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 ...

Throughout the year, as Earth progresses through its orbit around the sun, one can witness stars in the night sky rise and set at different times. It’s an example of an astronomical cycle visible to ...

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