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Near-miss from a city-killer asteroid this week


Werthead

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18 minutes ago, Free Northman Reborn said:

Your inside jokes are not amusing, True Kana Whatever and Jace whoever. Go find a room.

 

@Jace, Basilissa you better listen to him. He’s a random poster on this site, therefore you have to modulate your behavior as to not annoy him the second he shows dissatisfaction. 

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42 minutes ago, A True Kaniggit said:

Eh, I chuckled  giggled. Okay I'll be honest, my laugh is, and always has been, more of a giggle.

You just gotta learn enough material to get the references.

 

Edit: See? Case in point. Reading the post below, if your knowledgeable enough to get the reference, then that's funny.

Haha. Credit to you for your response. 

Anyway, this is a topic I find more important than most. Which partly explains my grumpy reply to your original light hearted post.

Carry on.

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59 minutes ago, Ser Scot A Ellison said:

Yes.  And cataloguing them without a mechanism for dealing with them doesn’t make much sense?

Yeah, why bother studying their projected vectors vs real ones, their orbits to see when they'll be coming back, or improve our ability to track them?  I mean, we might can figure all that out once we figure out how to land on one.  Why bother with anything?

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10 minutes ago, larrytheimp said:

Yeah, why bother studying their projected vectors vs real ones, their orbits to see when they'll be coming back, or improve our ability to track them?  I mean, we might can figure all that out once we figure out how to land on one.  Why bother with anything?

You’re missing my point.  I like studying astronomical objects.  But, in the context of what Wert shared wouldn’t it be a good idea to find a way stop an asteroid on an intersecting orbit?

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I am of the opinion that should a threatening mass be detected with sufficient time for response, the spacegoing nations could shock the world with a viable strategy.

Say, four or five weeks? I bet we could get a rail gun and a batch of nukes in orbit if we had over a month to figure it out. Now whether those items could do anything would depend on the size and density of the incoming, but stopping a meteor is secondary to providing a common cause around which multiple advanced nation states can collaborate.

In fact, best case scenario is we knock a chunk off, the rest hits and causes wide devastation and political agency for ensuring the next one gets destroyed completely.

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3 hours ago, Ser Scot A Ellison said:

And not a thing we can do to stop one of these fast movers.  All we can do is hope they continue to miss for the forseeable future.

Well, we can. If they were world-enders, over a kilometer across, there wouldn't be much we could do about it, but fortunately they're much easier to spot.

Asteroids in that size range can be pulled off-course by using Earthbound lasers, mass attractors (even a small spacecraft staying to the side of a 100m asteroid for several months would have enough of a gravitational impact to move the asteroid significantly off course) or crashing things into them. You can also nuke them at the last minute, although that is only effective if the asteroid is likely to break apart into pieces small enough to burn up in the atmosphere (although that would still give the troposphere a headache). If it's an iron-nickel asteroid, which will have picked up a fair degree of radiation in space, and you then nuke it into several sections which survive entry, you have of course made the problem considerably worse in terms of spreading the devastation over a much wider area and increasing the radioactive fallout.

The only caveat to all of that is that we'd need several years of warning to really do any of those things (apart maybe from nuking them at the last minute), which as this incident shows, may not be likely.

More cheerful is thinking that there are hundreds, if not thousands, of large long-period comets with an orbits in the thousands or tens of thousands of years which could come careening in at high speed from the outer Solar system with us having little chance of spotting one until a few months before impact.

1 hour ago, Safiya said:

It's the small ones I'm truly concerned about, imagine a small NEO than the size the US government has directed NASA to look for, not being identified as an asteroid and it hits a heavily populated area of a nuclear power and triggers a nuclear war? 

That could have happened with the Chelyabinsk meteor. It was only 17 metres in diameter and exploded 25 miles above the ground, but still generated half a megaton of explosive energy and injured a thousand people. If it had made landfall dead centre in the middle of town, I have a hard time believing that the Russian government wouldn't immediately assume it was some kind of nuclear attack.

In fact, if the 1908 Siberia impactor had been delayed in its arrival by about four hours, it would have landed pretty much right in the middle of Moscow and taken out the entire city. In fact, current estimates put the Tunguska object and this week's near-miss asteroid at almost exactly the same size, both physically and in terms of detonation (~15 megatons). The good news is that the Tunguska event happened in one of the most remote places on the planet and there were no confirmed human deaths.

 

Quote

 

Say, four or five weeks? I bet we could get a rail gun and a batch of nukes in orbit if we had over a month to figure it out. Now whether those items could do anything would depend on the size and density of the incoming, but stopping a meteor is secondary to providing a common cause around which multiple advanced nation states can collaborate.

This is, bizarrely, very close to the plot of the Ace Combat video game series, where an alternate-reality Earth (down to having a completely different geography, but everyone still flies American and Russian fighter jets because reasons) spots a large asteroid called Ulysses on a collision course and the nations of the world collaborate to build a massive railgun network to destroy it before it can land (which doesn't entirely work and smaller fragments pummel several continents, triggering a global refugee crisis that in turn triggers a world war).

