How Dark Matter Could Cause Mass Extinctions

The 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 on Earth, according to new research.
How Dark Matter Could Cause Mass Extinctions
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The 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 on Earth, according to new research.

In a new paper in Monthly Notices of the Royal Astronomical Society, New York University biology professor Michael Rampino concludes that movement through dark matter may perturb the orbits of comets and lead to additional heating in the 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. It is crowded with stars and clouds of gas and dust, and also a concentration of elusive dark matter—small subatomic particles that can be detected only by their gravitational effects.

Previous studies have shown that Earth rotates around the disc-shaped galaxy once every 250 million years. But the Earth’s path around the galaxy is wavy, with the sun and planets weaving through the crowded disc approximately every 30 million years.

Dark Matter Inside the Earth

Analyzing the pattern of the Earth’s passes through the galactic disc, Rampino noted that these disc passages seem to correlate with times of comet impacts and mass extinctions of life. The famous comet strike 66 million ago that led to the extinction of the dinosaurs is just one example.

What causes this correlation between Earth’s passes through the galactic disc, and the impacts and extinctions that seem to follow?

This artist's impression of the Milky Way Galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter. (L. Calçada/ESO)
This artist's impression of the Milky Way Galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter. L. Calçada/ESO