Friday, July 15, 2005
The view from Tatooine
Back in the 90's, astronomers thought they had a good idea of how planets formed. Planetary composition largely depended on the temperature of the disk of dust and gas where they started condensing. Close to the sun, where it was warm, planets would be rocky, further out, they would be icy. Gas giants could only form in the cold reaches of the protostellar disk where they could accumulate sufficient mass to hang onto massive amounts of gas. Reasonably sophisticated computer simulations based on these principles (well it is a bit more complicated than that really) produced solar systems similar to ours, rocky planets close, gas giants and icy world further out.
Then the first exoplanets were found. Massive, super Jovians screaming around their suns in orbits closer than Mercury's. These "hot Jupiters" destroyed our models. We've found solar system-like worlds recently, but the hot Jupiters need to be explained. Currently the best bet is that these planets form further out, then migrate in (incidentally ejecting or absorbing any terrestrial style planets in the way).
One thing that most people agreed on was that most multiple star systems would disrupt the protostellar disk so that planets would not be formed (or would so unstable they would be lost). Much to the disappointment of Starwars fans, Tatooine would not be possible. Now comes a report of a planet in a triple star system. This means we have to rethink the whole planetary formation idea again. Planets may be even more common than we thought, and Tatooine becomes possible again.
There is a great quicktime animation of an artists conception of sunset as seen from a hypothetical moon of the gas giant in this system.
Then the first exoplanets were found. Massive, super Jovians screaming around their suns in orbits closer than Mercury's. These "hot Jupiters" destroyed our models. We've found solar system-like worlds recently, but the hot Jupiters need to be explained. Currently the best bet is that these planets form further out, then migrate in (incidentally ejecting or absorbing any terrestrial style planets in the way).
One thing that most people agreed on was that most multiple star systems would disrupt the protostellar disk so that planets would not be formed (or would so unstable they would be lost). Much to the disappointment of Starwars fans, Tatooine would not be possible. Now comes a report of a planet in a triple star system. This means we have to rethink the whole planetary formation idea again. Planets may be even more common than we thought, and Tatooine becomes possible again.
There is a great quicktime animation of an artists conception of sunset as seen from a hypothetical moon of the gas giant in this system.
# posted by Ian Musgrave @ 11:46 am 
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