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Asteroid 4179 Toutatis Will Miss Earth, This Time
EtherAlchemist writes "National Geographic News reports in this story that a giant, peanut shaped asteroid known as 4179 Toutatis will pass within 1 million miles of Earth on Weds, the 29th. When it does, it will be the closest any known object of this size (3 miles) has passed near Earth in this century. No worry about impact yet, it should pose no threat until at least 2562. An interesting note: the asteroid believed to have caused Earth's biggest mass extinction is thought to have been between 3.7 and 7.5 miles as reported here in 2001." 2004 FU162 came closer, but is a much smaller object.
I'm getting kind of sick of this type of story. It seems like every few months their are stories released about some space object coming close to earth and 'just barely missing'.
Though I am curious to know if their is an official plan for countering a colliding asteriod? What would our options be realistically if an asteriod going to impact in a matter of months?
I'll make you a deal. You pray to God for help and I'll stop the moment he shows up.
Method 1 is novel, but probably wouldn't produce enough of a course change to matter... we'd still die (remember we're unlikely to spot an asteroid until it's way too a late for minor course changes to make a difference).
Method 2 plain wouldn't work. Asteroids aren't solid objects so they can absorb a lot of shock, plus if you managed to break it up all the little bits would have the same total velocity as the original asteroid... death by a thousand cuts.
That is the meaning of the grandparent post.
You do realise surely that 1000 small asteroids is a lot better than 1 large asteroid, right? The effect of 1000 small chunks would be greatly reduced due to them burning up faster while descending through the atmosphere. Same total velocity my ass, i'm all up for air resistance.
telling the public would be stupid... so we won't know about it
Not at all. The news would probably leak out, and there would still be a panic.
What you really want to do is tell people about the rock, but tell them it'll just a be a near miss, a million miles or some such. Nothing to worry about.
Wouldn't it be easier to say 6 to 12 Km?
we would regard it as "none of our problem", but the technology would continue to evolve.
in couple of generations people would start making up some plans to escape from the disaster.
world was created 5 seconds before this post as it is.
Why?
Because a billion tons of gravel travelling at 25,000 miles per hour is just as deadly as a billion ton chunk of rock travelling at 25,000 miles per hour. It's not the rock itself that's the problem. It's the kinetic energy from the object's mass that's the problem. Gravel - rock - it's all the same at 25,000 miles per hour...
The only way a nuke really would work would be if it were small enough to nudge it off course, wihich would mean getting a BIG lead time on it. and that assumes that the asteroid is solid. It seems a lot of them aren't all thet well put together and a nuke would only turn the bullet/asteroid into a shotgun blast, per my previous description.
RS
Shoes for Industry. Shoes for the Dead.
Even if such an object hit Earth, I seriously doubt that it would lead to human extinction. In fact, it probably won't even kill as many people as the tens, or possibly even hundreds, of millions we have killed during the 20th century in two world wars, many other wars, and persistent indifference to humanitarian crises of famine or disease. This may be a young crowd, but those of us old enough who have grown up during the heat of the cold war will probably have less to worry about from a meteor hitting than all those tens of thousands of ICBM the USA and USSR seemed willing to unleash on each other and everyone at a very short notice.
Many species survived many mass extinction events, and, ironically and in fact, many of such species have been, or are being, driven to extinction by none other than us. Soon we will have successfully driven biodiversity to the minimum we have allowed to survive because we want it, such as dairy and poultry farms, and pets.
I am willing to bet that the last surviving species on Earth will be humans and microbes.
It all depends on how big it is, how fast it is, and where it is going, where it gets turned to gravel and how big the gravel is. If it is far enough out most of the gravel will completely miss, if it is too close in it and a lot of it will simply be like worrying whether a puppy will be hurt more by a shotgun or .44 at medium range.
There's a lot of room between the rocks out there. If something is big and fast the earths gravity won't change its course much to pull it in, we are a moving target, and nothing is aiming for us anyway.
Let's do the math on burning the asteroid up in the atmosphere. Assume you have a 3-mile diameter asteroid going at 50,000mph. That's 5.7e10 m^3 of rock; assuming 5 tons/m^3, mass = 2.9e14 kg. Energy = 0.5mv^2 = 7.2e22 joules.
Assume a blob of gravel of this mass hits one side of the earth evenly distributed over an entire hemisphere over a 1 minute time span. That deposits the energy over 2.6e14 m^2 surface area in 60 seconds, for a total power flux of 4.6 megawatts per square meter of the entire earth; about 4000X the brightness of the sun for 1 minute. Even if the burnup occurs high in the atmosphere, the power influx at the surface would not diminish because the radiation is coming from the whole sky, not from a point source.
Bottom line, everything would fry.
If you blow up an asteroid of some arbitrary tonnage, say, a nice round billion tons, the planet is STILL fucked. Why?
