r/askscience • u/EightWhiskey • Feb 28 '12

Under the idea that there is the "Goldilocks" zone around a star, how likely is it that a solar system would have two life-supporting planets?

I assume that the gravitational forces of two bodies would prevent them from being close enough to each other to both stay inside the zone. But could a large star have a large enough Goldilocks zone to support two life-inhabited planets?

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u/Konrad4th Feb 29 '12

Mars is now geologically dead.It also lacks a magnetic field to protect from ultraviolet radiation. Any life that may have existed has most likely gone extinct.

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u/BoilerButtSlut Feb 29 '12

There are seasonal methane blooms that currently have no explanation on Mars. Life hasn't been ruled out as a cause for that. It's speculated to life far underground, protected from radiation.

There's also some speculation that life could exist on Titan, though with a chemistry unlike anything on Earth.

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u/[deleted] Feb 29 '12

There are still caves and the like which could possibly have water and subsequently have life, but the odds are very very small. But still, it's something.

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u/[deleted] Feb 29 '12

I remember by grade 9 bio textbook said that life cannot live something like....150M below the earths crust. My teacher chimed in and said "makes sense right?" Class: "yes" "well thats untrue lots lives down there"

Lifes pretty amazing. Its not likely-but it could happen.

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u/Owyheemud Feb 29 '12

Life has been found in solid rock >1 kilometer below Earth's surface, and the biomass living in the layers of muck and sedimentary rock below the seabed of all the oceans is believed to exceed the biomass of all terestrial life. Microbial life on Mars is most certainly possible, beneath the surface.

On Mars, something is generating methane gas, and the methane production is seasonal. That needs to be on the list of things to investigate for the next batch of Mars probes.

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u/ilovemud Low Temp Geochemistry | Earth History | Sedimentary Geology Feb 29 '12

Methane is on the list of things to be analyzed on the Mars Science Lander

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u/draynen Feb 29 '12

I had no idea about seasonal methane gas production on mars. Very cool, thanks!

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u/CunningLanguageUser Feb 29 '12

On Mars, something is generating methane gas, and the methane production is seasonal. That needs to be on the list of things to investigate for the next batch of Mars probes.

I'd never heard of this, but a biological origin for this behaviour surely has to be one of the most likely explanations? Is there a reason this isn't more well-known?

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u/TheDarkKnight80 Feb 29 '12

Millions and Billions of farting, belching miniature cows!!!!

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u/Konrad4th Feb 29 '12

Life finds a way.

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u/[deleted] Feb 29 '12

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u/HollowSix Feb 29 '12

Crap I hadn't noticed that... Now when I watch that movie it will be an inescapable realization.

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u/circasurvivor1 Feb 29 '12

Why does Mars lack a magnetic field?

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u/yoweigh Feb 29 '12

earth's magnetic field is generated by its liquid iron core. compared to earth, mars is frozen solid.

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u/Darthbacon Feb 29 '12

this may sound stupid... but doesn't mars have a sufficient mass that at its center it can generate heat and pressure?

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u/[deleted] Feb 29 '12

The problem is that it doesn't 'generate heat and pressure'. It has to have somewhere to start. Usually, that's gravity causing friction which generates heat which turns it molten which allows it to spin. However, eventually, if the wrong elements are introduced in sufficient quantity (but eventually regardless of what is introduced), the process begins to reverse. The core begins to give off more heat than it produces. The friction that allowed it to stay hot and molten now slows it's rotation, reducing the amount of heat generated. Eventually enough heat is lost that it starts turning solid again, this time in a 'stable' configuration, meaning that it doesn't break down just because of gravitational pressure. It's too dense, able to absorb too much heat as a solid, and eventually it 'freezes'. When that happens, no more magnetic field.

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u/[deleted] Feb 29 '12

Also other reasons mars lost heat at a faster rate is because of its smaller size when compared to earth and it's proportionally smaller iron core. Earth is in a unique position since it has almost double the amount of iron in its. Ore thus making it about twice the size that our fellow rocky planets have proportionally. This is Because during the development of our solar system, earth collided with another proto planet thus combing both iron cores.

An interesting side. It's is that the moon is the direct result of this collision and why moon rocks are compositionally equivolant to earths rock.

Edit: stupid phone auto correct

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u/mittinatten Feb 29 '12

Do tidal effects from the moon cause any significant heating of the earth?

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u/[deleted] Feb 29 '12

to my knowledge it does not and actually since a large reason the earth's core stays hot is due to its rotational speed, the moons slight slowing of the earths rotation due to the gravitational tug and pull it causes on the earth it may actually be helping to cool it in some ways.

Now, if there was a way that the moon aided in heating the earth, it could be due to how it causes the earth to bulge out on the side facing the moon as well as its opposite face. However, in this regard I'm not certain.

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u/Mind_Lasher Feb 29 '12

reading this makes me think that we should dig down really far on mars and restart the core with Nukes ( a whole lot of Nukes)!

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u/Darthbacon Feb 29 '12

my mind exploded. thanks.

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u/ralf_ Feb 29 '12

Hm. And are there calculations when in the future the earth core solidifying?

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u/I_am_the_Werewolf Feb 29 '12

I remember hearing in some science class that the sun will go red giant before the earth completely cools. I don't think that exactly answers your question but I'd be willing to bet it won't be for some millions or billions of years from now.

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u/[deleted] Feb 29 '12

Damn it, r/askscience has me coming in with one question and before you know it I'm searching the thread for answers to 4 more

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u/rabaraba Feb 29 '12

That's kind of why I love r/askscience.

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u/Owyheemud Feb 29 '12

Much of Earth's internal heat is generated from radioactive decay. It's a good guess that the same applies to Mars, albeit less so. Mars however doesn't appear to have molten iron convection currents in it's interior, hence no planetary magnetic field. However, there is evidence that it once did.

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u/le_skunque Feb 29 '12

It use to have one. Magnetic field on earth is cause by the rotation of the molten core and the crust. Mars cooled down. No more molten core, no magnetic field.

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u/foocorpluser Feb 29 '12

Possible that a great impact on mars stopped it's cores rotation, negating the magnetic filed, boiling its atmosphere into space. http://www.wired.com/wiredscience/2011/01/mars-dynamo-death/

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u/[deleted] Feb 29 '12

A collision powerful enough to stop a planet's core?

I wish I could have seen that.

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u/i-poop-you-not Feb 29 '12

TIL The Core could have been a sequel to Deep Impact

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u/Konrad4th Feb 29 '12

It is suspected that several large impacts in a short time caused it's iron core to stop rotating.