Solar Systems Like Ours Are Likely To Be Rare

KentuckyFC writes "Astronomers have discovered some 250 planetary systems beyond our own, many of them with curious properties. In particular, our theories of planet formation are challenged by 'hot Jupiters,' gas giants that orbit close to their parent stars. Current thinking is that gas giants can only form far away from stars because gas and dust simply gets blown away from the inner regions. Now astronomers have used computer simulations of the way planetary systems form to understand what is going on (abstract). It looks as if gas giants often form a long way from stars and then migrate inwards. That has implications for us: a migrating gas giant sweeps away all in its path, including rocky planets in the habitable zone. And that means that solar systems like ours are likely to be rare."

Comments

Rare?

[east coast]

I didn't RTFA, but I will when I get home.

But on the surface it seems more to me that they're just saying that solar systems have a life cycle that is marked by the location of gas giants. I don't really think that means that our setup is rare.

But if I am misinterpreting the blurb and that is what they're proposing I would still say we need to hold our horses on any real judgement. We've found these solar systems because our current method of seeking these solar systems out is going to be more likely to find this kind of activity as opposed to what we have here at home. I think we're jumping the gun a bit on this one. I say let them work it out for a couple of more decades and even then we should be a bit more cautious about such sweeping statements.

Re:Rare?

[shma]

The parent is correct that there is a selection bias in our detection methods of planets that favours systems with gas giants close to the sun. However, this has nothing to do with the conclusions of the article. What they are saying is that, initially, the discovery of so many closely orbiting gas giants was confusing given that their models of planet formation show gas giants developing far away from the sun. What they have found through simulations is that gas giants naturally migrate inwards as the solar system evolves. So a 4 billion year old system like ours with gas giants far from the sun in unlikely. This conclusion comes from the simulations of solar system evolution, not from the observational data.