[What If} Massive Killer Asteroid to Hit Earth in 50 Years

[Lord MJ]

I wrote this blog earlier today, and thought it would be a good to share with SD.Net

A What If? Scenario I was thinking about today.

Lets say that an Asteroid the Size of the US is heading for Earth. Lets assume that scientists are able to determine that in 50 years the Asteroid WILL hit the Earth unless it is diverted. An Asteroid the size of the US is enough to shatter this planet of ours...

For the scientists here, would we in 50 years time be able to devise a method to stop an Asteroid the size of the US from destroying this planet?

A more relevant question to people not versed in that kind of science, what if the scientists came back and said, "there is nothing we can do, we are screwed, in 50 years this planet will be destroyed."

How would absolute certainty that the world will end in 50 years impact your life? Most of us will already be dead by that time. Would the knowledge that the world will end at a time after you have already passed on impact you in any way?

Would you still have children, knowing they would be wiped out? Then again, if you had a child today, he/she will be 50 years old when doomsday comes.

How would it impact society at large? Would doomsday in 50 years mean anything to most people today (who will probably already be dead before then). Would there be large scale rioting and lawlessness as a result?

Would you still push for the causes that you have been involved in, knowing that in 50 years, none of it will matter?

How about larger geopolitical factors?

[Samuel]

We can stop it easily. Specifically, we can just divert it so it doesn't hit us. Attaching a solar sail should do the trick.

Now, a black hole heading towards Earth...

[General Zod]

We can stop it easily. Specifically, we can just divert it so it doesn't hit us. Attaching a solar sail should do the trick.

Now, a black hole heading towards Earth...

A solar sail? For an asteroid the size of the US, in less than 50 years? That's a good one.

[weemadando]

We can stop it easily. Specifically, we can just divert it so it doesn't hit us. Attaching a solar sail should do the trick.

Now, a black hole heading towards Earth...

A solar sail? For an asteroid the size of the US, in less than 50 years? That's a good one.

The question I suppose would be how quickly can we get to where it is in order to attach it and minimise the alteration needed to create a "miss".

[Sky Captain]

An asteorid size of US is more like a dwarf planet than asteroid. There is probably very little what we can do to alter it`s course sufficiently to divert it from us. Even starting large scale deep space capable space program would take more than decade. Assuming we manage to build deep space capable ships and still have few decades time before impact it might be possible to alter asteorid`s trajectory by setting of a huge number of thermonuclear bombs on it`s surface kinda like nuclear pulse propulsion.

If diverting asteroid fails the plan B should be getting as much people as possible off world and setting up self sufficient colony whether on Mars or in space habitats. Preferably we should work on both goals to divert an asteorid and to build self sustaining space colonies.

[Junghalli]

A solar sail? For an asteroid the size of the US, in less than 50 years? That's a good one.

A sufficiently huge one might do the trick.

But yeah, we're pretty much fucked. Forget diverting it. Our best bet is probably some sort of self-sustaining colony on a Near-Earth asteroid or something. I could see knowledge of the event being kept from the public. Can you imagine the reaction to the knowledge that 99.999999% of the human race is going to die, among the public young enough to still be around for it?

[General Zod]

A sufficiently huge one might do the trick.

Good luck making one big enough with our current manufacturing capabilities.

[Sky Captain]

A sufficiently huge one might do the trick.

Good luck making one big enough with our current manufacturing capabilities.

Not to mention asteroid most likely would be spinning making impossible to keep that sail aligned against the sun.

[Junghalli]

Good luck making one big enough with our current manufacturing capabilities.

Hence why I said we're pretty much fucked.

[Alferd Packer]

I would think that, globally, the capability exists to A) ensure the survival of the species via off-world colony and B) make a serious attempt at diverting the asteroid. I feel, though, that such an effort will uniformly reduce the standard of living of the bulk of the world's population to extremely low levels, as entire world would need to commit most of its population to brutal labor to get the projects done within the allotted time. I doubt the will exists in the developed and developing worlds for that to happen.

