American cosmologist Lisa Randall is suggesting that dark matter may have played a key role in the extinction of dinosaurs, according to Phys.org.
While the extinction that took place 66 million years ago was likely caused by a comet or asteroid colliding with the Earth, the low likelihood of these events occurring makes Randall believe that there's more to the story - something that could have increased the amount of comets at the time and thus make an asteroid or comet collision much more likely.
Randall believes that dark matter, which is an invisible type of matter that is approximately five times more common than normal matter and accounts for 85 percent of matter in the universe, may have been responsible, according to The Hamilton Spectator. She believes that a sweeping disk of dark matter may have flew past our solar system and, in the process, created a tiny perturbation in space that created a gravitational force that knocked comets out of the Kuiper belt, or the Oort cloud.
"We know it's out there. We have seen its gravitational effects in many different ways," Randall told CTV News. "In fact, billions of dark matter particles are passing through you this second and you don't know about it because they just aren't interacting with you."
Randall hopes that the Gaia satellite will shed light on her theory in its mission to measure the position and velocities of approximately 1 billion stars in order to create a three-dimensional map of the Milky Way.