The elusive dark matter may have been responsible for the comet strike that wiped out dinosaurs 65 million years ago, a new study suggests.
Research by New York University Biology Professor Michael Rampino concludes that Earth's infrequent but predictable path around and through our galaxy's disc may have a direct and significant effect on geological and biological phenomena occurring on Earth.
He concludes that movement through dark matter may perturb the orbits of comets and lead to additional heating in Earth's core, both of which could be connected with mass extinction events.
The Galactic disc is the region of the Milky Way Galaxy where our solar system resides.
Previous studies have shown that Earth rotates around the disc-shaped galaxy once every 250 million years.
But Earth's path around the galaxy is wavy, with the Sun and planets weaving through the crowded disc approximately every 30 million years.
Analysing the pattern of Earth's passes through the Galactic disc, Rampino notes that these disc passages seem to correlate with times of comet impacts and mass extinctions of life.
The famous comet strike 65 million ago that led to the extinction of the dinosaurs is just one example.
While travelling through the disc, the dark matter concentrated there disturbs the pathways of comets typically orbiting far from Earth in the outer solar system, Rampino noted.
This means that comets that would normally travel at great distances from Earth instead take unusual paths, causing some of them to collide with the planet, researchers said.
But even more remarkably, with each dip through the disc, the dark matter can apparently accumulate within Earth's core. Eventually, the dark matter particles annihilate each other, producing considerable heat.
The heat created by the annihilation of dark matter in Earth's core could trigger events such as volcanic eruptions, mountain building, magnetic field reversals, and changes in sea level, which also show peaks every 30 million years.
Rampino therefore suggests that astrophysical phenomena derived from Earth's winding path through the Galactic disc, and the consequent accumulation of dark matter in the planet's interior, can result in dramatic changes in Earth's geological and biological activity.
"The history of Earth is punctuated by large scale extinction events, some of which we struggle to explain," said Rampino.
"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," Rampino added.
The research was published in the journal Monthly Notices of the Royal Astronomical Society.