NASA’S office of planetary defense isn’t worried about Klingons or Amoeboid Zingatularians. 

They worry about asteroids and comets. 

Like the one that exploded over Chelyabinsk, Russia in 2013. It was about 20 yards across. An asteroid 150 yards in diameter could take out a city. An even bigger one — as the dinosaurs reading this will attest — could change earth’s ecology, and lead to mass extinctions.

Kelly Fast, program manager for NASA’s office of planetary defense, tells Dr. Michelle Thaller about an asteroid that watchers in Hawaii recently sighted:  a mysterious, massive, cigar-shaped object. 

Millions of years into its journey, it was traveling faster than any spacecraft ever built by humans. It’s the first object ever known to visit our solar system that originated in the orbit of another star. Too fast to be trapped by our sun’s gravity, it’s now traveling a path that will take it back into deep, interstellar space.



Orbital Path is produced by David Schulman. The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.



Illustration credit: ESO/M. Kornmesser