Active galaxies pour out lots of energy. Active galaxies pour out lots of energy, due to their central supermassive black holes gobbling down matter. Galaxies tend not to be loners, but instead exist ...

Phil gives the course a send off with a look at some of his favorite topics. Here it is, folks: the end. In our final episode of Crash Course Astronomy, Phil gives the course a send off with a look at ...

For this week’s Crash Course Astronomy episode, we take a skidding halt at the edge of the planetary solar system and scream back inward to the vast space between Mars and Jupiter. Before I go on, I ...

Hank squares off against Crash Course Astronomy host Phil Plait in our special Valentine’s/Old Timey Medicine edition of ...