Post Reply Anyone Here Familair with Planetary Science/Astrophyisics?
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30 / M / In a world that d...
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Posted 10/4/15
I realize CR might be the wrong place for this, but I figured it couldn't hurt to check, even in General.

Anyone here familiar with planetary science, astronomy, or similar studies?

I got a question about what it might be like for a habitable zone world (specifically, around 85% away from the starting edge where many scientists agree that liquid water can exist under ideal air pressures) under certain conditions. I'm worldbuilding for a story I'm writing and I wanted to try some different things which have at least some scientific basis.

If I get a response I'll post more, realized a store I gotta hit is closing soon.
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Posted 10/4/15
You'll get better response on the forums at phys.org
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Hoosierville
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Posted 10/4/15 , edited 10/4/15
It would be similar to Earth during its ice ages. Permanent ice covering much of the northern and southern hemisphere. However what its like past that can vary wildly depending on if the planet has a tilt like Earth or spins in a perfect circle.

If its like Earth and tilts: The permanent glaciers would go down to thee bottom of Illinois normally, assuming a cooling event isn't in effect. Below that it would be southern Canada then slowly warm up till you hit the Equator which would not be as hot and dry as ours is right now. The Equator might get 80 degrees max but would typically be around 50-70 in the summer. Due to all the ice holding the worlds water sea levels would be much lower. It might be too cold fr jungles around the equator, could be some natures weird. The world would have many pine trees and more leafy trees close to the equator. Most animals would have thick fur for the long and cold winters. Winters would be very harsh for most of the world and would normally go into the negatives. Every fall migrations down south would happen for animals avoiding the harsh cold. Look up what its like from midcanada to Illinois and that will be your world but colder.
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Posted 10/4/15
Habitable zone is only part of the equation

Earth has frozen in the past, for example (look up Snowball Earth).

Atmospheric composition is huge. What would the surface temperature of Mars be if it had an atmosphere as dense as Venus'?
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23 / M / Abyss
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Posted 10/4/15 , edited 10/4/15
I am a geologist major with an elective of planetary science. If you have any questions, PM me and I will get to them in my free time. I will answer it to the best of my abilities.

Also, a world doesn't need water per-say to live. The air we breathe could be poisonous to others and the water could be the same. Seeing as Hydrogen and Oxygen are two of the most common elements in the Universe, water is actually fairly common. Look at Mars. Also, there are many Earth-like planets. Here are a few if you want to read up on them:

Kepler-69c
Kepler-9d
COROT-7Bb
Kepler-20f
Tau Ceti b
Alpha Centurion Bb
Kepler-186f
Kepler-20e

All of these have a habitable conditions. They are worth a read for your story if you have time!

Also, I will be out in the field from the 8th to the 11th of this week. If you message me then, I will try to get back to you around the 12th.

Edit for post above: Req's to be habitable.



Hope this helps!
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27 / M / Near a peach tree.
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Posted 10/4/15 , edited 10/8/15
Planetary Science/Astrophysics aren't my field of expertise, but I'd love to learn stuff about related to space from other people. I once heard that science rules.
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21 / Australia
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Posted 10/4/15
Is that the stuff with the planet things?
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F
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Posted 10/4/15 , edited 10/4/15
Could barely pass chem....
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13 / F / California
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Posted 10/4/15
Most people also agree that a liquid core that causes a magnetic field is good as well.
Posted 10/5/15
I think just create something from your imaginations. Because even in science, we don't really know what exactly is required for life to survive outside of Earth... do they really need water to survive?

___

Read up on something called "extremophiles". These are a group of microorganisms that can survive in very cold, or hot, very acidic or highly pressurised environments.
Remember, life adapt to the Earth's environment, not the Earth adapting to suit life forms. While our basic blocks consist of sulphur, nitrogen etc... life outside of Earth could have completely different elements in their genetic make up to adapt to the conditions on their planet.

