Help with cilmate/astronomy for my world

[Phietadix]

For the world I am working on I need some help on the climate and astronomy. My world orbits a O-Type main sequence star, has two moons, and has in the center a valcano whose base is supposed to be roughly the size of Aursralia(Magicly formed of course). I need to find how these three things will affect climate, tides, etc. I also need to find out how far away form the star my world will need to be, as well as the sizes of the moons. My world is supposed to be earth-like in climate. It has Four large continents surounding the volcano. It must have a wide varity of climates.

 

[ThinkerX]

Type 'O' star? Yikes!

Some serious problems right there: First, 'O' type stars are hellishly bright and hot - if earths sun were a 100 watt light bulb, an 'O' type star would be...a really, really big halogen light, maybe a whole bank of them. A planet with a climate comparble to earths would have an orbit (year) measured in earth centuries...possibly a millenia. Even then, radiation would still be an issue.

The other big issue with 'O' type stars is that while bright and hot, they are also VERY short lived as stars go; a few tens of millions years and they're gone - not nearly long enough to form planets...though I suppose they could capture one that was floating free in interstellar space.

Two moons? Good chance their orbits are not stable over the long term. Eventually, one will either hit the planet, they'll collide, or one will be ejected. Depending on their size and distance from the world, there could be some interesting tides (really high or really low) when they line up.

 

[Saigonnus]

I am not a scientist/astrophysicist/vulcanologist, but I would think it is a work of fantasy... anything is possible though may not be realistic. That being said, I would think that the volcano is a bit large if it's base is the size of Australia, that would put the summit cone well into the upper reaches of the atmosphere if not outer space.

Mauna Loa; the world's largest volcano covers about 70 square miles at the base and stands over 13K feet above sea level... Australia covers 2.9 million square miles (closer to 3 million) and doing some quick computations it stands to reason if that if it is 43,000 times the size of Mauna Loa, the height would likely be about the same... so 13k x 43k is 559,000,000 miles... nearly twice the distance from the earth to the moon (238,000 miles).

You could probably have a volcano several times the size of Mauna Loa at the crux of the tectonic plates, and have it be very impressive, but likely it would simply be the main volcano and you'd still need others to complete the cycle of outgassing and magma displacement that goes on under the crust of any planet like Earth.

As for the moons, my planet has three moons, and I made the largest of them a similar size with our moon and a little futher away so all three have less of an effect on the tidal system of the planet. Basically just hand-waving the science aspect since it is a fantasy world and real world science need not play that critical of a role. I would think two moons more or less half the size of ours would speed up the tidal cycle a bit maybe two high tides in a day instead of one since they may pull in two directions.

For climate I would say follow the same "belted" form we have on earth, cold near the poles and progressively warmer the closer to the equator you get. That would probably give a good well-rounded ecosystem on all four of the continents depending on their orientation.

 

[Phietadix]

In reply to ThinkerX. I thought that someone might mention that O-Tpye Stars are too short lived. But this is not a problem as the world is created not evolved. If I have to I will move down to B-Tpye. The two moons are not very important and could be removed if too problamatic

 

[ThinkerX]

In reply to ThinkerX. I thought that someone might mention that O-Tpye Stars are too short lived. But this is not a problem as the world is created not evolved. If I have to I will move down to B-Tpye. The two moons are not very important and could be removed if too problamatic

The two moons thing would work, considering that this world would be doomed fairly shortly anyhow by astronomical standards.

 

[Phietadix]

I am not a scientist/astrophysicist/vulcanologist, but I would think it is a work of fantasy... anything is possible though may not be realistic. That being said, I would think that the volcano is a bit large if it's base is the size of Australia, that would put the summit cone well into the upper reaches of the atmosphere if not outer space.

Mauna Loa; the world's largest volcano covers about 70 square miles at the base and stands over 13K feet above sea level... Australia covers 2.9 million square miles (closer to 3 million) and doing some quick computations it stands to reason if that if it is 43,000 times the size of Mauna Loa, the height would likely be about the same... so 13k x 43k is 559,000,000 miles... nearly twice the distance from the earth to the moon (238,000 miles).

