Did the collision kick up a tremendous cloud of dust and debris which ultimately blocked out the sun? Or start a massive forest fire whose CO2 release literally cooked life to death? The latest hypothesis, according to a new paper in Geology, posits that the asteroid collided with Earth in the Gulf of Mexico, directly into a huge oil deposit. The fuel would have vaporized instantaneously, then caught fire in the atmosphere, sending a giant ball of flame around the planet. The evidence for the theory comes from the discovery of microscopic spheres of carbon in the K-T boundary. These droplets, known as cenospheres, are found only when hydrocarbons like oil are burnt. The spheres appear in eight of the thirteen excavated sites cited in the paper, and only in the K-T boundary. Whether the fire was solely responsible for the extinction is difficult to say; it is likely that a combination of factors were in play. This new development, however, could prove to be a key component in the whole picture. Via Science Now
