# Tag Info

1 vote

### Life on a Moon-like Earth?

Less dense = shorter lived magnetic field. Earth has a density of 5.51 g/cc. The moon has a density of 3.34 g/cc. Mars has a density of 3.93 g/cc. The moon is closer to Mars than to Earth as ...
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### Can Mars disintegrate entirely in this scenario?

Given " ... You can use millions of super-deep drillings and nuclear bombs to introduce fractures in the Martian crust if that helps.." then Ender Wiggins and Dr Device can make it a ...
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### Exoplanet sky with suspended ice crystals

Mother of pearl. Curiosity rover spies colorful iridescent clouds on Mars "If you see a cloud with a shimmery pastel set of colors in it, that's because the cloud particles are all nearly ...
• 272k
1 vote
Accepted

### Would a high iron content world have particular effects on its more common minerals/elements?

Depends on history of formation. In the proto-planetary disk, everything is kinda uniform. But once they go above certain size there is a lot of energy added via collisions, combine that with heating ...
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1 vote

### Would a lower gravity planet have deeper oceans and higher continents?

It can do. There are a couple of other variables you may want to consider as well as gravity: temperature and level of volcanic activity. Anything large enough to be classed as a dwarf planet by ...
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1 vote

### Would a lower gravity planet have deeper oceans and higher continents?

Looking at Mars, which has lower gravity than Earth, the crust does seem to be more uneven. It's home to both Valles Marineris, the deepest canyon in the solar system, and Olympus Mons, the highest ...
• 137

### Would a lower gravity planet have deeper oceans and higher continents?

Let's use our Solar System as sample to verify if planets with lower gravity have higher mountains, looking at the highest mountains in it. Name Height Location (surface gravity $m/s^2$) Olympus ...
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### Would a lower gravity planet have deeper oceans and higher continents?

Looking into your question, I found this at the Astronomy Stack Exchange: Does a planet's mass or gravity affect the height of it's mountains?. There's some mathematical and scientific things in there,...
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### Would a high iron content world have particular effects on its more common minerals/elements?

I've not read very thoroughly on this, but my interpretation of planetary formation implies that if such elements are abundant during the formation of planets a metal rich planet would have a variety ...

### Is this an accurate environment for life on a super Earth speculatively?

There are a number of issues. It is possible to have a planet with twice the size of Earth and a lower gravity, but it requires the radius of the planet to be at least 1.45 the radius of the Earth. ...
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### Is this an accurate environment for life on a super Earth speculatively?

Should be fine There was a time in the Earth's history where we had a lot of large animals. Look: Your world is like the prehistoric Earth. It is believable you have big animals too. There is no need ...
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Accepted

### Can Mars disintegrate entirely in this scenario?

Yes, and no need to introduce fast rotation, or nukes or anything similar. The Roche limit for liquid bodies is $d=2.544R \sqrt[3]{\frac{\rho_M}{\rho_m}}$, where $R$ is the radius of the more massive ...

### How to cool a planet's core to avoid inconvenient melting during deconstruction

Use the Sundiver Approach As in the David Brin book. Excess heat is converted to high frequency laser light and either beamed to the surface machinery or into space for other uses. The power is ...

### Can Mars disintegrate entirely in this scenario?

One part of the question says: Before the fly-over, Mars's rotation can be accelerated to up to 1 Martian day per hour if that helps Mars to disintegrate. Would that help Mars break up into pieces? ...
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### Can Mars disintegrate entirely in this scenario?

Keeping in mind many of the theories of the Formation and evolution of main rings. And as you mentioned Mars could travels within the Roche limit, Édouard Roche himself proposed that the rings are ...
• 1,285

### Day/night cycle and tracking celestial positions in S-type binary star system

I figure that you could have the star correspond roughly to centuries. Unfortunately, this system probably wouldn't result in a double sunset, and I would guess that the "Wandering Star" ...

### how would you call a star when referring to a "sunset" or "sunrise"

The names of the planet and the star are taken from Chinese language. Then why are you looking for sunrise and sunset in English? Take sunrise (Rì chū) and sunset (Rìluò) from Chinese also.
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Accepted

### how would you call a star when referring to a "sunset" or "sunrise"

Why wouldn't they still just call it sunrise/sunset? they would probably refer to the star at the centre of their solar system as a sun. It's a fairly common trope in sci-fi settings that Earth and ...
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### how would you call a star when referring to a "sunset" or "sunrise"

Not all languages use sunrise and sunset, your perspective is being skewed by using English. For example Italian uses "alba" for the moment when the star appears above the horizon and "...
• 237k

### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

If the binary stars are wide enough to allow the existence of a goldilock zone and the planet is located jn the goldlock zone between both stars then it could be possible. It would be an exotic view ...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

It's possible, with both suns similar brightness in the sky. How? A binary star, with a planet in the L5 Lagrangian point of the binary, which is stable. Ah, you say, but the suns will then be 60 ...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

Several answers have already dealt with whether or not this is plausible with two true suns, but assuming your romantic spaceman is mainly after the ambience of two suns appearing to set/rise at the ...
1 vote

### Lift 10 Billion Tons of Material From a Planet (Every Second)

Dust from the star NASA's WISE Catches Aging Star Erupting With Dust The star, catalogued as WISE J180956.27-330500.2, was discovered in images taken during the WISE survey in 2010, the most detailed ...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

Frame challenge: a synchronised sunset/sundown would be really underwhelming. The reason why sunsets and sunrises are romantic and dramatic is because they a) cause the sky to change (relatively) ...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

