Slashdot Mirror
2004 MN4, Even Higher Probability
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."
The way I see it, we've got about 24 years to party before the world ends. Have another glögg!
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.
How am I supposed to fit a pithy, relevant quote into 120 characters?
Just to reassure you
http://janus.astro.umd.edu/astro/impact/
The impact comes out as somewhere between 450MT and 1.6GT, depending on speed and composition
Slashdot: News for Nerds, Stuff that matters only to them
Let's get the terminology straight here.
Chance is measured in percent. Probability is measured as a decimal or fraction between 0 and 1, with 1 being 100% certainty. Odds are measured as a ratio such as 1,000,000 to 1.
That's not necessarily true. It depends on the characteristics of the error.
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.
Bollocks. You just fed the percentage-to-fraction converter with a higher number.
Here some calculations I made via the Earth Impact Effects Program.
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.
+++ MELON MELON MELON +++ Out of Cheese Error +++ redo from start +++
Not necessarily, at least, not two cities on either side of the Atlantic. I live right on the coast (a few minute drive from the ocean) and using a script on NASA (?) somewhere to predict the impact, and if it was 2000 miles (or km) out to ocean (about the middle I think) and if it was about 1300 ft (I'm nearly certain, this was a few days ago) deep, I wouldn't even feel it, and the only thing that would occur would be some readings on local seismographs (of course, a few figures were estimates). I hardly think that it is going to be extremely destructive, unless it lands near a highly populated area or a major food producer.
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
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
1300 meters is not that big and they can travel up tp 80kps.
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.
http://saveie6.com/
Actually, I read something about knocking the moon out of Earth's orbit, viz "Space 1999", on one of those bad Sci-Fi science sites some time back. In a nutshell, the amount of energy required in a single blast to force the moon out of Earth orbit would infact vaporise it. The article didn't go into great detail about what the knock on effects with the remains would be, although disruption of tides would be a given. Then again, maybe not... If the impact was within a certain energy range then although the moon would be come molten and a large quantity of ejecta would be blasted into space, the vast majority of the mass would, although molten, still maintain its orbit.
UNIX? They're not even circumcised! Savages!
FYI...
When the probability got upgraded from 1.6% to 2.2%, the diameter got downgraded from 440m to 390m.
Exactly. Nudging it by a tiny fraction of a mile per hour with 20 years to go will make it clear Earth easily. 1 mph is more than enough with only 1 year to go. Actually, 1/2 mph is more than enough with 1 year to go, assuming you force it to go in the direction closest to missing the Earth, which is to say, nudge it max of half the diameter of the Earth in 1 year.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Here's a little animation showing what you're talking about.
You have just been hoaxed I bellieve.
Just look at the URL closely. this has got to be a joke on slashdot.
neo.jpl.nasa.gov/cgi-bin/ip?1replace the 1 with whatever you like and voila, instant impact probabilty to scare your freinds with.
Some drink at the fountain of knowledge. Others just gargle.
An s-type consists of nickel, iron, and magnesium - and an m-type - oh, my - what a motherlode one of those would be!
We can't do anything with materials in orbit right now because we don't have any materials in orbit right now.
We don't lack for methods of microgee refining (many experiments have been conducted) but we do lack for machines that have been designed to do it... currently.
With a sufficently large supply of raw materials we can substitute brute force what we currently do via expensive materials currently lifted to orbit - radiation shielding and structual materials, for example. Certainly many key components of a space station would continue to be needed to manufacture on earth, but the bulk structural materials of the ISS could be fashioned in space using in-situ materials - if we had those materials.
Imagine how much faster our space presence would grow if we didn't have to ferry up food and oxygen, just people and advanced devices.
Setting up a whole manufacturing industry in space is a long term investment, and I agree that few would make such an investment... but with the potential payoff in trillions, some will.
Lastly the cost of sending things down is a lot cheaper than sending things up, but you are probably right - most materials we make in space will stay in space.
Assuming that the thing hits us, we have LOTS more to worry about than only whether we personally get 2nd degree burns from the core fireball. Even if it hits on land, there will be a fairly wide zone of ejecta debris (hot rock) falling, starting fires, etc. If it hits in the ocean, it will be MUCH worse -- think colossal tsunami, as in several hundred feet. 1500 megatons is not the end of the world, but it is nothing to sneeze at.