[Sarevok]

What about building a massive underground bunker at the farside of the planet from the projected impact point ? It could be packed with supplies, people and industrial equipment. Given 50 years of global commitment to survival of human race it is not unfeasible to preserve civilization this way.

[Junghalli]

What about building a massive underground bunker at the farside of the planet from the projected impact point ? It could be packed with supplies, people and industrial equipment. Given 50 years of global commitment to survival of human race it is not unfeasible to preserve civilization this way.

That would probably be a good idea and we'd be able to save more people that way than via a self-sufficient colony in space, only problem is an impact that severe might well melt the crust. We're talking an impact on the order of the Big Whack here.

[Sky Captain]

What about building a massive underground bunker at the farside of the planet from the projected impact point ? It could be packed with supplies, people and industrial equipment. Given 50 years of global commitment to survival of human race it is not unfeasible to preserve civilization this way.

Not going to help because collision with asteorid size of the US (that`s something roughly few thousand km in diameter) will deposit enough energy to melt whole Earth if not blow it apart. Even before crust melts seismic shock waves generated by impact will destroy any conceivable underground structure.

[Kanastrous]

Hell, was Theia theoretically much bigger, than the US-sized body?

[Guardsman Bass]

Basically, we'll have to rush like hell, devoting as much resources as we can put there, to getting a self-supporting colony off-world (I'm guessing the Moon will have to do, although in fifty years time with "price is no object" you might be able to do a Mars colonY).

No idea on how many people you'd be able to get off the surface in that time - a lot of it depends on how quickly you build and design both your new home off-world and your spaceships to it. You'd probably be more free to take risks on the spaceships, building less-safe ones if they can get more people off-planet.

One thing, though - that sucker is fifty years out from impact. All you have to do is nudge it so that it barely misses the Earth (although even a near-miss would probably cause tons of earthquakes and the like) - how much could it take?

I could see knowledge of the event being kept from the public. Can you imagine the reaction to the knowledge that 99.999999% of the human race is going to die, among the public young enough to still be around for it?

Considering the size of the asteroid, you'd be hard-pressed to keep it a secret for very long.

For most of the population, this would basically be death - odds are they wouldn't be among the lucky few who might be able to live in self-sustaining colonies off-world, so they'd be stuck praying that this thing gets tugged on by Jupiter's gravity and misses Earth completely.

[Stark]

One thing, though - that sucker is fifty years out from impact. All you have to do is nudge it so that it barely misses the Earth (although even a near-miss would probably cause tons of earthquakes and the like) - how much could it take?

You mean, what the everyone has already been talking about? It's the size of the goddamn US.

Is it even plausible to create a proper offworld colony in 50 years? How much ejecta from such a massive impact would there be, and how would this affect orbitals or the moon?

[Guardsman Bass]

One thing, though - that sucker is fifty years out from impact. All you have to do is nudge it so that it barely misses the Earth (although even a near-miss would probably cause tons of earthquakes and the like) - how much could it take?

Is it even plausible to create a proper offworld colony in 50 years? How much ejecta from such a massive impact would there be, and how would this affect orbitals or the moon?

No idea - we've never been at a point where getting as many people into a liveable environment in space has been the first and foremost priority for all of human civilization before.

[DaveJB]

I just plugged the figures for the type of meteor impact in question into an impact calculator, using a 3000 mile diameter as a ballpark figure, and made of iron so that we're as fucked as possible (such a large object isn't going to be made of ice, anyway). Here's the one I used, for reference.

In summary, while it wouldn't actually destroy Earth per se, it would melt 84.28% of the crust, meaning that we're going to have a planet-wide sterilization of all life and organic matter. Best thing about the situation would be that Earth's orbit wouldn't be disrupted, so a lunar colony might have a chance of survival, assuming that it wasn't pulverised by the ejecta - placing it on the dark side of the moon would probably be the best idea. Of course, actually setting up such a colony in 50 years is a different matter.

[Erik von Nein]

Yeah, set up a moon colony. Good plan. Then what? Even if they survive the initial impact it's not like they're going to have any kind of support. They won't be able to live there indefinitely.

