system. L. Calçada/N. Risinger/ESO hide caption

toggle caption
L. Calçada/N. Risinger/ESO

Taking Stock In The Search For Aliens

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript