American researchers have found that about once every hundred million years, the diameter of the heliosphere is somewhat smaller than the diameter of Earth’s orbit. As a result, our planet is vulnerable to the rays and interstellar dust, which can be caused by ice ages.
Scientists have built a computer model of the study of these changes heliosphere, that is the region where the solar wind moves at supersonic speed directly at our solar system passes through the galactic regions of different density. They managed to find a result that at a meeting with the dense dust clot diameter heliosphere may significantly decrease.
The Earth’s atmosphere as a result faces a cosmic rays and interstellar dust defenseless, they damage the ozone layer. Congestion in the upper atmosphere of dust leads to a decrease in the amount of solar heat that reaches the Earth’s surface, and, perhaps, to the appearance of the ice age.
Similar calculations, according to the researchers, who were held for red dwarfs, that is, for the most numerous class of well-known stars, show that these luminaries protect better the Sun’s own planet. So, for example, a planet in the area of suitable habitat for at such a star is not never outside the boundaries of her "the heliosphere." This is due to the fact that this area is closer in red dwarfs than in yellow and which is the Sun.
But this does not mean that red dwarfs for the existence of life is most suitable. A recent study, which was conducted by a team of astronomers at the University of Villanova, has found that orange dwarfs are the most likely, the most directly useful for finding planets around them, in which life and can not exist. It was found that red dwarfs emit often streams of charged particles that can not sustain life, in the usual sense.