As if Mayan “doomsday prophecies,” Sun-damaging planetary alignments, and fatal alignments with the galactic center were not enough, 2012 apocalypse proponents are also stating that on December 21, 2012, Earth will be hit by a huge asteroid that will cause mass extinction and global chaos.
As with the other 2012-doomsday scenarios, the asteroid strike claim has a good deal of scientific evidence against it. Of course, asteroids have hit our planet before – scientists believe a huge one (several miles wide) was probably responsible for the extinction of the dinosaurs – and it is virtually guaranteed that Earth will be hit again at some point in the future. But precisely because of that high probability, scientists around the globe are searching the skies for what they call “Near-Earth Objects” (NEOs) that may one day strike Earth.
NASA, in conjunction with several other astronomical organizations around the globe, has been cataloging NEOs since 1998. These organizations search the sky for asteroids and comets that are in Earth’s celestial neighborhood. When one is found, advanced computer programs model the object’s future path, taking into account the object’s size and speed as well as the influences of gravity from the Sun, Earth, and other planets and moons in our solar system. As the object comes closer, we can gather more information about it and further refine this model.
But why are scientists spending so much time searching for NEOs – it’s not like we could stop them from hitting Earth, right? It may sound like something out of a big-budget blockbuster, but astronomers actually do think that we would have a chance of deflecting a comet or asteroid headed for Earth – if we discovered it well enough in advance. Proposed methods for NEO deflection include solar sails, “gravity tractors,” and rockets – but NOT nuclear weapons as seen in Hollywood, which would only break the object apart and send deadly mini-asteroids our way. Russia has recently announced preliminary plans to deflect the asteroid Apophis (which technically has a chance of hitting us in 2036, albeit a very small chance).
So, could an asteroid strike the Earth on December 21, 2012? Sure – but a strike is no more likely on this particular date than on any other. Scientists in the NEO discovery program have not found any large object that is likely to even pass close to Earth on this date, or on any other in the near future. Even if they did, it is likely that we could deflect such an object before it intercepts Earth’s orbit.
Casey Rawson is the Science Content Developer for Science 360. She prefers "Deep Impact" over "Armageddon," if only for the escaping-a-tidal-wave-on-a-moped scene.