Protecting Earth from Asteroids

[ysabetwordsmith]

Scientists talk about strategies. I'd like to see people actually doing things about it.

Proposal one: Deflect the asteroid with lasers.
Deflection is by far the best option when a threat is detected far enough in advance.  Because of parallax, tiny changes become big changes leading to a wide miss.  It's not hard to nudge things and you don't need a lot of energy.  The drawbacks are detecting the thing in time and reaching it at a distance.

Proposal two: Pulverize the asteroid.
While this can work, it is very difficult to achieve a sufficiently uniform destruction such that all pieces will harmlessly dissipate in the atmosphere.  Really hard.  Harder than rocket science.  Look at all the failures in rocket science.  There's a serious risk that you will simply turn a cannonball into grapeshot, which is just as deadly.  The one real advantage is it could probably  reduce a mass-exinction-sized rock into something small enough to survive better.

Of course, the first step is to map all near-Earth-orbit objects so we can spot threats before they flatten us.  Our record at this is not particularly good.  We need to invest more in detection, or else other solutions will do fuckall good.

Comments

[siliconshaman]

Problem is, doing anything requires investment, both money and political will.

Currently politicians are so short-sighted they're not even invested in climate change, which is both immediate and obvious.. much less an abstract danger like an asteroid impact. They just aren't taking it seriously enough.

It will probably take something like a city being turned into a crater before they decide sinking money into the problem is something they should do. And at that it'll probably be extracted from something like social welfare rather than the military budget.

Thoughts

[ysabetwordsmith]

>> Problem is, doing anything requires investment, both money and political will. <<

That is true. If a meteor craters a city, they might pull their heads out of their asses. I doubt anything less would do it.

>> Currently politicians are so short-sighted they're not even invested in climate change, which is both immediate and obvious.. <<

Also true.

>> much less an abstract danger like an asteroid impact. <<

There is nothing abstract about something that has caused mass extinction in the past and some alarming close calls in the present.

>> They just aren't taking it seriously enough.<<

Yyyyeah. I just want to draw dinosaurs saying their lines.

>>It will probably take something like a city being turned into a crater before they decide sinking money into the problem is something they should do. And at that it'll probably be extracted from something like social welfare rather than the military budget.<<

Honestly, if humanity gets creamed by a meteor, they deserve it. Their impact on the biosphere is already equivalent to that of an impact.

Re: Thoughts

[siliconshaman]

Well, it's abstract in the sense that they can neither see it or grasp the concept. I mean, we can talk about probabilities and mass extinctions... but to the average politician, those aren't real. Hell half of the American ones think humans used to ride around on dinosaurs and they went extinct in the flood because Noah left them off the ark. (or some such bullshit.)

What we'd need to get it through their skulls is stadium sized 'city killer' impact that actually does take out a city...

But until then.. heck, people are still saying that Elon Musk shouldn't be going to Mars, and don't accept that an off-site back-up of civilisation is good enough reason.

[kengr]

If the Tunguska body had arrived 8 hours later, it'd have hit Moscow.

That would have altered history in a lot of ways. One of which would be *knowing* that asteroids were a threat.

[siliconshaman]

Yup, it would've changed history, maybe even for the better...

Although, I may point out that Washington D.C could've also been a target if the timing had been a bit off...

Yes ...

[ysabetwordsmith]

That would make such an awesome anthology theme, Other Tunguskas! Ideally, have a mathematician work out the timing for other locations and let writing pick what they wanted to work with.

Re: Yes ...

[siliconshaman]

Now that's a cracking idea!! Hmm.. pity Bill Gawne isn't still around on social media, calculating that sort of thing is right up his street. He was even in the running for the NASA position of planetary defence coordinator at one point, IIRC.

Still, I wonder if I could find someone to do the maths? I could see how you could lay out the anthology by time, plus or minus X per chapter..

Re: Yes ...

[ysabetwordsmith]

Anthologies rarely have chapters, although occasionally they do if the material breaks down into logical clusters. Frex, Europe, Asia, and America would make possible chapters, if the stories spread out enough.

For what it's worth, I have editing skills, though not book-publishing skills.

Re: Yes ...

[siliconshaman]

True, not so much chapter as story.. Tunguska +8hr +12hrs etc etc...

I have some book publishing skills, just not so much editing... but I think it would require more writers...

Re: Yes ...

[(Anonymous)]

Technically you don't need to do the math...most people won't notice/care unless it does something obviously unscientific (i.e. looping around making graffiti in the sky, or hatching a baby kaiju, or whatever.)

Re: Yes ...

[ysabetwordsmith]

That depends on the genre. In fantasy or science fantasy, the parameters are pretty flexible. In hard science fiction -- like stories based on a historic event -- people will notice. In historic fiction, they will raise an absolute ruckus over tiny details.

[kengr]

DC is *way* too far south. Tunguska and Moscow are at the same latitude.

[kengr]

Alas, the laser option is not workable. Definitely not workable with current tech, and possibly not ever.

First, you can't send enough energy thru the atmosphere.

Second, we can't build big enough lasers in orbit.

Third, due to diffraction effects, the laser beam or pulse will get badly dispersed long before it gets to a distant asteroid (and there won't be *time* to deflect it if it's inside the diffraction limit)

Blowing up an asteroid is just a *trifle* difficult. Also, for the really big ones, breaking it into small pieces could make things *worse*.

If you break it into gravel sized chunks, you need to do it far enough away that they disperse and most of them will miss earth. Otherwise when they hit the atmosphere they'll deposit *more* energy into the atmosphere than letting the original body impact would have (really!)

Best near-term solutions are to set off nukes "near" the asteroid, but doing so on the proper "side" so that the resulting impulses will add up to deflect the asteroid.

And yes, "near" is better than on the surface. The x-ray flux will bot vaporize some of the surface material *and material below the surface. The below the surface explosions will blow off lots of rock and give even more thrust.

It'll likely take multiple nukes, but it should alter the trajectory quickly.

Another possibility is if we can land something on the asteroid that will set up a mass driver and start throwing bits of the asteroid away at high speed. Throw them in the right directions and they'll alter the trajectory. Will take years, but hopefully we'd have the time.

[siliconshaman]

If we've got enough time, the best solution is to park a probe on the surface, and fire up it's ion thrusters. It would take a Loooong time to change the asteroids orbit, but a small change early on would work, and all it has to do is miss, by how much doesn't matter.

Heck, if we catch it early enough, and can at least stabilise it's tumbling a bit, you could alter the orbit by painting one side of the asteroid white, and the other side black, and let sunlight do the work.