If we are lucky enough to have it hit in a very sparsely populated land mass, then we have a big fireworks day, and some lingering weather effects (very red sunsets for years, and a cool decade). That is too much to hope for.
Realistically, whether it hits populated land or ocean, it is a mess. Although you may personally escape the impact or tsunami damage, no one will escape the economic damage, which will take years to recover.
Where will it hit? The time will be 9:21PM in London. It is coming at the earth from "behind" in its orbit. So, a 'direct hit' would be on the equator somewhere along the terminator (day/night line). Of course we don't know enough about the orbit to even know if it will hit, so there is as yet no way to tell where it will hit. Roughly any time zone from about GMT+8 to GMT-3 is at risk.
I'm currently choosing to be an optimist, even assuming that more certain observations confirm this to be on a collision course. My hope is that the global nature of the economic disaster will cause the nations of the world to fund a successful deflection mission, which will be cause for great celebration on that particular Friday the 13th.
Well,
... otherwise we would not get the 100% hit estimation. So, Merkur? The orbit of the asteroid is on Venus/Earth level, forget Merkur. Mars? Idem. So, Moon? Taken into account allready ... thats what astronomers do if you ask: "will it hit?"
... only the bullet. So we have to make snap shots of the bullet along its path ... with enough snapshots from different angels we see PRECISELY if it hits. Our current view on the asteroid shows a fan which is "42" earth radii wide. Remove one radius left and it misses, remove one radius right and teh propability increases from 1 : 42 to 1 : 41.
... thats exactly what I said :D
...
You are right, we dont have 42 draws.
We have as many draws as we do measurements. But if we measure after the first next attempt, that possibility number one is ruled out, the asteroid will miss.
Some of your post is basically right, but: the asteroid will have its close encounter in 25 years. Thats 25 rounds around the sunffor earth. And something about 36 or 27 rounds for the asteroid.
There is no physical problem in calculating that EXACT. Note: the asteroid is 440 meters in diameter. Earth is 12.000 meters. We are talking about several 100 asteroid diameters here.
You must consider this: an observation made today takes in no consideration the events that the asteroid will experience in the course of the next 30 years.
About what particular are you talking here?
Lets asume, tomorrow the astronomers say: we get a full hit. So what might happen to prevent that? Venus capturing the asteroid? No. Venus is taken into account
So whats left? A similar small asteroid orbiting more or less in the same hemisphere. How likely do you think is it in relation to the current 1 : 42 probablility that this 440 meter big asteroid hits another one?
Your consideration about:
By contrast, an observation made 10 minutes before the asteroid is about to hit us will have a great impact on the final outcome, because the total number of variables will be much smaller then. (Of course, the 10 minutes are just a ploy to get moderated up to funny, but you get my point, I hope).
I only get that you are completely mistaken.
When you aim a gun on a target, you ALLWAYS know if the bullet will hit. You know it when the trigger is pulled, you know it when it leaves the barrel, you know it when it has moved 1 meter, or 2 or 10, or 100. Its simple newton physics.
Same for the asteroid.
Our problem with the asteroid is: we dont see the gun
My guess is that, with a trajectory that's close enough to Earth's, you would see the probability of impact go up until, at a certain point, it either reaches 100% or drops abruptly to zero because of one decisive observation.
If you read my post again
If a certain posibility is ruled out, I called it "stripe 1", the probability of getting hit is ZERO. And we are 100% certain that it is ZERO.
Read here: http://neo.jpl.nasa.gov/news/news146.html
bottom animated GIF perfectly illustrates what I mean
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Sigh, the falling standards of education... "Gog" and "Magog" are two nations/tribes/persons that can be found referenced in the Bible, Koran, legends of Alexander the Great and numerous other places. In each case, Gog and Magog are usually connected with some great foe - for instance Marco Polo thought they were the Mongol hordes and the US and USSR were likened to Gog and Magog during the Cold War. In almost every case the legends/tales involve great devastation, the end of the world and general chaos. Given the topic at hand, it seemed a particurly appropriate combination of nations to use.
UNIX? They're not even circumcised! Savages!