OSIRIS-REx and the Hayabusa spacecraft have sample asteroids to understand what they're made of. NASA sent the DART mission to change the orbit of a tiny asteroid orbiting another asteroid. ESA sent Hera as a follow-up mission to see what the impactor did. All of these missions have been done in the name of planetary defense -- protecting Earth from the worst of the rocks in space. While none of the asteroids so far discovered are a threat to our planet in the next century, there are still more out there that are small enough to do major damage to a city or even country. So what do we do if we find a near-Earth asteroid that's a real threat? Launch a team a la "Armageddon"? Ignore the problem? Try to flee off-planet or below ground? As DART showed, the best answer seems to be "move it out of the way". In his new book "How to Kill an Asteroid", Dr. Robin George Andrews tells the story of planetary defense and how we got to this point in saving ourselves. Join communications specialist Beth Johnson in a fun (and slightly scary) conversation with Dr. Andrews about killer asteroids this Halloween on SETI Live. (Recorded 31 October 2024.)