Scientists who are engaged in space exploration, argue that in the vastness of the galaxy planets, which are very similar to Earth. In their opinion, exoplanets are divided into two types: super-earths and gas giants.
Scientists have determined that gas giants are most similar to the planet Neptune, and their size exceeds the size of the Earth by 3.5-4 times. Super-earths exceed the mass of our planet by a factor of 1.7. Astronomers are confident that in the vastness of the solar system there is no planet like Earth and other planets of our galaxy. But experts are confident that in other solar systems, which are not yet known to mankind, there are planets like our galaxy, there is an exact copy of the Earth.
The astronomer claims that our Earth is a special planet. All the planets of the stellar system can be classified by what kind of gangway characteristics, but our planet can not be attributed to any classification. This feature of our planet is studied by various specialists.