Will life on Mars go the way of the dinosaurs before we have a chance to discover it? Incoming Comet C213/A1, discovered on January 1st, is expected by some astronomers to pass within 28,000 miles of Marsin 2014. But cometary trajectories change, and an impact is not impossible, although NASA estimates that the object will pass Mars at a distance more like 80,000 miles.
Should it hit the planet, it will cause a spectacular explosion, releasing the equivalent energy of billion megatons of TNT. This is roughly the size of the blast that climaxed the extinction of the dinosaurs 65 million years ago.