“Thanks to the fact that the Earth isn't a perfect sphere, and invoking a bunch of Newtonian physics, you can deduce that our planet wobbles, too, taking roughly 26,000 years to trace out a small circle on the sky, a phenomenon known as precession.”

American astronomer and author

G. Seth Shostak is an American astronomer and author, best known as the senior astronomer for the SETI Institute. He has spent his career working in astronomy and public discussion of the search for life beyond Earth. His work at SETI places him at the center of research and outreach on extraterrestrial intelligence. As an author and scientist, he often writes and speaks about astronomy, the search for signals from other civilizations, and related questions about the universe.