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2004 MN4, Even Higher Probability
Posted by
timothy
on Sat Dec 25, 2004 05:31 PM
from the keep-your-will-in-order dept.
from the keep-your-will-in-order dept.
phreakuencies writes "Worried since the recent post about the MN4 2004 asteroid, I added a bookmark to its 'impact risk' section at NASA. The asteroid started as having a 1/233 probability of hitting earth. Later it raised to 1/63. Daily computations made on 25 Dec raised its chances up to 1/45. Optimists can now say it has a 97.8% probability of missing earth." And Veteran writes " NeoDys offers the 'Orbfit' software package (source code released under the GPL) which can be used to get a pre-release view of the situation with Asteroid 2004MN4."
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Party like it's 2099 (Score:5, Informative)
The way I see it, we've got about 24 years to party before the world ends. Have another glögg [finland.fi]!
Seriously, if it hits 5 or greater on the scale, then we'll have reason to really worry. In the meantime, it's sufficient to just watch and see what happens. As phreakuencies pointed out, right now there's a 97.8% chance of absolutely nothing happening.
Re:Party like it's 2099 (Score:5, Interesting)
In any case, we have 24 years and it's not *that* big. Plenty of time to nudge it off course with some of those surplus nukes we have lying around if it is going to hit...
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Re:Party like it's 2099 (Score:4, Insightful)
This has been covered before, but the problem with hitting an large object hurtling towards something with a nuke is that afterwards you have a lot of much smaller hurtling bodies which are now radioactive.
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Re:Party like it's 2099 (Score:3, Insightful)
[1]If it is solid iron it won't shatter, just get thrown off course. But then it won't hit us at all - problem solve
Re:Party like it's 2099 (Score:4, Interesting)
Step one: Send out the bigass nuke right now. Put it on one of those ion engine crafts.
Step two: Nail the trajectory down to 99% accuracy.
Step three: Figure out the best way to deal with it. Have it pass by the earth into the sun? Have it slam into the moon? Is it possible to slow it down enough to put it into a stable orbit and mine it for resources later?
Step Four: Once the calculations are done, send the course corrections to our bigass nuke to put it exactly where we need it, and to detonate when we want it to. You don't hit the asteroid directly. You just get close enough and nudge it. This is why you sent the nuke so early, over time, a small nudge adds up to a huge course change.
Step Five: Placate the general public who were hoping they would have to send a mining team up in a risky yet heroic venture to save the earth.
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Re:Party like it's 2099 (Score:3, Funny)
I think it would take an election.
Let's say that the thing will hit (Score:5, Interesting)
Do powerful countries will prefer to do nothing to avert making a mistake that could possibly send the asteroid on their head?
What could possibly do a small country in africa if nobody wants to help them?
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Re:Let's say that the thing will hit (Score:5, Interesting)
To get a clue as to the answers, look at the recent devastating earthquakes in Iran - even though Iran was on his "Axis of Evil", Bush was offering aid almost immediately. Sure, besides the humanitarian side, there is also political capital to be made on such a gesture, but that's by the by. I have absolutely no doubt that if this, or any other asteroid, is going to hit us then every capable nation will be working 100% to prevent the impact, no matter where it might be.
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Re:Let's say that the thing will hit (Score:3, Interesting)
BTW, I can only assume that whoever moderated the par
Re:Let's say that the thing will hit (Score:4, Informative)
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Re:Party like it's 2099 (Score:5, Insightful)
Even if it does hit 5, it's worth noting that the probability estimation has changed twice in the space of a day. That's no insult to the mathematicians - I can't begin to grasp the variables involved here, but if the numbers can change that fast I think it's safe to assume that there's going to be more fiddling of the statistics needed in the next 24 years before we get an acurate projection.
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Re:Party like it's 2099 (Score:5, Informative)
Of course the statistics change - more measurements are being done, so the error margin on the estimate goes down. There is a band of possibilities, a bunch of possible trajectories, and more measurements make that band smaller.
