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Dark matter may be an asteroid toward Earth
Scientists from Harvard believe that dark matter may send catastrophic asteroid to Earth, causing mass extinctions, like the cataclysm that ended the age of dinosaurs.
As you know, according to physicists, the mysterious and invisible substance – dark matter – is five-sixths of all matter in the universe. First the influence of dark matter gravitationally manifested as it is (in theory) holds galaxies together, given the speed with which they are turned.
Not long ago, scientists assumed that the thin and dense disk of dark matter about 35 light-years away stretches along the central plane of the Milky Way. They suggest that the disk of gas and dark matter can disrupt orbits of comets outside the solar system, literally zashvyrnuv them inside, that is, to us. This can lead to disastrous consequences asteroid strikes the Earth, including such dimensions that led to the demise of the dinosaurs, says Lisa Randall and Matthew Rees of Harvard University.
One recent study suggests that meteorite bombardment of the Earth rises and falls in cycles for about 35 million years. Previously, scientists assumed that the cosmic trigger for this cycle is a potential companion star of our Sun – “Nemesis”. (Note that no Nemesis scientists have not yet found ).
Instead of blaming this “Death Star” in terrestrial catastrophes, Randall and Figure indicate that the judgment cycle corresponds approximately to the rate at which the Sun passes through the central plane of the Milky Way. Allusion is clear: the culprit may be the triumph of “the dark disk” in our galaxy.
Scientists estimate craters more than 20 kilometers wide, formed in the last 250 million years, and compared them with the schedule cycle of 35 million years. Subtotal: craters formed nearly three times more likely to correspond to the cycle of dark matter than chance.
Perhaps this cycle killed the dinosaurs about 67 million years ago.
“It is unlikely that this cycle is responsible for the mass extinction, but we have an incomplete set of data about craters, so perhaps the emergence of more information will allow us to better know about this hypothetical coincidence” – says Randall.
Although the chance of a three-to-one sounds impressive, the researchers caution that while statistics can not be trusted. Can help in this mission Gaia of the European Space Agency, which aims to confirm or deny the presence of disk dark matter. Launched in 2013, this mission will create accurate three-dimensional map of Milky Way stars and finally solve the riddle of the gravitational influence on the motion of stars.
“Even if quite a small chance that the dark matter may be exactly affect the local environment for long periods of time, it is worth examining,” – said Randall.
The detailed findings were published in the journal Physical Review Letters last week.
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Tags: Earth , meteorites , Dark Matter .
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