What keeps Sphinx habitable.

phillies wrote:Vulcanism works. Deccan traps are an example. They shoved the air's CO2 content through the ceiling.

Somtaaw wrote:However Sphinx is orbiting a G0 star, while Sol is classified as G2, I think this means that Manticore-A is a little dimmer than our star.

Somtaaw wrote:Except Sphinx is actually on the cool side for a planet, not warm, and has particularly cold winters.

It's farther away from it's sun than Manticore, which is generally described much like Earth, which would make Sphinx almost Mars. Except our Mars has an orbital period of ~1.88 Earth years, while Sphinx is approximately 5 Earth years. Jupiter's orbit in Earth years is 12, so we can theorize if Earth = Manticore, then Sphinx would actually be approximately where our Asteroid Belt is, give or take a few thousand kilometers.

However Sphinx is orbiting a G0 star, while Sol is classified as G2, I think this means that Manticore-A is a little dimmer than our star. So Sphinx is orbiting farther away from a dimmer star (which is why it's such a cold planet), but Sphinx is heavier than Earth. This could lead to a thicker atmosphere, and yes slightly more greenhouse gases, which is why it's barely habitable.


Sounds perfectly plausible to me.

cthia wrote:I always thought Sphinx's orbital period is a huge part of her success. I initially found it difficult to account for her local flora. Sphinx has thicket trees and lush foliage. The kind of flora that needs lots of sunlight.

But then, with an orbital period of 5 yrs, gives lots of time during the best growing seasons to take hold, adapt and survive through natural selection. Sphinx is an example of life finding a way because it is given more than a reasonable chance to survive. Nature does the rest. I don't think it is a result of handwavium, but a result of the will of nature. Once local flora adapts and thrives, I can entertain the same eco system as we have here in the Congo, which supplies a rich contribution to our atmosphere. We don't know enough about native photosynthesis on Sphinx to venture too far out on a limb. We automatically project our baggage onto it. It could be that certain kinds of flora find Sphinx absolutely heaven. Flora can take hold anywhere. We simply assume that Earth's model is the meter stick.

Relax wrote:

TFLYTSNBN wrote:Just a bit of thought about why a planet with low instellation (spelling is correct) is habitable.
Weber writes about an active CO2 cycle which is not credible to any classically trained meteorologist.

I would suggest that Sphinx is warm because it has a thicker atmosphere with greater optical depth which results in the lapse rate being extended to an effectively lower altitude. Here is a discussion:

http://lasp.colorado.edu/~bagenal/3720/ ... EVM-5.html

Now that all the yes men ego boosters up thread have had their say...

To make Sphinx Habitable.....
DW wrote there is a very active volcanism which increases CO2... problem is it makes lots of high atmosphere DUST which BLOCKS the sun creating a very high albedo creating a VERY cold planet(dare I say, dead that far from the sun). Maybe we just say all of the vulcanism on SPHINX is all very THIN magma, so we get copious amounts of CO2 etc gases, but not giant cinder cone mountains which blow up(how on earth can we justify this? I have not put time to thinking on that subject).

Now to FIX this, we could say that said vulcanism is only in the oceans and that the oceans are VERY DEEP. We could also claim that the continents won't drift.... (Yea right) With very deep oceans + vulcanism all that heat keeps the oceans warmer than they should which correspondingly increases water vapor content in the atmosphere making for a very high heat retention capability of the planet as well as a deep atmosphere which also should create absolutely massive glaciation on a 6 year cycle, creating an extremely high albedo, but if the oceans were (non existent at the poles), but oblong at the equator with long and thin(broken up maybe?) to the northern/southern sections, circulation currents would be less leading to high hydrosphere, but the warmth of the equatorial oceans would not be sapped by the northern/southern polar ice sheets.

Since HIGH gravity on SPHINX, we need more abundant light gases for a DEEPER atmosphere for a better blanket for nap time on SPHINX. So, this pretty much equates to the need for much higher quantities of Methane, Helium, Argon than compared to earth and lower quantities of CO2. To get high Methane, Need large areas of tundra that over a 2 year summer would breath much more than earth? Methane out of an ocean = belching = mass die off events, but on a non moving tectonic world? Hrmm 100% of the oceans on Sphinx = at equator? Somehow I don't think it is possible to get high methane content without high corresponding CO2 percentage as well as one leads directly to the other... Maybe a bacteria which gets its energy from some type of algae in a symbiotic relationship since algae have chlorophyll allowing the bacteria to fix CO2 into CH4?

Water is the real greenhouse gas, not CO2, N2, O2 etc.

Just kinda reminiscing when reading about large planets 30 years ago and how it would be possible.

TFLYTSNBN wrote:The biggest factor would be a very thick atmosphere to insulate the surface. May about 20,000 kg per square meter verses Earth's 10,000 kg per square meter. This result s in the atmospheric lapse rate continuing to greater depth.

Thicker atmosphere also enables flight hence Honor Harrington's otherwise suicidal passion for hang gliding.

Relax wrote:

TFLYTSNBN wrote:The biggest factor would be a very thick atmosphere to insulate the surface. May about 20,000 kg per square meter verses Earth's 10,000 kg per square meter. This result s in the atmospheric lapse rate continuing to greater depth.

Thicker atmosphere also enables flight hence Honor Harrington's otherwise suicidal passion for hang gliding.

I have always thought DW missed an awesome short story with the heavy grav world and the need for a much denser atmosphere, the size of birds/bugs that could thrive on such a world. Oh my. 1 meter dragonflies.... Perydactls with 4 arms/2 wings.... we could have actually had....

Wait for it...
Wait for it...

A real live ....

Manticore....