Neil deGrasse Tyson, your own personal astrophysicist, answers your questions about dark matter, black holes, light, time, relativity and the fabric of our universe in your favorite Cosmic Queries episodes of Season 4.
Dark matter is the longest unsolved problem in astrophysics. Find out what we know – and what we don’t – from your own personal astrophysicist, Neil deGrasse Tyson.