What Catastrophe Could Render Earth Uninhabitable in 40-60 Years?

[Steve Walmsle]

Hi,

I am putting together a scenario for a sci-fi computer game called Aurora and I am after some advice. I am trying to create a situation where Earth has perhaps 40-60 years before being destroyed or rendered uninhabitable. For the purposes of the scenario, the cause of this catastrophe of this must be evident immediately and conditions will gradually worsen until Earth is finally uninhabitable. The catastrophe must also be something that cannot be prevented. The only option will be to evacuate the planet, or at least save as many as possible. Depending upon the nature of the problem, it might be possible to evacuate to others planets in the solar system, at least temporarily. Ultimately, an evacuation of the entire solar system will be required. In Aurora there is no FTL travel but there are wormholes connecting between the gravity wells of stars. These will be the route of the final evacuation.

My problem is finding a suitable catastrophe to fit the above scenario so I looking for suggestions. It doesn't have to be likely - it only has to be plausible. My current line of thinking is a problem with the Sun. Perhaps some type of long term variability in luminosity or some scenario that involves the Sun beginning to move toward a red giant phase, although I know that there is far too much hydrogen remaining for that to happen without some external cause. Perhaps some form of cosmic radiation that gradually builds up over time, although that would have be local to the Sol system or the potential evacuation sites would also be affected.

I am well aware of my limited knowledge in this area so I thought it would be worth posting on this forum to try and get a more informed opinion. Any suggestions that would facilitate the above scenario would be very welcome.

Steve

 

[Arch2008]

Hi Steve,
How about a rogue black hole that is determined to merge with the Sun wthin your time frame?
http://www.sciencedaily.com/releases/2008/01/080109173835.htm

 

[bombadil]

Hi Steve,

Earth's magnetic field protects us from the solar wind, so you could claim that the Earth's magnetic field is dying out for some reason. This probably isn't going to happen, but that's why it's science fiction! Of course this scenario wouldn't cause anyone to want to leave the solar system.

Of course, ideally you could work your story such that the plot would be occurring billions of years in the future so the Sun entering the red giant phase could be the cause of apocalypse. Such would be more science, less fiction!

 

[Vanadium 50]

How about a Mayan prediction, and...never mind.

Seriously, I think you're looking at the wrong place if you're looking at the sun. Stars just don't have catastrophes on that time scale. I'd be looking more at volcanism. Look up "Deccan Traps", "flood basalt" and "large igneous province" - and imagine if all of the past events were to happen at once.

 

[bombadil]

If you really want to create a cool scenario then read "https://www.amazon.com/dp/0670019976/?tag=pfamazon01-20" by the astronomer Phil Plait, author of the "Bad Astronomy" blog. I bet you could find some interesting scenarios there.

 

[Ich]

For intelligent intervention, you could borrow a starbreaker or photino birds from Stephen Baxter.
If you prefer natural causes, let some heavy object disturb solar system dynamics such that the Earth (and other planets) leaves its orbit. There'd be all kind of earthquakes, cold and hot times - for years, if you like. And finally, Jupiter or some other planet pushes it near the sun, where it burns. All this can be known in detail before, and nobody can help it.

 

[Steve Walmsle]

If you really want to create a cool scenario then read "https://www.amazon.com/dp/0670019976/?tag=pfamazon01-20" by the astronomer Phil Plait, author of the "Bad Astronomy" blog. I bet you could find some interesting scenarios there.

Thanks to everyone who replied. That has given me some good ideas. The book above looks ideal for what I am looking for so I have ordered a copy. Thanks for the reccomendation!

Steve

 

[twofish-quant]

Sirius turns into a type I supernova or Betelgeuse goes type II. Gamma ray burster gets pointed in our direction. The trouble with that is that these things happen pretty suddenly. I suppose you could have a supernova that isn't quite enough to kill the earth, but is enough to cause enough damage that the ecosystems start failing.

Something else that could happen is that the sun could grow unexpectedly dimmer. It wouldn't take that much dimming to cause the Earth to start icing over.

Alternatively, you could imagine that greenhouse gasses, some unexpected eruptions and an increase in the sun causes the Earth to trip over some threshold and start a runaway greenhouse effect that turns it into Venus.

Nanobots.

Also since your universe has wormholes, I can imagine some seriously bad stuff happening there. What happens if a star gets sucked into a wormhole and starts slowly exiting out in the solar system. What if the wormhole is heading for the sun and starts slowly eating it up.

Or you could try a grand slam. Alien nanobots leaving a wormhole add enough mass to the sun to warm it up causing the Earth to trip into a greenhouse effect.

 

[berkeman]

Fun question, and intelligently asked.

Given the overall plot that you sketched, I think a massive object entering the solar system at a sun orbital-level velocity would be a good choice. It could be planet size, to make the effects more understandable to the average reader, compared to a black hole coming in. Kind of like a planet-size asteroid that is not on an immediate collision course with us, but does get caught in the Sun's gravitational well, and joins our solar system as a rogue planet on a bad orbital path.

The path will take it past the Earth in so many orbits, and that gives us some time to try to get off the Earth and maybe to Mars or something intermediate. But even Mars will get tidally destroyed by the close pass of the rogue planetoid at some point, so that's where your interplanetary travel thing could come in.

However, since interplanetary sub-c travel (don't know about your wormhole thing, I'm just an EE) would not be a great option, especially not for lots of people, consider having the survivors make a large number of sub-planets out of materials on the Earth or Mars, to launch into orbits around the Sun that are calculated to avoid close passes by the rogue planetoid. Lots of fun stuff to play with for making sustainable sub-planets (inverted, like Rama) by a desperate populace before the rogue planetoid gets too close for safe launches and constructions...

 

[berkeman]

...And the orbits of the sub-planets should be calculated to take them past planets and moons on a regular basis for re-supply of some materials, and for seeding robots to construct and launch more sub-planets.

Dang. I just realized something...