After considering many different configurations of star systems, I have decided that the most stable system where the two visible stars would always be 180 degrees apart as seen from the planet would ...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

L1 Lagrange point is not stable, and neither is the barycenter What you're asking about is the L1 Lagrange point, which is not a stable location. https://ke.gsusigmanu.org/3669-could-there-be-a-planet-...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

If we accept just enough of what we know about science, the result would be mega-cool suspension of disbelief According to an answer on our sister Stack, Astronomy, it's possible (and known) for a ...
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Accepted

### Lift 10 Billion Tons of Material From a Planet (Every Second)

Spread your efforts and quadratic growth Deconstructing a planet has advantages. The gravity gets lower with each kilo transported off planet, making it easier to escape it. However, thinking of only ...
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### Is it possible to have a habitable planet with 2 sun that have sunset for one and sunrise for the other at the same time?

an habitable planet with 2 suns that is in just the right orbit so that each day one sun sets at the same time the other rises For this to happen, the suns and the planet need to be on the same line, ...
• 237k

### Lift 10 Billion Tons of Material From a Planet (Every Second)

Nice question, I like the scale, but I would say it requires some better technologies for making K2, which with generative design systems and resources (computing power) when done on K1 scale, should ...
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1 vote

### How to Cause a Hydrosphere Apocalypse III: Erosion and a Shallow Sea

Rain from below. Continents sit on thick lumps of continental crust. These are the floats that keep continents up - without them, the continents would go down. Now, there's obviously no way on the ...
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1 vote

### Oxidized alkaline planets?

From a chemical point of view you could have a large amount of hypochlorite ($ClO^-$) salts, for refference bleach is mostly sodium hypochlorite. They would be the salts of the weak acid hypochloric ...
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1 vote

### What would happen on a binary planet if they captured a new moon into orbit?

I feel you need to find a different basis for your cataclysm. Good thing that there are lots. The tidal effect of object (comet, asteroid etc) large enough to survive to eventually form a moon on a ...
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1 vote

### Oxidized alkaline planets?

Playa https://en.wikipedia.org/wiki/Dry_lake A dry lake bed, also known as a playa, is a basin or depression that formerly contained a standing surface water body, which disappeared when evaporation ...
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### Can a planet stay cracked?

Even Creating a "Crack" is Impossible Let alone finding a way to make it stable. The Chicxulub impact created a geographic feature roughly 20km deep and 200km around. The kinetic energy that ...
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### Can a planet stay cracked?

It's easy to calculate the maximum permanent depth of a local, steep-walled crack in the planet: $Depth=strength/(density*gravity)$. Hydrostatic pressure in the rock at the crack's bottom can be ...
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1 vote
Accepted

### How would I calculate the greenhouse effect based on atmospheric composition?

I've found a way to calculate a surface temperature, but it relies on a constant, $\epsilon$, that doesn't appear to have an easy way to generate it. The function is:  \frac{S(1-A)}{4} = \sigma \...
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### Oxidized alkaline planets?

Lithium flats Logan Kearsley suggested a good idea in a comment here - potassium hydroxide as an example of an alkaline compound that is fairly hard to oxidize. (You can still do 2KOH -> 2K2O + H2,...
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### What would happen on a binary planet if they captured a new moon into orbit?

Start with a moon in a horseshoe orbit. Perhaps the moon was once stably trapped at L4 or L5, but this isn't necessary. One way or the other it got into a less and less stable orbit until it was in a ...
• 18.6k
1 vote

### How could large scale mining operations render an arid region unlivable?

Many fictional stories employ the device that mining or environmentally unsound activity has disturbed a chthonic (i.e. underground) species of "monsters" who are dangerous, causing them to ...
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### Can a planet stay cracked?

Short answer: I suggest you use a small, artifically shaped and terraformed mostly iron nickel world to have a crack which is very large absolutely and also relative to the size of the world. Long ...
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### Can a planet stay cracked?

Just have to start calculating pressure, gravity differences of $1500$ km depth. Pressure alone guarantees interesting things happening rapidly. With density same as earth radius $3500$ km, mass would ...
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### Oxidized alkaline planets?

If my chemistry knowledge is not too rusty, I think it is not possible, based on the following considerations: According to the theory of Brønsted–Lowry In the Brønsted–Lowry theory acids and bases ...
• 237k

### Can a planet stay cracked?

No, it couldn't be remotely stable, and erosion is not going to matter. Even assuming the crack got formed by some very 'gentle' process that didn't destroy the planet outright, you’ve got to consider ...
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Accepted

### How could large scale mining operations render an arid region unlivable?

Mine tailings The first thought was about all the acids that are used to extract the base elements from the ore. However, they would be deadly, but they will form a localised pollution. On the other ...
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### Can a planet stay cracked?

No, by definition. People still debate if Pluto deserves to be called a planet or not. The current definition has three elements: In orbit around the sun. Large/massive enough to reach a hydrostatic ...
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### How could large scale mining operations render an arid region unlivable?

It's already here on Earth, no further explanation needed. Surface-mining leaves large areas of surface barren and uninhabitable. It's the easiest, cheapest form of mining and the only one which is ...
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1 vote

### How could large scale mining operations render an arid region unlivable?

They cracked a underground volcano and triggered a massive eruption with an ash cloud from radioactive materials (the kind they were mining perhaps?) that covered the planet/region. Leading to a ...
• 3,607