The extremophiles that can live in very cold temperatures can't survive in very hot temperatures because their genetic material is suited for defense against coldness, not hotness.

I assume the more complex a life form is, the more stability they would need. Like us for example, we are like an orchid flower, needing stability more than something like bacteria for example.


When creating your world, think about how the pressure, temperature, gravity could affect how life could form. What about the amount of oxygen? Does your life form breathe oxygen? We know that oxygen isn't a requirement for life to thrive.
Posted 10/5/15
try Doctor Who, it'll give you a touch-up.
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Posted 10/5/15
RIP Pluto?
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30 / M / In a world that d...
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Posted 10/5/15

Rujikin wrote:

It would be similar to Earth during its ice ages. Permanent ice covering much of the northern and southern hemisphere. However what its like past that can vary wildly depending on if the planet has a tilt like Earth or spins in a perfect circle.

If its like Earth and tilts: The permanent glaciers would go down to thee bottom of Illinois normally, assuming a cooling event isn't in effect. Below that it would be southern Canada then slowly warm up till you hit the Equator which would not be as hot and dry as ours is right now. The Equator might get 80 degrees max but would typically be around 50-70 in the summer. Due to all the ice holding the worlds water sea levels would be much lower. It might be too cold fr jungles around the equator, could be some natures weird. The world would have many pine trees and more leafy trees close to the equator. Most animals would have thick fur for the long and cold winters. Winters would be very harsh for most of the world and would normally go into the negatives. Every fall migrations down south would happen for animals avoiding the harsh cold. Look up what its like from midcanada to Illinois and that will be your world but colder.


This is one possibility, but my estimates have put it more towards what some believe ancient Mars was like if it had the gravity, atmosphere and air pressure of Earth, but you have presented one possibility, yes.




GayAsianBoy wrote:

I think just create something from your imaginations. Because even in science, we don't really know what exactly is required for life to survive outside of Earth... do they really need water to survive?

___

Read up on something called "extremophiles". These are a group of microorganisms that can survive in very cold, or hot, very acidic or highly pressurised environments.
Remember, life adapt to the Earth's environment, not the Earth adapting to suit life forms. While our basic blocks consist of sulphur, nitrogen etc... life outside of Earth could have completely different elements in their genetic make up to adapt to the conditions on their planet.

The extremophiles that can live in very cold temperatures can't survive in very hot temperatures because their genetic material is suited for defense against coldness, not hotness.

I assume the more complex a life form is, the more stability they would need. Like us for example, we are like an orchid flower, needing stability more than something like bacteria for example.


When creating your world, think about how the pressure, temperature, gravity could affect how life could form. What about the amount of oxygen? Does your life form breathe oxygen? We know that oxygen isn't a requirement for life to thrive.


Considering the aim is human habitation, I am not building a planet for mostly extremophilic life. I already have all of the other factors in place - necessary air pressure, sufficiently strong magnetic field, geologic activity, proper size and gravity, and necessary amounts of water for a biologically diverse world capable of supporting humans, and a G or K class main sequence star of sufficient age - the basic defaults most fantasy worlds are built in with human habitation, but aren't Earth.

What I was more curious about were some more exotic combinations; a dual habitable planet binary system (on the scale of near 1:1 mass between both planets), an ocean moon around a habitable world (or a binary planet with an exotic moon system), or extreme axial tilt. Normally, I wouldn't worry about the science behind such matters as long as things were more plausible but considering I'm debating that certain portions of this story might take place in space, I figured I should at least cover my bases.
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49 / M / Planet KLK-X
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Posted 10/8/15
You can have the star of the system be hotter or cooler to suit your story and setting. For main sequence stars like our sun, the older they are, the hotter they burn. Gradually, over billions of years. So you can pick a point somewhere in the star's lifetime when the conditions on your planet(s) will be whatever you might like them to be.

Double habitable planets, or a planet with a large ocean moon would be cool, and sound possible. Extreme axial tilt could be interesting but the climate might not be very stable, or might stabilize in strange ways.
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