Currently Earth is still within that band, and Earth's diameter is about 1/45th of the width of the band, so that's the probability of a hit.
Since more measurements are being done, we'll see this for a few more days - either the band is smaller and Earth is still within it, which raises the probability, or the band is smaller and Earth isn't in it anymore, and the probability drops to 0.
Saying this is "fiddling of statistics" is an insult to the mathematicians involved.
(Story above is simplified, by making it 2D instead of 3D, and by ignoring the fact that it's probably not some fixed area but the probabilities of the thing going outside the area are smaller and it's some weighted average, and I don't really know anything about the maths, I just think it's obvious that the probability would change quickly).
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Re:Party like it's 2099 (Score:5, Informative)
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Re:Party like it's 2099 (Score:5, Interesting)
The uncertainty is a long strip that is 0.018 (see NEODyS) of the Earth's radius wide, and many times the Earth's radius long. Go look at:
http://neo.jpl.nasa.gov/images/2004mn4b.gif [nasa.gov]
If the odds don't go down to zero soon, someone will calculate where the stripe of uncertainty is on the globe. It wouldn't be hard to do.
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Re:Incoming Asteroids? Use a nuclear warhead. (Score:3, Insightful)
Which Comes First (Score:3, Funny)
Duke Nukem Forever?
Re:Which Comes First (Score:3, Funny)
And assuming it does destroy modern civilization, then we only have 25 years left to get through to the people who still don't understand the difference between its and it's. Time for a crash program!
Whew (Score:3, Funny)
Good thing i read it over again.
Re:Whew (Score:5, Funny)
Good thing! If you hadn't, we'd be in some big trouble.
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Impact calculator (Score:5, Informative)
http://janus.astro.umd.edu/astro/impact/ [umd.edu]
The impact comes out as somewhere between 450MT and 1.6GT, depending on speed and composition
Re:Impact calculator (Score:3, Informative)
10 Bucks on Florida (Score:4, Funny)
'nuff said
Ohio (Score:3, Funny)
Wonder how the Christian fundamentalists in America would spind THAT.
We're doomed! (Score:4, Funny)
If this trend continues, expect an impact in another 4629 hours, or about 193 days!
It's going to be one hot summer...
;-)
Seriously, you might as well relax. (Score:4, Insightful)
That doesn't happen.
So kick back and relax in the knowledge that, even if a global catastrophe is imminent, there's fuck-all you can do about it, except make yourself a quick drink.
Re: Seriously, you might as well relax. (Score:5, Funny)
> You know in all those movies where some guy, sometimes just an amateur scientist, sees something in his telescope/seismograph/thermometer/disease-modelin
> That doesn't happen.
You're with the agency that makes those guys disappear, aren't you.
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Realize this... (Score:4, Insightful)
Kjella
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Science Desk Home for the Holidays (Score:4, Interesting)
I don't see a conspiracy here, and do think we will be missed, but given how much they hyped previous possible events with less statistical support it is curious they aren't doing follow ups. Could just be that it's Christmas, and things in the science departments are on autopilot.
If this thing stays greater than 1/100 by Monday, expect the papers and television to start picking up on it again. There was a close encounter today with 2004-vw14 (something like 5 lunar orbit distance), and the kooks where on the net prophesizing doom (even though it wasn't all that big a rock). It may take some years to really get a bead on where this thing is going, likely going up and down in probability.
Expect no fewer than a dozen Death-Cults if it stays in double-digit probabilities. Do the Darwin Awards cover Death-Cults?
Re:Science Desk Home for the Holidays (Score:3, Insightful)
Exciting! (Score:5, Insightful)
Re:Exciting! (Score:4, Insightful)
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Re:Exciting! (Score:5, Funny)
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Re:Exciting! (Score:3, Insightful)
Common mistake in press coverage (Score:5, Insightful)
It's important to note that if the chances of impact are 1 in 45, then the chances that future observations will exclude the possibility impact are 44 in 45.
The two events "asteroid hits us" and "we can never exclude the possibility of it hitting us" are equivalent: the first happens if and only if the second happens. Therefore the two events have the same probability.
