Science Tidbits #5

[RJDiogenes]

It's hard to tell how the tidal locking would affect the environment. The only tidally locked world we know about it Venus, and that has a runaway greenhouse effect. An Earth-like world with a transparent atmosphere and massive oceans may be better able to distribute the heat, although it would likely have monstrous winds. But that's why I wonder about the gas giant in the middle orbit. Given the great disparity in their masses and the frequent conjunctions, the giant's gravity may keep the planet spinning.

[Lupine]

Actually Venus isn't tidally locked, but it's rotation is very slow. Whether that has anything to due with its current condition is an open question.

[RJDiogenes]

Now it's not tidally locked? First Mercury was locked and Venus wasn't, and then it was the other way around. I just can't keep up.

I'd love to know if either the slow rotation (or tidal lock) or the lack of a satellite has anything to do with runaway greenhouse effect.

[Lupine]

It's actually rather hard to study planets closer to the sun than us. Venus especially since it's covered in clouds. The slow rotation and lack of a moon might play a role in it's current state. Personally I've wondered if it got hit by something big in the past, altering it's rotation.

[RJDiogenes]

Could be. That happened to us, so it could have happened to Venus, too, only with the opposite result.

[scottydog]

Doesn't having a nearby gas giant come in handy for steering comets and asteroids away? I think I heard somewhere that Jupiter serves this function for us.

[Lupine]

^Yeah that's one of the theories out there, along with it steering comets here to give us water. Sometimes both theories are lumped together. But I refer to those as "Miracle Theories"- IE, "We wouldn't be here except for (fill in the blank)".
The Jeans-Jefferys hypothesis was a variation of a Miracle Theory as was the notion that only singular stars (like the Sun, thus rare) could have planets.

[RJDiogenes]

Yeah, I find the Mediocrity Principle much more believable than Miracle Theories. I don't really buy into any theory that has Jupiter contributing heavily to life on Earth. I think there's a much more basic set of elements involved.

[Lupine]

And in the case of exo-planets the Mediocrity Principle has been borne out.

[RJDiogenes]

Yup, wherever dirtballs can clump together, they will.

[Lupine]

And ironically we have another article that takes a hot at Jupiter.

[RJDiogenes]

That's interesting, because I never knew there was such a demarcation and that the outer system was more rich in organics-- kind of ironic, since all the organic beings that we know of are down here. I wonder how, or if, things would be different if the inner system had also been rich in organics. Would life on Earth have evolved more quickly or more robustly? Would life have had a better chance on Mars or Venus, and shaped their environments differently? Very interesting.

[Lupine]

Apparently a second planet has been found orbit Proxima Centauri (they think)
However it does not look like a vacation spot.

[RJDiogenes]

^^ That link is dead, but it's even dead when I find it on Google, so they must have removed the page for some reason. Maybe the denizens of Proxima C don't want to be found!

Anyway, I did see it on CNN today. The headline said "Earthlike," but it didn't sound very Earthlike to me, although I can see that it has the potential to be life bearing. It's very interesting that both of Proxima's planets could have life of some kind. Makes for a very tempting target.

[Lupine]

Odd, because I just clicked the link and it worked.