The mysterious dark matter that fills the entire universe could make devastating asteroids and comets fall onto the Earth, causing mass extinctions, including the one of mankind. American physicists claim to have found evidence for the correctness of this theory in craters on the surface of the Earth.
Lisa Randall and Matthew Reece from the University of Harvard, who made a related publication in the journal “Physical Review Letters“, believe that the threat is posed by a very dense disk of dark matter, located along the central plane of our galaxy and the thickness of which is about 35 light-years.
Our Sun, along with the Earth and the rest of the solar system, is continuously moving around the galactic center and at times crosses the disk of dark matter in its course.
When this happens, the gravitational effect of dark matter disturbs the orbits of comets and asteroids on the outskirts of the solar system, resulting in the fact that some of these celestial bodies are ‘thrown’ to its interior, where Earth is located. The likelihood of any of these comets and asteroids to strike our planet is very high.
The two American physicists believe that this is the cause of the fact that our planet is occasionally bombarded by falls of catastrophic celestial bodies, which leave a greater or lesser imprint in the form of craters.
Randall and Reece believe to have determined a “disaster cycle” lasting about 35 million years, which roughly matches the periodic ‘meeting’ of the Sun with the central galactic plane and the disk of dark matter.
The researchers analyzed craters on our planet with a diameter greater than 20 km and the age of over 250 million years, making a correlation with the cycle of 35 million years. They estimated that there the statistical probability that craters have been formed because of this cycle is three times greater than the probability that they have been randomly created.
The mission of the lander “Gaia” of the European Space Agency (ESA), launched in 2013, can give a definitive answer on whether there is indeed such a disk of dark matter in the center of our galaxy. The “Gaia” for the first time will create a detailed three-dimensional map of the stars of our galaxy, which will help reveal the invisible gravitational effect of dark matter.
Dark matter, which takes about four-fifths of all matter in the universe, surrounds galaxies and with the gravitational pull keeps them coherent, so as they don’t fall apart, despite the rapid rotation. The question is to what extent the dark matter is responsible for what happens inside the galaxies.