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1 hour ago, Werthead said:

Well, we can. If they were world-enders, over a kilometer across, there wouldn't be much we could do about it, but fortunately they're much easier to spot.

Asteroids in that size range can be pulled off-course by using Earthbound lasers, mass attractors (even a small spacecraft staying to the side of a 100m asteroid for several months would have enough of a gravitational impact to move the asteroid significantly off course) or crashing things into them. You can also nuke them at the last minute, although that is only effective if the asteroid is likely to break apart into pieces small enough to burn up in the atmosphere (although that would still give the troposphere a headache). If it's an iron-nickel asteroid, which will have picked up a fair degree of radiation in space, and you then nuke it into several sections which survive entry, you have of course made the problem considerably worse in terms of spreading the devastation over a much wider area and increasing the radioactive fallout.

The only caveat to all of that is that we'd need several years of warning to really do any of those things (apart maybe from nuking them at the last minute), which as this incident shows, may not be likely.

That could have happened with the Chelyabinsk meteor. It was only 17 metres in diameter and exploded 25 miles above the ground, but still generated half a megaton of explosive energy and injured a thousand people. If it had made landfall dead centre in the middle of town, I have a hard time believing that people wouldn't immediately assume it was some kind of nuclear attack.

In fact, if the 1908 Siberia impactor had been delayed in its arrival by about four hours, it would have landed pretty much right in the middle of Moscow and taken out the entire city. In fact, current estimates put the Tunguska object and this week's near-miss asteroid at almost exactly the same size, both physically and in terms of detonation (~15 megatons). The good news is that the Tunguska event happened in one of the most remote places on the planet and there were no confirmed human deaths.

 Ugh.

Thanks Werthead. You actually stole all of my thunder. And made it very clear why it's best to read all of a person's post before responding.

First I got to the part about Terran lasers redirecting an asteroid, and hurried to mention how that would take years of advance warning to work. But then I see you addressed that in your next paragraph.

Then I see you mention the Chelyabinsk meteor, so I hurried to talk about the Tunguska event. But you'd already brought that up in your final paragraph.

I hope you're happy. I have absolutely no thunder for the rest of the day.

Edit: Anyone interested, here's the Wikipedia for the Tunguska object. https://en.wikipedia.org/wiki/Tunguska_event

Edit 2: Best I go play some Kerbals. Redirecting asteroids is always fun. You don't like it? Go dance with the angels.

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52 minutes ago, Werthead said:

.

 

This is, bizarrely, very close to the plot of the Ace Combat video game series, where an alternate-reality Earth (down to having a completely different geography, but everyone still flies American and Russian fighter jets because reasons) spots a large asteroid called Ulysses on a collision course and the nations of the world collaborate to build a massive railgun network to destroy it before it can land (which doesn't entirely work and smaller fragments pummel several continents, triggering a global refugee crisis that in turn triggers a world war).

Huh, how about that? I had a roommate who owned one of those games but I don't think I ever saw her play it. Sounds fun though. In my hypothetical the power players would use the threat to bind each other closer together at the expense of less wealthy nations. Unilateral trade agreements that globalize the oil resource (really just give it all to whichever states are making the rules), and mass work projects building SPACE DEFENSES that may or may not ever be deployed. 

World peace or something.

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DE-STAR is a potential answer. A massive phased array laser built in orbit, with the power to vaporize asteroids at a distance of millions of miles.

It is currently available technology. The constraint up to now has been the cost and practicality of constructing such a large structure in orbit. But with SpaceX’s Starship we will see costs of $100/kg to orbit - and eventually even lower - within the next 5-10 years. 

The more powerful the array, the larger the space rocks that it can vaporize in a shorter period of time. Build it large enough and you can melt any sized rock you want. (For example, at the extreme end of the scale, a Nicholl-Dyson beam can melt an entire planet in another star system light years away, using the power of the entire sun).

We are not talking of anything remotely at that level, of course, but at a $100/kg you can put a million tons of phased array and solar power panels up in orbit for just $100 billion. That will surely give you a planetary defensive system that can counter the vast majority of asteroid threats out there.

The key is the dramatically lower cost to space enabled by the revolutionary progress from SpaceX in particular.

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59 minutes ago, Free Northman Reborn said:

DE-STAR is a potential answer. A massive phased array laser built in orbit, with the power to vaporize asteroids at a distance of millions of miles.

Vaporising an entire asteroid is overkill; just vaporise a bit off one side, and the vapour will act as a thruster to change its course. A fraction of a degree is enough at those distances.

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48 minutes ago, felice said:

Vaporising an entire asteroid is overkill; just vaporise a bit off one side, and the vapour will act as a thruster to change its course. A fraction of a degree is enough at those distances.

Yes and to be fair that is indeed the initial approach the DE-STAR study proposes. But that was before the recent SpaceX driven prospect of dramatically lower launch costs. And DE-STAR does talk about scaleability to pretty much any capability that is desired - with increased power increasing the size of rocks that can be vaporized and/or decreasing the advance notice required to do so.

So the capacity I would be interested in is the scenario where a city killer asteroid is detected with only a couple of days notice. In that case outgassing based trajectory changes are probably not an option and vaporisation of the asteroid itself would probably be ideal.