You could probably have a volcano several times the size of Mauna Loa at the crux of the tectonic plates, and have it be very impressive, but likely it would simply be the main volcano and you'd still need others to complete the cycle of outgassing and magma displacement that goes on under the crust of any planet like Earth.

As for the moons, my planet has three moons, and I made the largest of them a similar size with our moon and a little futher away so all three have less of an effect on the tidal system of the planet. Basically just hand-waving the science aspect since it is a fantasy world and real world science need not play that critical of a role. I would think two moons more or less half the size of ours would speed up the tidal cycle a bit maybe two high tides in a day instead of one since they may pull in two directions.

For climate I would say follow the same "belted" form we have on earth, cold near the poles and progressively warmer the closer to the equator you get. That would probably give a good well-rounded ecosystem on all four of the continents depending on their orientation.

The Valcano probably wouldn't be doing much magma displacment becausce it is only erupts twice in the entire history of the world. The first time is a worldwide catastrophe that destroys most (but not all) life on the planet. The second I haven't decided what will happen yet. (Posibly the end of the World)

The Valcano has to be huge. I don't want it to be anything like what we have on eath. I also want to to be impossible to form naturally. It is a signifant plot point and has to be something that is without a doubt caused by magic.

As for climate I was more asking the effect of these things on climate.

 

[ThinkerX]

Volcanoes and climate - we have more than our share of volcanic eruptions in this part of the world. Clouds of grit, turning the ky funky colors and wrecking havoc with engines and lungs. A big enough volcanoe would trip off an ice age.

On the other hand, volcanic ash is supposed to help plants grow.

 

[craenor]

First, let's talk enormous Volcano. Since you want enormous on a scale that just doesn't exist on Earth for your volcano, instead let's look at Olympus Mons on Mars.

Being a shield volcano, is has a mild slope, about 5 degrees. So while it is almost 17 miles high (over 3x taller than Everest) it is over 20 times wider than that at the base. That puts it on a scale that is just not equaled on Earth. I think something in that size range might work well for you.

However, if you make the base the size of Australia, even if you make it a shield volcano with a gentle slope, it's still going to be about 125 miles high, and that's just going to be problematic from a planetology standpoint. The physics/geometry/geology no longer quite work out.

Maybe go a bit bigger than Olympus Mons with a 25 mile high peak and a 500 mile wide base?

As to the moons, I don't see that being a problem. Put one distinctly farther away than the other. They'll align sometimes for some seriously wicked tides. And you'll have to account for there being a tide associated with each moon. So with one being closer and let's say more massive than the other, you would have a twice daily Primary High Tide, twice daily Primary Low Tide, twice daily Secondary High Tide, and twice daily Secondary Low Tide.

Then, on some schedule you work out, you'll periodically have a really high tide (Great Tide?) and a really low tide (Grim Tide?).

Lastly, for the O-Type main sequence star, that's going to have a few implications. People have already pegged on one big one, that being the star isn't going to last as long as most stars would. So that puts a timer on your world. But if this is a created world, then as others have pointed out, that's not a problem.

Ultimately it's going to mean that you'll be farther away from the star in order to still be in the liquid water zone. But despite being further away the star is going to be intensely bright. If you don't want everyone just crisping up from a few minutes outside, then the world is going to probably have a greenhouse gas, ozone layer, norther lights type thing going on.

So the upper atmosphere might be naturally a bit murky and diffuse the intense light some (that murkiness could be a positive side effect of the volcano, spewing ash, steam, and more so high up into the atmosphere), while allowing the world to retain more heat. Then at night the sky may light up with a crazy, huge aurora.

Good luck!

Edit: I accidentally a word.

 

[Jess A]

If you want to know how an enormous eruption will affect the climate of the world (in your second eruption), you might want to look up Yellowstone caldera. There is a documentary called Supervolcano, which is a 'what if this erupted' type of film. Yellowstone erupts and covers 3/4 of the United States in ash. The rest of the world is affected by the gases thrown up into the atmosphere. Also, there was increased volcanic activity in the Cretaceous period which changed the climate significantly. There are lots of good documentaries. Catastrophe - Catastrophe (TV series) - Wikipedia, the free encyclopedia - is also useful and fun to watch.