[DaveJB]

Hey, I just said that was the best way of surviving the initial impact - I never claimed to be a long-term strategist.

[Stark]

That's what my question was really about; even if we wanked out and got really lucky, I don't think it's remotely plausible to get a viable population offworld indefinately (and if the crust is melted you ain't never coming back).

[GrandMasterTerwynn]

I just plugged the figures for the type of meteor impact in question into an impact calculator, using a 3000 mile diameter as a ballpark figure, and made of iron so that we're as fucked as possible (such a large object isn't going to be made of ice, anyway). Here's the one I used, for reference.

In summary, while it wouldn't actually destroy Earth per se, it would melt 84.28% of the crust, meaning that we're going to have a planet-wide sterilization of all life and organic matter. Best thing about the situation would be that Earth's orbit wouldn't be disrupted, so a lunar colony might have a chance of survival, assuming that it wasn't pulverised by the ejecta - placing it on the dark side of the moon would probably be the best idea. Of course, actually setting up such a colony in 50 years is a different matter.

What velocity did you use? I plugged in 51 km/sec under the assumption that such a body would be falling into the solar system from somewhere out of the Kuiper Belt, Oort cloud, or from interstellar space. The effects on the Earth were as follows:

The Earth is completely disrupted by the impact and its debris forms a new asteroid belt orbiting the sun between Venus and Mars.

Which suggests that a Lunar colony would be fucked seven ways from Sunday when the Moon starts sweeping up all that debris.

To be on the safe side, you're going to have to place your colony out among the asteroids. You could reach the Earth-crossers fairly easily, though the task of building a self-sustaining colony in fifty years with the interesting effects that facing the impending destruction of Earth is likely to have on the the global economy, national governments, and religious entities, is going to be a seriously daunting one. At our average level of advancement, it may well be entirely insurmountable.

[Junghalli]

Yeah, set up a moon colony. Good plan. Then what? Even if they survive the initial impact it's not like they're going to have any kind of support. They won't be able to live there indefinitely.

It is theoretically possible to survive on the moon indefinitely, with appropriate technology. Actually getting it to work will be a bitch though, especially as nobody's ever tried anything like this before.

The moon might not be the best place to set up such a colony though. I'd prefer someplace with more ready access to water. Mars maybe.

It's not like we really have any better options. I wouldn't want to be in even a well-protected bunker on Earth when the impact happens, and trying to send a starship to another habitable world (even assuming any exist in our immediate neighborhood) will entail the same problems as with presently feasible technology it will take centuries or millenia to get there, so we're talking a generation ship.

[DaveJB]

What velocity did you use? I plugged in 51 km/sec under the assumption that such a body would be falling into the solar system from somewhere out of the Kuiper Belt, Oort cloud, or from interstellar space.

About 20km/s, I think - however, that's the figure for an intra-system collision with a large object, which as you point out may be a flawed assumption (Ceres is the largest such object that would qualify, and it's only 950km in diameter). Really though we're hosed in the long term whether Earth is sterilized or destroyed outright, so either of our figures is bad news.

[CaptainChewbacca]

If the world, as a whole, devoted all available resources to getting a self-sustaining colony on mars, we could do it in 50. We don't have to worry about long-term survivability of the ecosystem, so we can start lobbing Orion-sized payloads into orbit, getting as much heavy equipment as we can to safety.

I imagine we would start getting stuff to the moon as quickly as we can as a sort of 'staging area', since once its there it will be safe, and then move stuff from the moon to mars as the new colony is ready for it. Seed vaults, libraries, and probably some intrinsic art objects will be saved. We have 50 years, we can get a lot of nonliving material off the earth before that happens.

By the time the impactor comes, we could probably have a colony on mars of a few thousand that is self-sustaining and able to expand. As for on earth, we might try building a number of identical habitats far underground, spread out geographically. Since we won't know WHERE its going to hit, we have to hope that a few are far enough away to survive and wait out the ordeal. If we have people in orbit working to get the dust out of the atmosphere and perhaps divert some comets to restore what we need, people could conceivably return to the surface in as little as 50 years.