 

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On 7/27/2019 at 10:38 AM, Safiya said:

We've catalogued hundreds of millions of NEOs; Near Earth Objects are defined as being within 150 million kilometers (93 million miles) of Earth. The estimated number of NEOs approximately one kilometer in diameter is 921±20.

Those over 140 m across is 27,100±2,200, and those 40 m (130 ft) in diameter is estimated at about 840,000±23,000. 

Then those larger than 3.5 m (11 ft)) is estimated at about 400±100 million. 

It's the small ones I'm truly concerned about, imagine a small NEO than the size the US government has directed NASA to look for, not being identified as an asteroid and it hits a heavily populated area of a nuclear power and triggers a nuclear war?

That we became extinct because of a 10 m lump of space rock. 

 

Tunguska was 70 m wide and leveled 2000 square kilometers (772 square miles). It didn't even hit the ground--it was an airburst.

Now imagine it impacting 3 hours later. Due to the Earth's rotation, it would have exploded over St. Petersburg. 

The 20 m diameter Chelyabinsk meteor exploded in February 2013 and injured 1500 people. And no one saw it coming.

It's a numbers game. Eventually we're going to get hit. It's just a question of when.

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19 hours ago, Free Northman Reborn said:

DE-STAR is a potential answer. A massive phased array laser built in orbit, with the power to vaporize asteroids at a distance of millions of miles.

It is currently available technology. The constraint up to now has been the cost and practicality of constructing such a large structure in orbit. But with SpaceX’s Starship we will see costs of $100/kg to orbit - and eventually even lower - within the next 5-10 years. 

The more powerful the array, the larger the space rocks that it can vaporize in a shorter period of time. Build it large enough and you can melt any sized rock you want. (For example, at the extreme end of the scale, a Nicholl-Dyson beam can melt an entire planet in another star system light years away, using the power of the entire sun).

We are not talking of anything remotely at that level, of course, but at a $100/kg you can put a million tons of phased array and solar power panels up in orbit for just $100 billion. That will surely give you a planetary defensive system that can counter the vast majority of asteroid threats out there.

The key is the dramatically lower cost to space enabled by the revolutionary progress from SpaceX in particular.

I think you're putting too much faith in SpaceX. They're in this for one reason: to make money. And the metals and minerals in the asteroids are worth a lot. The companies mining those asteroids (you know it's not going to be long till they do) aren't going to take kindly to their investment being vaporized like Alderaan. SpaceX might do it even so--but at a price, and probably a steep one. Who's going to pay it?

Also, if you hit it too close to Earth, you risk several smaller impactors instead of just one. Those smaller ones would be far more dangerous than the larger one. 

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On 7/27/2019 at 12:02 PM, Werthead said:

Well, we can. If they were world-enders, over a kilometer across, there wouldn't be much we could do about it, but fortunately they're much easier to spot.

Asteroids in that size range can be pulled off-course by using Earthbound lasers, mass attractors (even a small spacecraft staying to the side of a 100m asteroid for several months would have enough of a gravitational impact to move the asteroid significantly off course) or crashing things into them. You can also nuke them at the last minute, although that is only effective if the asteroid is likely to break apart into pieces small enough to burn up in the atmosphere (although that would still give the troposphere a headache). If it's an iron-nickel asteroid, which will have picked up a fair degree of radiation in space, and you then nuke it into several sections which survive entry, you have of course made the problem considerably worse in terms of spreading the devastation over a much wider area and increasing the radioactive fallout.

The only caveat to all of that is that we'd need several years of warning to really do any of those things (apart maybe from nuking them at the last minute), which as this incident shows, may not be likely.

More cheerful is thinking that there are hundreds, if not thousands, of large long-period comets with an orbits in the thousands or tens of thousands of years which could come careening in at high speed from the outer Solar system with us having little chance of spotting one until a few months before impact.

That could have happened with the Chelyabinsk meteor. It was only 17 metres in diameter and exploded 25 miles above the ground, but still generated half a megaton of explosive energy and injured a thousand people. If it had made landfall dead centre in the middle of town, I have a hard time believing that the Russian government wouldn't immediately assume it was some kind of nuclear attack.

In fact, if the 1908 Siberia impactor had been delayed in its arrival by about four hours, it would have landed pretty much right in the middle of Moscow and taken out the entire city. In fact, current estimates put the Tunguska object and this week's near-miss asteroid at almost exactly the same size, both physically and in terms of detonation (~15 megatons). The good news is that the Tunguska event happened in one of the most remote places on the planet and there were no confirmed human deaths.

 

This is, bizarrely, very close to the plot of the Ace Combat video game series, where an alternate-reality Earth (down to having a completely different geography, but everyone still flies American and Russian fighter jets because reasons) spots a large asteroid called Ulysses on a collision course and the nations of the world collaborate to build a massive railgun network to destroy it before it can land (which doesn't entirely work and smaller fragments pummel several continents, triggering a global refugee crisis that in turn triggers a world war).

Imagine world history if Moscow got obliterated.

If anyone is interested in the subject, I recommend John S. Lewis' A Rain of Iron and Ice. It was published in 1997 but still a good read.

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