Triple system harbors closest black hole to Earth - Zoom-in video

Triple system HR 6819 has 2 stars and an invisible black hole. The black hole is the closest known back hole to Earth. Credit; ESO/L. Calçada, Digitized Sky Survey 2, N. Risinger (skysurvey.org) / mash mix by Space.com s [Steve Spaleta](http://www.twitter.com/stevespaleta)