Phil Plait is an astronomer who spent ten years working on Hubble Space Telescope before realizing he enjoyed talking and writing about it more than actually doing it.
He writes the Bad Astronomy Blog for Slate magazine, where he keeps up with the latest news from around the Universe. A few years ago he became fascinated (some say obsessed) with ways the world could be destroyed by astronomical phenomena, and wrote a book all about them called “Death from the Skies!”
He’s frequently seen on television science documentaries enthusiastically describing various planetary apocalyptic scenarios like Earth being gobbled down by a black hole or fried by a titanic gamma-ray burst.
He does see the up side to the Universe as well, and loves nothing more than to share the beauty and joy of the cosmos. From craters on the Moon to glorious spiral galaxies to how we know the Universe is 13.82 billion years old, everything we can see and know is amazing, and one of the best things humans can do is try to understand it all.