Named after the Hindu god of destruction, the Shiva Hypothesis is a scientific theory that purports to explain an apparent pattern in mass extinctions caused by impact events. The theory, created by Michael Rampino of New York University, says that gravitational disturbances caused by the Earth crossing the plane of the Milky Way galaxy are enough to disturb comets in the Oort cloud surrounding the solar system. This sends comets in towards the inner solar system, which raises the chance of an impact. According to the hypothesis, this results in the Earth experiencing large impact events about every 30 million years (such as the Cretaceous-Tertiary extinction event). This theory has one worrying implication: as the solar system has passed through the galactic plane in the last few million years, another comet could be approaching Earth.
