The Earth rotates around the disc-shaped Milky Way once every 250 years in a wavy path. An astronomer has noted that the rotations correlate to catastrophic events like mass extinctions and comet impacts - much like those that most likely caused the extinction of the dinosaurs 66 million years ago.
In a new paper published in Monthly Notices of the Royal Astronomical Society, New York University's Michael R. Rampino asks, "What causes this correlation between Earth's passes through the Galactic disc, and the impacts and extinctions that seem to follow?"
Rampino believes that the Earth's movement through dark matter causes a disruption in the orbit of comets and adds heat to the Earth's core - both phenomena that could send us the way of the dinosaurs.
Dark matter is invisible and can only be detected by the effects its gravitational pull has on other objects, according to a press release sent by the Royal Astronomical Society (RAS) on behalf of New York University, New York, N.Y.
As the Earth makes its 250-year voyage around the galaxy, the sun and planets have to dodge and weave to avoid crowding about every 30 million years. While the galaxy is stirring, dark matter bumps the orbits of comets that are usually far away from Earth, causing them to crash into the planet, according to Rampino's findings.
Also, with every pass through the disc, Rampino believes that dark matter can aggregate in the Earth's core. As the molecules gather, they "annihilate each other" and produce intense heat, according to the press release. The building heat could be the cause of volcano eruptions, the creation of mountains, magnetic field reversals and changes in sea level - all of which peak every 30 million years.
"We are fortunate enough to live on a planet that is ideal for the development of complex life," said Rampino, according to the press release. "But the history of the Earth is punctuated by large scale extinction events, some of which we struggle to explain. It may be that dark matter - the nature of which is still unclear but which makes up around a quarter of the universe - holds the answer. As well as being important on the largest scales, dark matter may have a direct influence on life on Earth."
