QUOTE (AlexBlackwell @ Mar 7 2006, 01:02 PM)
Correia and Laskar have
published some interesting work on this.
I've tried about six of those links, and they are all dead.
QUOTE (JRehling @ Mar 8 2006, 08:10 AM)
I've tried about six of those links, and they are all dead.
However, a summary/abstract appears here:
http://physicsweb.org/articles/news/05/6/6The low inclination and extremely low angular momentum always made impact-based explanations unlikely. It's pretty hard to smash things together and get things to balance out that neatly. C&L's work seems to conclude that from first principles, that with an atmosphere that thick, the planet's rotation is going to be driven by the atmosphere. Presumably (what the abstract/summary doesn't say), the huge thermal input from the Sun is another part of the story. Saturn, Uranus, and Neptune have bigger atmospheres, but they don't have daysides lit by a Sun measuring a full degree in the sky -- they have two+ orders of magnitude less solar input.
I don't know if anyone has ever looked at this angle, but with Grinspoon, et al, proposing that Venus may have lacked those bright clouds for much of its history, it may have formerly had particulalry large thermal tides if it had an albedo as low as, say, Mars or Earth's continents. If you imagine an atmosphere sticking out tens of km (?) farther on the dayside than the nightside, that's a lot of friction working against rotation.