[Pearls Before Swine]

Isn't it harder to observe and detect solar systems like ours at interstellar distances precisely because the planets are so small?

[Deek]

My lay read of this (I are no astronomer), is that the technique used to look for planets around other suns is by looking for "wobble" in the star.

That approach make it much more likely to find stars with large planets in close, as the larger/closer the planet the more "wobble".

[BlazingArizona]

Isn't it harder to observe and detect solar systems like ours at interstellar distances precisely because the planets are so small?

Exactly! We detect extrasolar planets by watching for stars that wobble slightly because of the nearby presence of something massive. Only very large planets can do that. We can't draw any conclusions about extrasolar planets until we have the ability to see smaller planets.

[jpsb]

Yes but one can determine the distance the gas giants orbit theirs suns. Seems there is a narrow range in orbits that would permit liquid water and if a giant gas planet is in or near that range then an earth like planet could not be there too. And that assumes circular orbits, if any gas giant has an elliptical orbit then once again an earth like planet can not exist.

[SunkenCiv]

bingo.