Celestia Forums

I was wondering, could Zecharias Sitchin and his cohorts at least be kinda right? I mean, one thing I noticed is that our solar system appears to be the exception, not the rule, as in most extrasolar planets are gas giants in the inner part of their star systems, and it is quite possible, in my opinion, that planetary migration occured in our star system's history, where the gas giants started in an inner orbit, but somehow wound up in an outer orbit, perhaps due to a large mass planet or brown dwarf in a highly elliptical orbit.

Any thoughts?

A disproportionately large proportion of detected planets are large and close to their stars because of an observational effect: large, close planets are easier to detect than small, distant planets. The primary method of detecting extrasolar planets is to observe the doppler shifts in the star's light due to its movement over the period of the planet's orbit. Large, close planets cause their stars to move faster than do small, distant planets, so their associated doppler shifts are larger and easier to detect.

That said, one of the theories explaining some extremely long period comets is that their might be a large body in the Oort cloud disturbing their orbits and causing them to fall into the inner solar system. There are other competing theories, however.

PlutonianEmpire wrote:one thing I noticed is that our solar system appears to be the exception, not the rule, as in most extrasolar planets are gas giants in the inner part of their star systems,

Keep in mind that radial velocity searches are biased in favor of finding such worlds. It's harder to find jovian planets in long period orbits, so when you start looking, you're going to find those planets in short orbits first.

I would have to agree with seldon. Larger planets on the top of the list of detection than smaller planets simply because of their size. Once we can see further into the cosmos than we can now then you will see that more of the smaller planets are being discovered.

Nick

well...

for more go to http://en.wikipedia.org/wiki/Nice_model