Originally posted by sonhouse
http://www.physorg.com/news137337086.html
This study shows how different our solar system is compared to the 300 planets around a lot of stars nearby, they are nothing like the jewel that is our solar system and the absolute jewel that is the Earth.
There are two statistical reasons why those 300 planets would be unlikely to represent typical exoplanets:
1, the larger the exoplanet, the easier and more likely it is that we would detect it,
2, the closer the exoplanet is to the star it orbits, the easier and the more likely it is that we would detect it.
The two facts above would mean that 300 planets would be unlikely to represent typical exoplanets. Both the larger size of the exoplanets and the closer the exoplanet is to the star it orbits, the greater the wobble it would cause of the star it orbits, and, it is mainly through the wobble it would cause of the star it orbits that these exoplanet are detected. That means those 300 planets would probably consist of planets that are both much larger and have much tighter orbits of the actual average exeplanet. Both excessively large and tighter orbits of large exoplanets would make the orbits of any Earth-size planets within the “inhabitable zone” unstable because of the gravitational effects of such large planets. If Jupiter was either 100 times larger than what it is or was closer to the sun than the Earth, it would make the Earths orbit so dangerously unstable that we probably wouldn’t be here. Thus extrapolating from those 300 planets by wrongly assuming that they are representative of typical exoplanets would give the false impression that the typical solar system is much less likely to be able to support stable-orbit Earth-size planets within the “inhabitable zone” than it actually is.