As for the height of the volcano, you might want to look at the largest mountain ranges in the world and see how that affects climate. Rain shadows for example, plant life, animal life. You can definitely have some fun with plant and animal life. One side might be a desert and the other a tropical rainforest - rain shadows. I'm not sure how large the effect would be with one huge mountain, and whether that effect would extend to the continents around it noticeably.

The equator and poles (and proximity of your continents to these) will affect climate.

Ocean currents is another area to look into. Those affect climate.

The nature of your world will affect what sorts of species exist and what evolutionary traits they have. Even a magical volcano can affect this, depending on how long it has been there.

I found a website that might be of interest: Plants under Alien Suns

Planets under O-type stars (sourced from the above link):

Autumnal to bluish colors. Main sequence stars brighter than the Sun (spectral types F and A and the very short-lived B and O) emit more blue and ultraviolet light than the Sun. Given sufficient time for Earth-type photosynthetic life to evolve (e.g., hundreds of millions to billions of years), planets around such stars could develop an oxygen atmosphere with a layer of ozone that blocks more energetic but potentially harmful ultraviolet but transmits more blue light to the ground than on the Earth. In response, life could evolve a type of photosynthesis that strongly absorbs blue light, and probably green as well. In contrast, yellow, orange, and red wavelengths of light would likely be reflected by such plants, so the foliage would have the bright colors found during autumn in Earth's deciduous forests all year round. On the other hand, some plants may reflect some blue light due to its overabundance and potential to "burn" photosynthetic organisms (e.g., like sunburn from ultraviolet exposure on Earth).

I guess it's a reminder that if things are created by a higher being(s), the higher power must create them to be able to exist and live under the planet's conditions. So life forms may have a resistance to extra energy and UV from the sun, for instance.

I hope this gives some clues to the climate.

 

[Phietadix]

Mauna Loa; the world's largest volcano covers about 70 square miles at the base and stands over 13K feet above sea level... Australia covers 2.9 million square miles (closer to 3 million) and doing some quick computations it stands to reason if that if it is 43,000 times the size of Mauna Loa, the height would likely be about the same... so 13k x 43k is 559,000,000 miles... nearly twice the distance from the earth to the moon (238,000 miles).

However, if you make the base the size of Australia, even if you make it a shield volcano with a gentle slope, it's still going to be about 125 miles high, and that's just going to be problematic from a planetology standpoint. The physics/geometry/geology no longer quite work out.

Why are these two heights so different? 125 mile or 559,000,000 miles?

 

[craenor]

Why are these two heights so different? 125 mile or 559,000,000 miles?

Well, it's important to remember that Mauna Loa rises 13,000 ft. above sea level. However, because the entire structure of it is all shield volcano, the actual base is on the ocean floor and makes it more like 56,000 ft. high, and its actual base area is much, much larger than the 70 square miles, but I'm not sure how much larger.

And though it's a gentle sloping shield volcano, Mauna Loa still has a steeper slope than Olympus Mons.

 

[Benjamin Clayborne]

Why are these two heights so different? 125 mile or 559,000,000 miles?

I think he meant 559 million feet, not miles. He multiplied 13k feet times 43,000 and then said 559,000,000 miles for some reason. 13,000 x 43,000 = 559,000,000, but if it's feet, then that's 105,871 miles.

 

[Phietadix]

I think he meant 559 million feet, not miles. He multiplied 13k feet times 43,000 and then said 559,000,000 miles for some reason. 13,000 x 43,000 = 559,000,000, but if it's feet, then that's 105,871 miles.

Ahh. That makes much more sense

 

[Saigonnus]

Just a bit of a typo... feet, not miles. Got my mind all befuddled by multitasking.

 

[Phietadix]

Maybe go a bit bigger than Olympus Mons with a 25 mile high peak and a 500 mile wide base?

Hmm. Sounds a little to small, , Also I looked up Olympus Mons on Wikipedia and it looks a bit too wide at the top. How well would it work if size was doubled then brought up to more of a Point? My Calculations put that somewhere in the thermosphere.

 

[Phietadix]

Also, if anyone would like to hear it, I could give a history of the Valcano. For now I'll Give the Phrase Associated with it.
"Behold and Beware the Mount of Adonai's Might"