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UN Mounts Asteroid Defense Plan Following Chelyabinsk Meteor
Philip Ross writes "Astronomers have warned that our planet is long overdue for a defense plan against catastrophic asteroid collisions. When it comes to deflecting Earth-obliterating celestial bodies, short of a superhero capable of punching the approaching rock back into outer space, there is no single force dedicated to stopping cosmic bullies from striking our little blue planet straight in the eye. That's why the United Nations said it will establish an International Asteroid Warning Group to intercept and divert dangerous asteroids."
Because nothing is as effective at deflecting tons of rock coming towards Earth at extremely high speeds as... a committee.
Cue American sovereignty tinfoilers in 3...2...
The main issue we've got is the lack of warning we have. Even a year is too late if you want to divert large lumps of rock.
Once you're going to divert something then you have to work out where its going to end up - no point diverting it from the earth this year, to have it end up crashing into something else which ends up sending 100 rocks at us.
And here's the same tired old argument that we see when a third world country plans a satellite launch. Oh noes ... they don't have enough toilets ... and while they are sorting that, they should just sit around for the next couple of hundred years doing nothing else!
The UN does have specific hunger and poverty eradication goals and organizations that look into those issues. See these:
http://www.unicef.org/mdg/poverty.html
http://www.un.org/millenniumgoals/poverty.shtml
That doesn't mean the UN shouldn't have unrelated committees/arms investigating other issues and see if something can be done to address those.
I don't think a strongly worded protest/condemnation and/or sanctions will be noticed by an incoming asteroid. ;-)
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UN should focus on basic / REAL people problems, not playing star wars.
1 - Being well fed doesn't stop meteorites.
2 - The UN's objective is to defend against basic/REAL threats against humanity (which essentially boils down to assuring world peace to avoid a third world war). Millions of people dying of hunger, sad as it may be, doesn't threaten the humanity unless those people also have an army with nuclear power.
3 - (the most important one) The UN is perfectly capable of doing several things at the same time.
the UN can send a diplomat in to space to negotiate with the asteroid
Politics is Treachery, Religion is Brainwashing
Thank you for your uninformed, knee-jerk anti-UN comment.
They did eradicate smallpox, you know.
The New Scientist had an article about this. If it's just big enough to destroy a city, but not to destroy the planet, the most practical solution would be to evacuate the city.
To me this looks like an agreement by the UN to help fund NASA's existing NEO program ( http://neo.jpl.nasa.gov/ ).
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we have preliminary numbers. Russia has been hit by potential city shattering meteorites twice in a hundred years. If the Tunguska event happened over a populated area it would no longer have been populated. If Chelyabinsk had entered at a slightly steeper angle, it would have been significantly worse. As it is, it entered at a shallow enough angle that it broke up high in the atmosphere and reducing the effect of the shock wave. We have a reasonable handle on the larger nation killing, and extinction causing, world ending variety. What we don't have is sufficient tracking data on the smaller city killers.
...an agency of the UNITED NATIONS.
http://en.wikipedia.org/wiki/World_Health_Organization
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Then we shouldn't do it. While your at it, please turn over all technology in your possession that didn't exist 200 years ago and, at the time, would have been considered impractical or impossible. Cell phones, automobiles, computers, implanted medical devices, plastics and synthetic fibers, electric lighting and refrigeration... to name a few items.
/sarcasm/ Oh yes, I forgot - the UN has prevented the US from invading literally DOZENS of countries, for fun and profit. In 2002, the UN put it's foot down, and firmly denied permission to invade Iraq. Yep, I remember now.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
http://en.wikipedia.org/wiki/Massive_Ordnance_Penetrator
If the big ass rock doesn't crack, you still ejected material in one direction at extremely high speed. Did you actually read my post? And, how many asteroids are pure nickle/iron?
