Watch: Neil deGrasse Tyson reacts to Elon Musk's tweet about colonizing Mars Latest News News Watch: Neil deGrasse Tyson reacts to Elon Musk's tweet about colonizing Mars https://ift.tt/FKepBZ9 Astrophysicist Neil deGrasse Tyson joins CNN to react to Elon Musk's tweet about colonizing Mars. Hear what he thinks could be in our future.
