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Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

cneos.jpl.nasa.gov

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Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#271

Post by echoangle »

chrsw wrote: post #78
ta1243 wrote: post #32

Earlier quoted context omitted.

That would create far more objects, many on the same rough direction, thus increasing the chance of an impact

Only if you managed to leave the trajectory the same if it was already on a collision course or change the direction to a collision course. Do you think you can control that with a nuclear explosion? You probably don't know enough about to the system to make a high confidence prediction of the new outcome.

Not really, blowing it up is going to create a lot of fragments with slightly different orbits, and some are going to have practically the same as the whole Asteroid had before. So the chance of anything at all hitting earth will increase, but the parts will be smaller. It would be like a bullet turning into buckshot during flight.

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#272

Post by pbmonster »

xenadu02 wrote: post #190
i_am_a_squirrel wrote: post #178

Is there a "sweet spot" for asteroids where they don't impact the earth, but come within like 20 meters of it? Like is it possible for an asteroid to give a city a "buzz cut" and then continue on into outer space?

Anything that comes closer than the ISS (give or take) is going to interact with the atmosphere which is going to change the dynamics considerably. Generally something with the right orbit to pass 20m above the earth's surface is going to burn up in the atmosphere or hit the surface. The drag is going to kill its orbit fairly quickly. To have enough energy to come that close without doing so means it has enough energ…

If you come in at exactly the right angle (because you'll skip off the upper atmosphere if you come in too flat) and if you're fast enough, it's entirely possible to enter the atmosphere but fail to complete the aerobreaking maneuver, resulting in an exit from the atmosphere at above escape velocity.

The stress of this maneuver is considerable, especially if you get as low as 20m above ground, so the object would need considerable shear strength and yield strength. Also high density and high thermal capacity. But not unrealistic, I think a tungsten ball (or better yet, a solid tungsten lifting body with aerodynamic steering authority) should make it through.

You can even exit the atmosphere but not have escape velocity, effectively using the aerobreaking maneuver to assist in the gravity capture of your object. But you'd better circularize the orbit shortly after, otherwise your next pass through the atmosphere is going to be terminal.

Relativistic baseball effects aren't very relevant yet, I'm talking about objects hitting the upper atmosphere with around 20-50 km/s. Enough to leave again, not enough to start a fusion reaction.

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#273

Post by tim333 »

i_am_a_squirrel wrote: post #178

Is there a "sweet spot" for asteroids where they don't impact the earth, but come within like 20 meters of it? Like is it possible for an asteroid to give a city a "buzz cut" and then continue on into outer space?

I don't think a 20m buzz cut and back to space is possible. To get back to space you need at least low earth orbit velocity which is about 16,000 mph and stuff going that speed low in the atmosphere gets very hot and would probably melt and break up. Maybe if it was a big one some would break off and some make it back.

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#274

Post by looofooo0 »

ddahlen wrote: post #84

I work on the Near Earth Object Surveyor space telescope (NEO Surveyor) writing simulation code which predicts which objects we will see. This one has drummed up a bit of interest due to its (relatively) high chance of impact. I actually spent quite a bit of time yesterday digging through archive images trying trying to see if it was spotted on some previous times it came by the Earth (no luck unfortunately). Since w…

Do you know people worrying about supervulcano erruptions?

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#275

Post by defrost »

looofooo0 wrote: post #274
ddahlen wrote: post #84

I work on the Near Earth Object Surveyor space telescope (NEO Surveyor) writing simulation code which predicts which objects we will see. This one has drummed up a bit of interest due to its (relatively) high chance of impact. I actually spent quite a bit of time yesterday digging through archive images trying trying to see if it was spotted on some previous times it came by the Earth (no luck unfortunately). Since w…

Do you know people worrying about supervulcano erruptions?

https://www.usgs.gov/observatories/yvo

https://en.wikipedia.org/wiki/Yellowstone_Volcano_Observator...

How concerned? https://www.agiweb.org/geotimes/june05/feature_supervolcano.... not very.

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#276

Post by dash2 »

freen wrote: post #132
timewizard wrote: post #124

Earlier quoted context omitted.

There is open doubt as to whether climate change, as presented, is truly a near-term existential issue. There is no doubt that an asteroid hitting earth is.

There is an open doubt whether a fully functional coffee machine is currently orbiting Venus, however one of these hypotheses is different than the other. Hint: expertise matters, evidence matters, and in a field where buildings/laws/fields of study get named after successful contrarians, a long streak of effectively unanimous consensus should not be undervalued.

The good news is that the near-unanimous consensus among experts is that climate change is not an existential issue. Almost no climate scientist thinks that climate change could wipe out the human race. (That's compatible with it having very large effects on human welfare, substantial percentages of global GDP.)

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#277

Post by elric »

Willingham wrote: post #117
elric wrote: post #112

Earlier quoted context omitted.

I don't think I understand your comment. The yield of nukes is of no consequence if they're not being used, so I don't think the comparison stands?

My point is, we have used nukes, so we know exactly what the worst case scenario is, and that’s about 20-50 million lives(hitting Tokyo or NYC). Equal to the number of deaths during the Spanish flu or half of world war 2. I think the comparison helps us understand what the risk truly is. I think the world would panic and likely loose more lives through chaos than the actual impact.

Losing 20-50 million lives through "panic" seems like a crazy estimate. What are you basing this on?

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#279

Post by baq »

bananaflag wrote: post #261
baq wrote: post #248

Earlier quoted context omitted.

Looks like alpha zero stole the original meaning of Monte Carlo… it is not required to have players, or a game, to use the method: https://en.m.wikipedia.org/wiki/Monte_Carlo_method

It wasn't stolen, it was a well-established particular case well before alphago https://en.wikipedia.org/wiki/Monte_Carlo_tree_search

I only meant the total mind share :) looks like folks have never heard of MC in other contexts than game bots.

Re: Asteroid Impact on Earth 2032 with Probability 1% and 8Mt Energy

#280

Post by andrepd »

VierScar wrote: post #137
renjimen wrote: post #123

Earlier quoted context omitted.

Parent mentioned Monte Carlo simulations, which allow you to simulate across a range possible scenario parameters and see what % result in some outcome (like a collision with Earth or the moon).

I'm sure there's a reason, but it seems like an unusual use of Monte Carlo - it's all deterministic and there is no opposing player making choices. Must have something to do with uncertainties in projected orbits or imperfect simulations maybe?

It's "deterministic" the same way the weather is.
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