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the Moon exploded and a planet about the size of Mars appeared If N'valdir is further away then the moon; but both the earth and N'valdir are caught in a gravity well with the moon. The moon then breaking apart due to tidal forces. That could have left both communities time to wonder if the result has a stable barycenter. If stable then I would expect the ...


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If the planets are on a collision course, they can't be stopped Simple physics, really. A planet has mass, and it takes force to move that mass. The more mass, the more force. How much mass does the Earth have? 5.9 * 10^24 kg. Mars is slightly less, 6.4 * 10^23 kg. So if we were to move one of them, we'd have to move the Mars one. The problem is that we don'...


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"Daughterless male release" is a very real, very plausible use of genetic engineering to try to control the spread of invasive species - most of the google results seem to relate to carp and other pest fish, but I'm sure I originally heard about it in relation to the cane toad in Australia. Basically you genetically engineer a sample of a species which is ...


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In general, predators require a large amount of energy intake and frequently have a big "range" that they traverse in the hunt for food. For a sudden boom in man-eating predators, there would need to be a big boost to the global food food supply (that initially isn't humans). I'd consider a two-part apocalypse: Stage 1 The famous company "XYZtech" develops ...


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A mutated retrovirus that makes us unable to break down starch or fructose. Or process common amino acids. Mass starvation ensues.


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It's not that far fetched. Just take a lethal flu virus, mix it with something like Ebola (you know, just in case your enemy hits and you want to retaliate) then accidentally (or not) release it in a hub of the western world and you can be fairly sure that most of humanity will be wiped out. Only those living in remote areas will be spared.


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Surprisingly, I find myself going against the obvious answer. You talked about decaying orbits in your question, everybody looked at that and quite correctly said no. However, if we remove the "decaying" part it becomes possible. Note that the catastrophic splash from the impact that Starfish Prime mentioned remains--I doubt there would be anyone left on ...


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SHORT ANSWER Your mechanIsm for making the Moon collide with Earth in 100 years would not work. LONG ANSWER PART ONE: ANOTHER SOLAR SYSTEM OBJECT COLLIDES WITH EARTH As other answers have said, you can not hit the Moon with a single impact that will change the orbit of the Moon so that the Moon will crash into Earth in 100 years. But it is perfectly ...


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It is probably not possible to achieve such a scenario, but exact calculation is extremely difficult due to many assumptions that would need to be made. Firstly because the Moon is so much more massive than the asteroid, the asteroid must be moving at very close to the speed of light to have a comparable momentum. In fact the asteroid would need to have a ...


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TL;DR: What you want is impossible for multiple reasons. Lets be honest: what you want is clearly impossible. In order to have a slowly decaying orbit, you need to have either a repeatedly applied or continuously applied force, such as a rocket engine, atmospheric drag, solar wind drag, multiple asteroid impacts... whatever. You cannot cause the moon's ...


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As I understand it, 1. An object is approaching Earth... Fair enough so far. A common sci-fi scenario is, an object is approaching Earth that is - say - a few miles or even 100 miles in size. That object is on course to hit Earth, obviously causing an insane amount of damage. Usually in such stories, we push it off path using nukes. So, such an object ...


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Nukes are the only sane thing to try, you get far more energy per pound than with anything else. However, you deliver them by missile. Their usefulness at planet-moving is basically unaffected by their velocity, all you care about is aim (you want them to come down at the point you want the planet moving away from) and detonation altitude. This is a ...


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Call your shot. Your incoming mass is near the size of earth - too big to move except with something else of comparable mass. Hmmm... Your world has an AI at its disposal that knows the site, mass and velocity of all objects bigger than 10 kg in its immediate vicinity. There is a mass of comparable size which could be made to intercept and ...


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There are two things that would help: Firstly this rogue planet needs to be detected a long time before it approaches. With a few hundred years warning, they might consider sending fleets of ships to set up at network of installations on the surface for setting off thousands of hydrogen bombs one at a time over a year or so. Although almost insignificant, ...


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Nukes(?) Given the ridiculous distances involved in space, if they discover it soon enough, they could attempt to redirect it. Normally, the only use for nukes in space is to detonate them in the Van Allen Belt and watch Fortnite players cry as the telecommunication systems of an entire planet goes down in a blaze of glory. That is because there is no ...


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