The solar system, which is one of the planets, the Earth, was suitable for human life, it may be unique among the huge number of other planetary systems, which are in our Milky Way galaxy. Now scientists say that the planets in the Milky Way almost as many as there are stars. So far, scientists have found nearly 900 extrasolar planets outside the solar system, and thousands more are waiting to be discovered.
Thanks to modern technology of the distant planets and systems found in the last 15 years has significantly increased. Now, scientists can not even find the world of the moon. Analyzing the orbit, mass, diameter and composition of exoplanets, scientists have found that many planets are composed of gas, like Jupiter, and are from the star no further than Mercury is to the Sun.
Over the past 5 years, researchers have unexpectedly discovered the most common type of exoplanets that is not in the solar system — the size of a cross between Earth and Neptune. Such planets are much larger than the planets the size of Jupiter. "Sometimes they are called" super-Earth "- said study co-author Andrew Howard, an astronomer at the University of Hawaii.
Typically, these "super-Earth" more than our Earth in 1-3 times, and are much closer to its star.
The composition of exoplanet systems, researchers who study will help to better understand how planets are formed. According to one theory, the planet is born, when the gas is rapidly converted into the kernel. Another theory holds that the planet and its atmosphere are due to gravitational instability.
If you believe the theory of the growth of a nucleus around massive stars should be more large planets. In these stars should be enough elements heavier than helium, so that the ring around the star formed the nucleus of the future of the planet. While this theory is the closest to reality.
But much remains unknown about exoplanets, including the "super-Earths". "From what constitutes a" super-Earth "- asks Howard. — Whether they consist of the mountains? Are there water? Or are they, like Neptune, are composed of stone, water, and atmosphere composed of hydrogen and helium? '.
In addition, the emergence of such a "super-Earth" raises questions: whether it is in its place, or there is a different orbit and moved closer to the star?