NASA Outlines Asteroid Deflection Program

An anonymous reader submitted a link to an International Herald Tribune story about NASA's answer to the movie 'Armageddon'. Specifically, they've outlined a plan to deflect a planet-killer asteroid. "In 1998, Congress gave NASA's Spaceguard Survey program a mandate of 'discovering, tracking, cataloging and characterizing' 90 percent of the near-Earth objects larger than one kilometer (3,200 feet) wide by 2008. An object that size would probably destroy civilization. The consensus at the conference was that the initial survey is doing fairly well although it will probably not quite meet the 2008 goal." With this tracking system in place, scientists are hopeful an intervention could be staged before any grim choices have to be made. Assuming they have the money and manpower needed for the effort, NASA has actually outlined a pair of procedures that dove-tail with each other: "First we would deflect the asteroid with kinetic impact from a missile (that is, running into it); then we would use the slight pull of a 'gravity tractor' -- a satellite that would hover near the asteroid -- to fine-tune its new trajectory to our liking. (In the case of an extremely large object, probably one in 100, the missile might have to contain a nuclear warhead.) To be effective, however, such missions would have to be launched 15 or even 30 years before a calculated impact."

Interventions

[dreamchaser]

With this tracking system in place, scientists are hopeful an interventions could be staged before any grim choices have to be made.

NASA has announced that they have gathered the mother, father, siblings, and close friends of asteroid YT8OJR in order to confront it about it's continued binge drinking and other self destructive behavior before it leaves more shattered lives in its wake. Unconfirmed reports show that the troubled asteroid could be close to cracking up. Hopefully the intervention will keep it from a collision course with disaster.

Re:

[Talgrath]

Wow, somebody's a racist.

Make things worse?

[CommunistHamster]

Can we have an accurate estimate of the probability of a specific impact 30 years in the future? What if we change the course of an asteroid such that it has a new, better chance of hitting us the year after?

Re:Make things worse?

[omeomi]

There was an interview with a guy on NPR concerning this...from what he was saying, the answer is basically, yes...things in space don't change direction unless something else hits them, so in theory, it is possible to predict an impact 30 years in advance. The main problem is that our ability to model trajectories isn't fine-grained enough to do so, yet.

Re:

[justthinkit]

things in space don't change direction unless something else hits them

By hit you also mean the hit of gravity from a close encounter, right?

Re:

[PaulDineen]

...such as Jupiter?
http://www.teachersdomain.org/resources/ess05/sci/ ess/eiu/jupitersrole/index.html [teachersdomain.org]

Jupiter acts as a big shield for Earth overall, but does its gravity alone occasionally throw a big honkin' rock our way (with no collision required)?

Re:

[omeomi]

Of course. Thing is, there's a whole lot of nothing up in space. For an asteroid to travel 30 years without coming anywhere near a large object isn't that difficult to imagine...

Re:

[Surt]

Sure, but we know where all the large masses in the solar system are, out to the orbit of Neptune. We can calculate their effects quite easily, and we do so all the time for our own spacecraft missions.

Re:

[solevita]

I think in this day and age the requirement for accurate estimates are outweighed by the desire to put nuclear weapons in space.

You can imagine Peter Sellars in the War Room on the phone to China explaining that the nuclear deterrent is to deter asteroids, and in no way is trying to arm space.

How would nuclear weapons work in outer space?

[mosel-saar-ruwer]

In the case of an extremely large object, probably one in 100, the missile might have to contain a nuclear warhead.

On earth, a nuclear weapon causes damage via its atmospheric shock wave - it's the motion [kettering.edu] of the air that causes buildings to fall down [or implode, or whatever].

Do we even know how a hunk of rock would react to the introduction of a bunch of alpha particles/gamma rays/x-rays/infrared radiation/etc? How would the the crystalline structure of the rock be affected? What models do we have that indicate the rock would shatter from an internal heat differential, rather than merely glowing very bright red for a while [assuming the rock even chose to absorb the heat energy in the first place, rather than just deflecting it off into the void of outer space]?

By contrast, underground detonations of nuclear devices are very benign events, and release vastly less energy than a small earthquake or a small volcanic event.

It's only the gaseous shock wave of an atmospheric detonation that causes damage to humans & their metropolitan areas - in the vacuum of outer space, with no atmosphere [i.e. with no gas, hence no gaseous shock wave], a nuclear detonation might not be that big of a deal.

