Extreme Planetary Features vs realism

[Naima]

Ok back to some weird new Extreme planetary features :


Half emisphere Illuminated
A planet with only one side under sun and the other under night and an eternal twilight zone .

Red sun
As title says what woudl change , how woudl be the size of sun insky , how atmoshpere colors etc? Any influence on
possible civilizations?

Long/short day cycles
What woudl happen toEarthlike planets with a too short day cycle , like 6 -12 hours or longer like 48 - 96 hours? How would
life adapt?

Long/Short Seasons
Hw woudl change life on earthlike planets if the orbit around the sun was extreme slow or faster?

Increased mineral presence
How woudl be a planet gravity if its Iron mass was extremely more abundant than our planet or the opposite ?
How would

Acid Lakes
Are possible Acid like supersized lakes or even seas?

Binary/Trinary Star systems
how would life adapt and survive?

Gliese 667 Sunrise

[Ghostman]

Long/short day cycles
What woudl happen toEarthlike planets with a too short day cycle , like 6 -12 hours or longer like 48 - 96 hours? How would
life adapt?

The Earth itself may be used as an example, since it's rotation has been slowing down and continues to slow down. 620 million years ago the day was ~22 hours. It may have been something like only 4-5 hours at the time when the Moon formed. Life would probably adapt to a shorter day/night cycle quite easily. A longer cycle might be more challenging in arid climes due to the temperature changes (deserts get very hot during day and very cold during night; if both day and night last longer then there's more time for heating up and cooling down.)

Long/Short Seasons
Hw woudl change life on earthlike planets if the orbit around the sun was extreme slow or faster?

How long it takes to complete a near-circular orbit mostly just effects the length of seasons on the planet.

If the orbit happens to be very elliptic then it's duration becomes much more relevant because the planet's distance to the sun changes significantly throughout a year. Seasons might be more extreme for either the northern or southern hemisphere, and milder for the other. If for example the planet happens to be closest to the sun during the winter of northern hemisphere, then winters will be mild in the north and extremely cold in the south, with summers being cool in the north and extremely hot in the south.

[Naima]

So if the axial tilt is stuck vertically on the elliptical traje tory , the seasons would be always eternal and with slight ups and downs due to the distances ?

[Naima]

Thankyou , how many different abitable worlds you can Imagine? or Astronomy can define as abitable? from positions in the system to size, features, etc etc ... I really can think only of a few but I bet there are dozens of other combinations I Can't think of .

[BlackChakram]

Thankyou , how many different abitable worlds you can Imagine? or Astronomy can define as abitable? from positions in the system to size, features, etc etc ... I really can think only of a few but I bet there are dozens of other combinations I Can't think of .

I mentioned in this thread, that only real requirement for life as we know it is liquid water as a solvent and transport mechanism for complex organic molecules. Note that I said "as we know it". I suppose it's possible for some kind of life to exist without water, but it would be so foreign that we may not even be able to recognize or understand that it's alive.

So where do we get liquid water? The simplest model is based on distance from the star. This wikipedia article discusses that distance based on star size. We can modify this, though, from several things. If your planet is too far away, you need to warm it up. This could be through tidal forces like has been discussed here with Jupiter's moons. It could be a thick atmosphere that traps heat. It could be water deep underground that is warmed to liquid state by heat from volcanoes. Anything you can reasonably come up with here is good.

Same with being too close. You need to cool down to get liquid water. This could be in a band near the tops of mountains where things are cooler. It could be under an atmosphere that reflects the star's heat. It could be on the terminator of a tidally locked planet. Once again, any reasonable way you could conceive to drop the temperature.

As for size, I think someone already mentioned that here, but I could be wrong. Heavier worlds would create shorter, stockier creatures. I'm not a biologist, but I would assume you can reach a point with gravity where creatures can't hold themselves up, no matter how stocky or solid they are. Low gravity will breed more flying-type creatures. No need to waste energy if you can get around better by gliding than walking.

As for other features, I guess you'd have to look at that on a case-by-case basis. Mass Effect had the perfect example. On Palaven, the Turian homeworld, there was no planetary magnetic field. This allowed more dangerous radiation to reach the surface where it could affect the creatures. So life on that world evolved to have metallic components in their skin that could deflect / deal with this radiation. (They really nailed their science in that series.)

There probably are endless combos, but I can think of at least one. A planet in the path of a pulsar would get bathed with deadly radiation thousands of times per second. But you could have a planet and a pulsar arranged in such a way that only one latitude gets exposed, so you have a dead strip on the planet where nothing can survive.

Hope this answers your question!

[s0meguy]

There probably are endless combos, but I can think of at least one. A planet in the path of a pulsar would get bathed with deadly radiation thousands of times per second. But you could have a planet and a pulsar arranged in such a way that only one latitude gets exposed, so you have a dead strip on the planet where nothing can survive.

Hope this answers your question!

Wouldn't the gamma radiation just go through the planet and irradiate the other side too? As well as irradiate the atmosphere, that circulates on the planet between the part that is facing the pulsar and the part that isn't.

But perhaps complex life forms could develop that utilize the radiation could be possible under such circumstances too?

This article is about how at least a fungi can use radiation for sustenance.

Chernobyl Fungus Feeds On Radiation

[BlackChakram]

Wouldn't the gamma radiation just go through the planet and irradiate the other side too? As well as irradiate the atmosphere, that circulates on the planet between the part that is facing the pulsar and the part that isn't.

But perhaps complex life forms could develop that utilize the radiation could be possible under such circumstances too?

Gamma radiation can be stopped with 15 inches of lead or 3 feet of dirt.

The only kind of radiation or particle that would be able to go through a whole planet would be neutrinos, but the good thing is that they'd harmlessly pass right through you as well.

The fungus thing is cool, though. Could definitely present some interesting opportunities.

[Chick]

Just an off-topic comment .... when I saw this thread, I thought here is something I can really contribute to, having taught Planetary Geology at two different universities. Instead, I am really impressed with the number of people who have posted really excellent answers. Not sure why, but I pictured cartography as a technical art form, and instead I discover a lot of seriously good scientific knowledge here as well. Very cool!

[Naima]

Please post the most of the information you can , I sugest even to make possible scenarios , those could be usefull as well , let your ideas and fantasy go wild but tied to physics and universe laws .

[Naima]

Ok here is another question ...

I have a planet like earth , and I woudl like to have two moons , one double of moon the other sized as the moon , and by size I mean when seen by the ground , so they can be either smaller and more close or larger and more distant whatever fits best ...

then I was wondering if I can also add two suns , one as normal sun and the other as a much minor sun visible in distance almoust looking like a very bright star ....

what woudl be the problems and advantages of such a configuration? how would environments react and also how can I manage to enstablish the cycles of all the year and moon phases?

Also how those woudl have any effect on north pole , magnetism , tectonics, seasons , floods , weather etc?