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 … Continue reading From Another Star
view more