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

This appears to be a "When you are a hammer ..."

[SengirV]

"... Everything looks like a nail" situation to me. We've only really had the ability to discover LARGE planets around solar systems. Also, the shorter the orbit period, the easier it is to detect.

So logically, the planets we've found to date look NOTHING like those of our solar system. Jupiter's orbital period is 4332.71 days!!! And we are comparing that to the VAST majority of discovered planets(hot Jupiters) with orbital periods of less than 10 days?

Seems like this article belongs in the "Are US Voters Informed Enough About Science?" thread if you ask me.

Re:Rare?

[Hektor_Troy]

That's still rare. If we assume that there's 100 billion galaxies in the world (which Wiki says is the current estimate), and put a star system like ours on the rare end of the scale as in 1 per galaxy, you do end up with 100 billion star systems like ours. But that's still extremely rare, as it's pretty much impossible to find one.

Look at it another way: In 2006 the world supply of platinium was about 217,000 kg. That's about 1,112,341 mole or 667,404,810,235,590,822,414,959,709,663 molecules. That's a BIG number, but it's still a very rare metal. So rare in fact, that 2006 world supply wouldn't even let you give 1 gram of platinum to each resident of the United States.

Big numbers doesn't indicate how rare something is. Rare is an indication of the chance/risk of encountering something. And in a huge universe with 100 billion galaxies, 100 billion star systems like ours is RARE! In fact it's so rare, that it might as well not exist anywhere else, because without visiting other galaxies, we'd never know they were there.