Re:

[Anonymous Coward]

I don't think a nuclear weapon would prove effective if detonated near the object, however if the warhead penetrated the object (like bunkerbuster bombs do) and detonated the intense heat would vaporize the matter immediately surrounding it essentially turning it into atmosphere. This newly created super heated atmosphere would then escape though the hole that the nuke created essentially making short blast high intensity thruster. This improvised thruster would then hopefully push the asteroid out of the

Re:

[fireylord]

The issue with that is that it assumes the asteroid is one solid, stable rock. It's just as likely fracture the asteroid because it's a fragile structure made up of many objects not a solid object

Re:

[Firethorn]

Even that would be preferable to the impact of the large asteroid; Even if all the object still hits the earth, it'll do so more gradually. If it does so over the next 30 years of orbits, that's only 3% of the original object hitting each year. Smaller objects can be absorbed by our atmosphere far more readily than one huge one.

Re:

[Firethorn]

Umm... No worse than what you'd expect of a rock hanging around in the sun for millions of years without any radiation shielding other than itself?

Re:

[Firethorn]

It's not nearly as nasty as you might think, given that the particulate close enough to the detonation to become radioactive is also going to be the most dispersed. If it hits the earth at all it's likely going to be years down the road, meaning it'll be less radiactive, and the most spread out, meaning it'll burn up in the atmosphere, only detectable by the most sensitive of scanners, though it'll likely be lost in the noise of radiation that is the sun.

As for why rock in space would be more radioactive t

Re:How would nuclear weapons work in outer space?

[flyingsquid]

On earth, a nuclear weapon causes damage via its atmospheric shock wave - it's the motion of the air that causes buildings to fall down [or implode, or whatever].

Much of the damage caused by nuclear weapons, particularly hydrogen bombs, is actually from the intense heat released; the thermal energy is capable of causing severe burns miles from the point of explosion even after the air has absorbed most of the radiation (which is why, believe it or not, "duck and cover" isn't such bad advice). My suspicion is that you would want to detonate the bomb some distance above the asteroid; the heat would cause the surface of the asteroid to vaporize, and the gas jetted from the surface would shove the asteroid off course.

Empty space varies as N-cubed

[mosel-saar-ruwer]

My suspicion is that you would want to detonate the bomb some distance above the asteroid; the heat would cause the surface of the asteroid to vaporize, and the gas jetted from the surface would shove the asteroid off course.

Empty space varies as R-cubed, and the spherical effects tend to degrade as 1 over R-squared.

It doesn't take much of an R to make that asteroid look like a tiny, insignificant needle in the vast, overwhelming haystack of empty space.

Cf Derbyshire's critique of Whedon & the "n [nationalreview.com]

Re:Empty space varies as N-cubed

[zCyl]

Empty space varies as R-cubed, and the spherical effects tend to degrade as 1 over R-squared.

It doesn't take much of an R to make that asteroid look like a tiny, insignificant needle in the vast, overwhelming haystack of empty space.

Without doing any calculation, I presume there's an optimal distance away which is somewhere around a quarter or a third of the asteroid's diameter. Presumably someone would simulate this properly before launching a nuke all the way to an asteroid.

Re:

[ArbitraryConstant]

"Do we even know how a hunk of rock would react to the introduction of a bunch of alpha particles/gamma rays/x-rays/infrared radiation/etc? How would the the crystalline structure of the rock be affected? What models do we have that indicate the rock would shatter from an internal heat differential, rather than merely glowing very bright red for a while [assuming the rock even chose to absorb the heat energy in the first place, rather than just deflecting it off into the void of outer space]?"

Most of the he

Re:

[salec]

Do we even know how a hunk of rock would react to the introduction of a bunch of alpha particles/gamma rays/x-rays/infrared radiation/etc? How would the the crystalline structure of the rock be affected? What models do we have that indicate the rock would shatter from an internal heat differential, rather than merely glowing very bright red for a while [assuming the rock even chose to absorb the heat energy in the first place, rather than just deflecting it off into the void of outer space]?

Well, actually

Re:

[maop]

Effects of nuclear explosions [wikipedia.org]

The interaction of the X-rays and debris with the surroundings determines how much energy is produced as blast and how much as light. In general, the denser the medium around the bomb, the more it will absorb, and the more powerful the shockwave will be.

The energy of a nuclear explosive is initially released in the form of gamma rays and neutrons. When there is a surrounding material such as air, rock, or water, this radiation interacts with the material, rapidly heating i

Re:

[salec]

All Sun-orbiting cellestial bodies have velocity between solar "first cosmic speed" (circular orbiting speed) and solar "second cosmic speed" (escape velocity). In order to get rid of dangerous ones, we need to slow them down (e.g. by retro-rocket braking) so that they would fall on Sun, or speed them up to solar "second cosmic speed" so that they leave our system entirely, not try to swing them sideways, into an unpredictable, wobbling orbit. What we choose to do depends on what is "cheaper" (energy-wise),

Ladies and Gentlemen, I present to you: CTDF

[Anonymous Coward]

CTDF (Chair Throwing Defense System) is a highly effective method of deflecting incoming, civilization-threatening asteriods which are on collision course with our blue planet. The procude is as follows:

1. Fly satellite up there
2. Make satellite paint a big-fat google logo on the asteroid
3. Let Steve Ballmer have a look through telescope
4. Provide him with practically insufficient supply of chairs
5. Wait
6. Danger avoided

Re:

[solevita]

insufficient

I don't think that word means what you think it means.