So the "don't worry" part of the above sentence is pointless: the second half sentence is a mere reformulation of the first; there is no reassuring "extremely high" probability that future observations will correct the number downward.
Re:Common mistake in press coverage (Score:5, Informative)
Simple map of the Earth moon Sysstem:Simple map of the path of the asteroid:That should be 42 stripes but the junk char filter
As you see, the first stripe hits earth, the other 41 don't hit. Well, moon is in fact at opposite position when the asteroid comes in, but it was difficult to "draw" that. So, remember moon wont be hit.
Further observations of the asteroid will give us more data to determine wether the asteroid will travel stripe number 1 or 2, or wether it will travel stripe number 20 or 30 or whatever.
If we figure the asteroid is traveling NOT stripe 1 we are 100% certain that it will miss us.
If we figure the asteroid will not travel stripes 31 to 42, the likelyhood of an impact increased to 1:30.
Both calculations are "100%" certain. OTOH, your parent was right. The likelyhood that the chance of getting hit decreases is high. You have 42 draws
angel'o'sphere
Parent
Not too big a deal, I think (Score:5, Insightful)
I had to up the asteroid size to 1300 metres and a velocity of 14kps of dense rock colliding with porous rock before I could interpret the results as something that would suck for me (2nd degree burns on my body from the fireball).
There would be no major earth effects of such an asteroid hitting Earth, so it said.
Compare these stats against our current fearsome asteroid.
In one thread I saw someone refer to this as possibly a human-extinction event. I have a hard time believing that once I actually bother to go check this out. It'd sure suck for everyone within 100km of the impact site but for everyone else, I guess we'd have about the same effects as a major earthquake to deal with.
Re:Not too big a deal, I think (Score:3, Informative)
This one is 2.9 miles wide which is over 6k meters.
A 1300 meter meteor could easily create a 20 mile wide creater and could cause disasterous tidal waves and tsumias that extend many miles inland.
The human species would survive but 90% of us live near a body of water.
Re:Not too big a deal, I think (Score:5, Insightful)
Anyway, for large nuclear explosions radiation isn't an immediate concern. If you're close enough to catch much radiation you're already dead from the other effects. What kills you at distance is the overpressure wave and the radiant energy. The former knocks down structures and the second ignites fires that grow into firestorms.
If you think back to those early films of atomic bomb tests, that's why the paint on the house smolders (radiant energy) before being blown to kindling (overpressure wave). Terminator 2 showed the same sequence.
You might think you're safe from 2nd degree burns if you hang out side during the initial flash, but that won't do you much good if the house is blown down around you.
P.S., before somebody mentions it a nuke's nuclear reaction has stopped long before the fireball is a foot or so across - the size of the original warhead. Afterwards everything else is a case of extreme thermodynamics, the origin of the energy is irrelevant.
An impact's fireball is far more spread out, but it ultimately comes down to a very large fireball and local seismic effects.
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it actually can be a good thing (Score:5, Insightful)
Imagine how much technology boost all the related stuff will receive. If the Moon shot (the pure publicity stunt) generated so much progress, imagine this.
By the time we will know it is going to miss by 500km, we will already have cheap reliable interplanet travel and will be able to melt/mine/whatever the asteroids. Cool.
Maybe I'm a sick puppy.., (Score:4, Interesting)
Why? Simply because it would post such a great challenge for humankind. It could well bring much greater cooperation between countries, cooperation of a level presently unheard of.
Certainly, I'm not hoping it actually strikes earth, merely that people work together in order to stop it.
Just be glad that Bush won't be the president at the time. If it did hit, in US soil no less, then he'd start pouring billions per month into NASA for the development of spacecraft to fight the alien 'terrorists' who threw that asteroid at America.
Re:Maybe I'm a sick puppy.., (Score:4, Funny)
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The torrino scale creates unneeded histeric people (Score:3, Insightful)
With all those asteroids, it's always the same game: high probability at the start, it goes up or down and after 2 weeks, we've got some numbers that really mean something, but the problem is that during this time, people start freaking out because they would like to hold to some true numbers, not just "probabilities that are bound to change".
