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."

Comments

Impact calculator

[Nine Tenths of The W]

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

Re: Seriously, you might as well relax.

[Black Parrot]

> You know in all those movies where some guy, sometimes just an amateur scientist, sees something in his telescope/seismograph/thermometer/disease-modeling -software that all the high-up professionals miss, and rushes in to warn the government?

> That doesn't happen.

You're with the agency that makes those guys disappear, aren't you.

Exciting!

[DogDude]

Am I just sick, or do other people find the possibility of this thing hitting to be pretty damn exciting? The chaos, the devestation, the panic, the collapse of all social systems... jeez, that would honestly be one of the coolest (And last) things to ever happen in most of our lives. The timeframe is nice too... many of us that are currently in our late 20's, early 30's will be wiped out before things start going really downhill for us (physically), but we'll have enough time to get a decent bit of fun stuff done too. Bring it on!

Re:Exciting!

[zmooc]

One more reason for not having kids:)

Re:Something to bear in mind

[barawn]

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.

Re:Party like it's 2099

[TimToady]

Sorry, it's aimed mostly at the eastern hemisphere. If it hits, it'll be at about 9:22pm in London (.89 of a day at UTC), and since the rock is coming in almost directly from the night side of the planet, it's mostly aimed about 3 zones east of London plus or minus 6 hours. Or were you thinking that Iraq would have been renamed "Texas" by then?

Let's say that the thing will hit

[ArcticCelt]

Let's say for a moment it is confirmed that the thing will hit. Then we will have to determine where its going to hit. We know that damages will only be localized so if it is calculated that the asteroid will fall on an area populated by not so industrialized countries I am really curious how the world will react.

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?

Re:Let's say that the thing will hit

[Zocalo]

Or another possibility: what if it turns out that an impact will be on an industrialised country "Gog", sufficiently far from a political/economic rival "Magog" to offer no real threat to "Magog"? Would Magog dare to offer less than 100% of what it can offer to preventing the disaster, either publically or otherwise?

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.

Re:Party like it's 2099

[NockPoint]

When it is going to hit (if it does) is known down to minutes NOW. That and knowing which way it is coming from allows us to exclude half the planet from worries other than climatic. As someone has already pointed out, that means both NY city and Texas are safe from this rock.

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

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.

Re:Common mistake in press coverage

[angel'o'sphere]

Well, seems you don't get the problem.

Simple map of the Earth moon Sysstem:

1 _ _ _ 10 _ _ _ 20 _ _ _ 30 _ _ _ 40 _ _ _
E ... m

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 ... and in 41 draws you have the chance that stripe number 1 -- the stripe which hits earth -- is removed from the set or possible pathes. Because more accurate measurement shows that the asteroid wont go that path/stripe.

angel'o'sphere