And, what is this "100 mph" nonsense? We don't NEED to make any delta changes that drastic. Try to visualize this now. A quarter million miles out, there is a big rock aimed DIRECTLY at earth. It's going to take six weeks to get here. We detonate a warhead, which launches only a single ton of debris in a sun-ward direction, at extremely high speed. Your 200 ton rock is now 199 tons, which has absorbed the same amount of energy that launched the one ton of rock, well in excess of 1000 mph. That 199 tons is still going to come near earth, but it has six weeks to move OUTWARD from the sun.
Better still, to detect that threatening asteroid a million miles out, or multiples of millions of miles. The earlier you detect, the earlier you detonate, the larger the CUMULATIVE effect of even a very small change in course.
Unfortunately, It seems most people visualize a straight-on missile strike, as if they expect an explosion to just STOP the asteroid. We don't want to stop it - we merely need to deflect it a few fractions of a degree.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Bunker busters don't split the earth; they penetrate an outer shell to damage something squishy inside. Still, the 'digging' part of this is useful. This one goes 200 feet.
A quarter million miles out there is a rock traveling in excess of 30,000mph (YU55 was traveling at 29,000mph; Chelyabinsk was traveling 41,750mph). The earth is 8000 miles in diameter, so we need to move this rock 4000 miles in about 8 hours. We can consider that for each 30,000 miles it approaches us we need it to move 500 miles perpendicularly. That means with this rock 1/4 million miles away, we need to immediately give it 500mph velocity perpendicular to its approach. Given that acceleration takes time, the actual final velocity will be much higher.
Consider that the distance to the moon is 1/4 million miles; while to mars the distance is between 36 million miles and 250 million miles. Let's say we can see something as far away as Mars at 100 million miles--we're looking for a spec of space dust, it's hard to see. At 30,000mph that gives us 3,333 hours to move 4000 miles--about 1.2mph sideways instantaneously; however we're going to approach the rock at like 17,400mph (Space Shuttle Discovery's top speed), so 47,400mph approach gives interception at 2,109 hours with the rock about 36.7 million miles away instead of 100 million--2/3 of the time gone, leaving us 1224 hours to move 4000 miles, a good 3.25mph required.
So you need 3.25mph, or over time who knows? To move a 10,000 tonne (10 million kilogram) meteor like Cheylabinsk, a city-destroyer, you need to accelerate it more than that but let's go with 3.25mph over 1224 hours. F=ma, so 10,000,000kg * 1.45m/s / 1224hr = 3.3kgm/s^2. 3.3 newtons applied for a continuous 1224 hours.
The S-IC used 700,000L of RP-1 at 0.81g/mL and 1,305,000L of liquid oxygen at 1.141g/mL to produce 33MN of thrust for 150 seconds with 567,000kg fuel and 1,840,050kg of oxidizer (total payload: 2,407,050kg of fuel). If we divide that 33MN down by 10 million to 3.3N and then multiply that 150 seconds to 1224 hours, we need roughly .003 times as much fuel needed: 7,068kg
You need 7,000kg of fuel to deflect a city killer detected 100 million miles away moving at 30,000mph, in addition to launch fuel, and assuming you can spot and immediately deploy countermeasures. Or, yeah, use a nuclear generator to dig and throw rocks away.
At this point we're at "evacuate the city" territory. The risk and expense are bigger than the expense of building a city--and you'll have all that nickle-iron material to use too!
Something with 100 times as much energy will take 100 times the energy to deflect ... or more: if it's moving much faster, you'll need to apply a lot more force. A meteor moving twice as fast is moving faster than your probe, so it will reach your prior interception point before your probe.. you'll land on it when it's closer. If it's 10 times faster, you'll barely be off the ground; you have hours, not weeks. If it's 10 times as big, you only have to push it 10 times as hard.
And then there's the whole "it's hard to see something that small 100 million miles away" problem. It'll probably start weeks out, not months out. If it comes from the direction of the sun, or obscured by the moon, it could be invisible. A lot of non-obscured space rocks are invisible most of the time even when you know exactly where they are.
Good luck, Solar Jetman!
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