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

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!

[fionbio]

It's hard to find such thing exciting if you have children.

Common mistake in press coverage

[AxelBoldt]

Many press reports essentially say "the chances of impact is relatively high with 1 in 45, but don't worry since it is almost certain that future observations will exclude the possibility of impact." Even the original NASA report contained a sentence like that.

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.

Not too big a deal, I think

[philovivero]

From the last post about this, I went and read up on the whole thing. I went to the beautiful CGI script where you input asteroid size and velocity and all that, and assumed I was 100km from the impact.

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

[coyote-san]

Maybe you'll "only" get second-degree burns from the fireball, but what about everything else in your vicinity exposed to the same energy?

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.

it actually can be a good thing

[BigGerman]

you know.

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.

Re:Party like it's 2099

[MoonBuggy]

Seriously, if it hits 5 or greater on the scale, then we'll have reason to really worry.

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.