Simple, and I repeat, a billion tons of gravel is still a billion tons of rock. Sure: there is more surface area and greater heating, BUT - all you have done is taken a catastrophic impact event of a billion tons of rock hitting several quintillion tons of rock (earth) into a billion tons of rock hitting a few million tons of air. At 25,000 mph, the kinetic energy of a billion tons of gravel will get converted directly into heat. So instead of a giant pinpoint nuke going off, it would turn a larger area of the planet into something like a broiler set on HIGH, and this heat event would last quite a long time, as anything that can burn will burn (explosively). Net effect: we all die.
Also: hitting it with a nuke ASSUMES it will *ALL* be reduced to gravel, and this isn't necessarily true. Many asteroids aren't that well put together, and there is a greater chance that by setting off a nuke on an asteroid, instead of a billion ton rock hitting in one spot, you could as easily end up with, say, four 200 million ton rocks all plowing into roughly the same little patch on earth AND 200 million tons of sand, gravel, frozen gasses, and other crap to turn the place into the solar system's biggest hibachi.
I can assure you what I speak is true - IANAAP (I am not an astrophysicist) but I have friends who are, and they all tell me the exact same thing:
blowing it up only works in (bad) hollywood movies.
You can't live outside the law of the conservation of mass and energy. A billion (or more) tons of rock is still a billion tons of rock, and when it's travelling at 25,000 miles per hour, it'll blow through 100 miles of atmosphere in about (but not a lot more) than a quarter of a second. BOOM. Game Over.
So, to re-iterate for the jillionth time:
BLOWING UP AN ASTEROID REALLY DOESN'T WORK. PERIOD. REALLY.
RS
Shoes for Industry. Shoes for the Dead.
Fuck that! Send all the nukes we have! It's not like if it fails we still have anything left to do with them...
No, they're not. The arguments in those posts assume that the rubble hits just as the main body would have; that's only true if the blast is very late. The arguments in those posts assume that 100% of the energy of the impact is radiated downward. That's not true at all. Those arguments assume that all of the rubble delivers all of it's kinetic energy as heat directed downwards. Neither is true - it's not all heat, and it's not all directed downwards. All of these assumptions are the consequence of simplistic thinking.
In short: blasting an asteroid of that size into dust means we get hit with some million H-Bombs equivalent, blasting the atmosphere away or heating it up to several thousand degree celsius. Only ocean life, plancton etc. and microbs will survive that.
This is incorrect. The reason that it is incorrect is because when a blast large enough to fragment a body of that size is applied, the body will alter its vector significantly. If the blast is applied to the side, and in a sufficient amount of time, the vector will cause the rubble to miss.
Getting an impact by a solid block causes earthquakes, an eruption, "nucelar winter" and tsunamies etc. However even some people might survive elswhere.
Yes. However, you completly miss the point. The objective here is to miss getting hit by either the block, or the majority of its fragments. That is quite aside from the simplistic - and incorrect - assumption that 100% of the kinetic energy will be delivered if the object is converted to rubble.
I understand those terms, likely you used them corectly. But: if you understand the terms as well, the formulars to calculate how big the "sideways momentum" might be, if a singel h-bomb makes close hit, are EASY. So you will figure you are wrong if you just enter the numbers.
Obviously, if we're talking about the same object we started talking about, we're not talking about "a single h-bomb." If you want to break an object the size of the "peanut" into 1000 fragments (other than one really big one and 999 really small ones) then you'll be using a lot more force than a single bomb can deliver. h-bombs aren't magic. Now: If instead you figure the force required to fragment the thing into more or less equal rubble, you will find that the forces imparted to the original vector are not insignificant, either from the blasts and/or from large parts of the object being turned into high-velocity gas and dust going in a new direction.
Plasma and shockwave: well, a shockwave moves with a speed about the sound barrier ( a small multiply). The impacting particles, in case of dust, are up to 50 times faster.
Speed is not the issue. How hard the air is, is the issue. Think about it.
I simply can not see how the shockwave of one of those particles should shield the earth against the following ones :D
Well, stick your face outside a jet cockpit at mach 1, and you'll learn. Well, your next of kin will learn. :) Or, shoot a single tiny 22 caliber bullet into an oil drum filled with water. Watch what happens to the lid. Shock waves are nothing to discount.
Especially as that wave moves in circles away from the impact point and not up behind the impacting body.
As you observed above, the speed that the shock wave travels isn't much compared to the incoming bodies. Therefore, the incoming bodies will run into the shockwaves. Rock hard air meeets rock. Bang. With the rock hard air between the result and the earth, mind you.
Finally: if the upper athmosphere gets heated up, like you think it will not harm us: it gets heated to about 3000 degrees. How long can you take a sun bath under a sky with that temperature in a distance/hight of just a few kilometers?
The issue isn't how hot a spot gets, it is, how many spots get that ho
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