According to a professor at New York University, it may be responsible for asteroid strikes such as the one that wiped out the dinosaurs.
The Earth orbits the centre of the Milky Way galaxy once every 250 million years. Though our planet’s route is not straightforward, it is roughly predictable: approximately once every 30 million years, we stray through the crowded plane of our galaxy, the Galactic disc.
Now, Prof Michael Rampino at NYU’s Department of Biology has found that this 30-million-year cycle seems to coincide with several of the most extreme mass extinctions in history. These include the famous asteroid strike that wiped out the non-flying dinosaurs some 66 million years ago.
So what could be causing this link? Rampino thinks that the answer might be dark matter – the invisible form of matter that concentrates in the Galactic disc, and that’s thought to make up over 80 per cent of all the matter in the Universe.
Rampino proposes that the gravitational force of dark matter could throw nearby extraterrestrial objects into our path as we enter the Galactic disc, meaning that comets and asteroids that would normally be far away are flung towards the Earth.
Perhaps even more astonishingly, Prof Rampino believes that this dark matter could also directly affect events on our planet. He has hypothesised that every time the Earth enters this plane, dark matter particles are drawn in by its gravitational pull, accumulating within our planet’s core.
Over time, he suggests, these subatomic particles interact with each other, releasing energy in the form of heat. This extra heat could help trigger geological upheavals such as volcanic eruptions, mountain building and changes in sea level, which also tend to peak every 30 million years.
Rampino hopes that his model will help scientists to better understand geological events on Earth, as well as some of the largest extinctions in history.