Neil deGrasse Tyson on aliens, Mars colonization and 'UFOs' | Talking with Natasha #29

Astrophysicist Neil deGrasse Tyson joins Natasha Verma to unlock big cosmic questions with wit and clarity: Have aliens visited Earth? Will the universe ever stop expanding? Why does “Manhattanhenge” happen? And what’s inside his brand-new book, "Jus...