So, what we need to communicate with even more weight than those torrino scale numbers is a "measurement progress percentage" and tell everybody "if it's not 100%, don't worry yet". That way, with the always updated percentage number, the masses can reliably hold to something, and know that "progress below 100% means that what we know is not reliable".
Actually, for the current incident, we don't have this number, so I really won't wonder if some people will be freaking out over the next few days.
Astronomers: full exposure it the name of the game! Tell us how long it will take to measure the path, and where you are currently standing!
Thank you.
Re:The torrino scale creates unneeded histeric peo (Score:4, Interesting)
As far as a measure of progress, here's a simple one. At 100% progress the probability of impact is either 100% or 0%. Intermediate progress is the width of the window in which the impact might occur. If this window narrows to such a point that it does not include the earth, you get a 0% probability. If the earth is bigger than the entire window, you get a 100% probability. Anything else means there is more work to be done. The rate at which the window narrows will depend on the orbit of the asteroid, but that would give you a rough idea of when you'd be 100% sure.
If you are really curious, the locations and time of every observation that contributes to this is available online [unipi.it]. It's interesting to note that more observations were done today than any other day. This is a direct result of the object being identified as an object of interest on the Torino scale.
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"Earth Impact Effects Program" Calculations (Score:3, Informative)
My Parameters: Diameter 390m, Density 3000kg/m^3, Impact Velocity 11 km/s, Angle 45 degrees, Distance from Impact 25 km (sounds acceptably close but not "hey, it hit me on the head" close - if you are closer than that... though luck.)
If it hits Rock:
Final Crater Diameter: 4.87 km = 3.02 miles
The major seismic shaking will arrive at approximately 5 seconds. Richter Scale Magnitude: 6.6
But watch for the air blast... Max wind velocity: 186 m/s = 416 mph - Multistory wall-bearing buildings will collapse.
If you are at least 100 km away, you will still feel the earth shake and hear the air blast, but little damage will be done.
To sum it up, sorry, nope, humanity won't get extinct if this one hits us, and you won't be too affected unless you are rather close to it (100km) or if it hits water (Tsunami anyone) and you live nearby on the coast.
Re:Something to bear in mind (Score:5, Informative)
If the errors are Gaussian, if the nominal trajectory (i.e. "it misses the Earth by X+/-Y km") is accurate, but imprecise (that is, X is correct, but Y is large compared to X) then the probability of impact will decrease as the precision is improved (i.e. as Y decreases) because the "Earth impact" possibility moves farther out on the fringes of the observation, and the area doesn't shrink fast enough to compensate for this.
Of course, if the errors are flat (all solutions are equally likely - actually, if the PSF falls off slower than the area shrinks) then you're correct. I'm pretty sure that they're Gaussian, or approximately Gaussian, though. So the only way the probability could be increasing is if the nominal trajectory's impact parameter is decreasing - that is, closer impact.
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Re:Something to bear in mind (Score:3, Interesting)
What word did I use from Stat 101? PSF (point spread function) is from astronomy. It's what a high-statistics point source looks like on a CCD.
All the other words and ideas are just from error propagation. That's from my undergrad physics lab.
But in reality, you have no idea what models were used to calculate the estimates
It's on the page. 99% of the uncertainty is within 3 sigma. No extended tails, which means it falls off fast enough that you can say that yes, the sol
Re:I can see my house from here! (Score:4, Funny)
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Re:I can see my house from here! (Score:4, Funny)
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Re:I can see my house from here! (Score:3, Funny)
In all seriousness we all know Captain Kirk will find a Klingon bird of pray, fly around the sun to go back in time to get some Wales and snicker bars, then fly out to the asteroid and offer the Snickers bars to the asteroid to get it to not destroy us, while scotty cooks up some wonderful roasted whale to celebrate the saving of the earth.
Re:hitting the moon? (Score:3, Informative)