I've been wondering recently why pretty much all (if not all) of the exoplanets discovered- including the large amount of recently discovered exoplanets by the Kepler telescope- are larger than the Earth and much larger than smaller planets in our solar system such as Mercury and Mars. Do the laws of physics favour the formation of larger planets from the disc of matter that originally surrounds a star? Or have we just not found smaller planets yet for the very reason that they're small and don't exert a large gravitational wobble upon their parent star?
I'm just interested to find out the reason to why only large exoplanets (especially those such as Wasp-12B [I think that's what it's called]) have been found.
Thanks...