Re:

[Anonymous Coward]

Ahh, thanks for pointing that out -- I meant infinite. Didn't feed my babelfish today.

Re:Ladies and Gentlemen, I present to you: CTDF

[LaughingCoder]

A slight modification:

1. Tell Steve Ballmer the asteroid is a threat to Microsoft
2. Disable all space-based anti-ballistic-chair defenses
3. Wait
4. Danger avoided

Re:

[dotgain]

You are disabling all space-based anti-ballistic chair defenses.
Allow/cancel?

Re:

[kalirion]

4. Provide him with practically insufficient supply of chairs

Are you sure that a practically insufficient supply of chairs will be enough?

Get a life

[Aaron Isotton]

Humans (in some form or other) live on earth since 4 million years, and no killer asteroid has hit this planet since. How crazy do you have to be to think that an asteroid is a real threat for humankind? *shakes head*

Re:

[aldo.gs]

Come on, now. Even in the summary they mention the word 'Civilization'. Rings any bells?

Re:Get a life

[JonathanR]

So one US government administration is trying to save civilisaiton, and the other US administration seems hell bent on destroying it.

Re:Get a life

[omeomi]

How crazy do you have to be to think that an asteroid is a real threat for humankind? *shakes head*

Well, unless you've seen any dinosaurs lately, an extinction event has happened in the Earth's past at least once. Yeah, the chances of it happening again in our lifetime are infinitesimally small, but the consequences of *not* deflecting an asteroid if it comes our way are especially dire. I, for one, am all for the "just in case" planning in this regard.

Re:

[Aaron Isotton]

Yes, that was 65 million years ago. Way before humanity.

http://en.wikipedia.org/wiki/Cretaceous-Tertiary_e xtinction_event [wikipedia.org]

"Just in case" planning for this is just stupid and a waste of time and money. There are many other things (wars, diseases, maybe terrorism) which are much more likely to destroy civilization as we know it. It'd be better to invest more in that than to play Armageddon.

I realize that a single asteroid may wipe out humanity, but the probability that this is what will put an end to civiliza

Re:

[Tenebrarum]

It'd be better to invest more in that than to play Armageddon. That's what the dinosaurs thought, and look where it got them.

Re:

[an.echte.trilingue]

You are probably going to die of something other than an automobile accident. Does that mean that the auto industry should stop spending billions on crash tests and safety features (airbags, crumple zones, ABS, seatbelts, etc)? No.

True, there are other, more pressing issues in the world, and so the asteroid thing should be on the back burner, but that does not mean that we should turn the back burner off. People can multi task, so lets do it.

Re:Get a life

[Yvanhoe]

There are many other things (wars, diseases, maybe terrorism) which are much more likely to destroy civilization as we know it.

Considering how well money has been spent on projects like "the war to end all wars" and the "war on terrorism", I would say that a project to deflect asteroids looks very wise in comparison. Whereas, I agree, the research on diseases is an important and underfunded domain (yes, I'll consider it underfunded as long as I have a life expectancy inferior to two centuries). Anyway, it's "just" a few millions dollars spent on watching pebbles in the sky, an activity that could be useful and do no harm, and it goes back into the economy anyway...

Re:

[Planesdragon]

yes, I'll consider it underfunded as long as I have a life expectancy inferior to two centuries

The elite of the Renaissance spent the wealth of nations funding alchemists who promised to discover the Elixer of Life; throwing money at a problem will not cause a 300% increase in our adult lifespan.

Re:

[ColdWetDog]

The elite of the Renaissance spent the wealth of nations funding alchemists who promised to discover the Elixer of Life; throwing money at a problem will not cause a 300% increase in our adult lifespan.

Maybe not, but I wish I could write grant proposals like that.

Re:

[Raenex]

Anyway, it's "just" a few millions dollars spent on watching pebbles in the sky, an activity that could be useful and do no harm,

Agreed.

and it goes back into the economy anyway...

Err, disagree. I see this argument made in favor of any pet project. There's a real opportunity cost funding any project. For something like the moon shot, you can argue that a lot of good technology came out of that and helped the economy. Searching for rocks in the sky? Not so much.

Re:Get a life

[leenks]

Oh come on - how crazy do you have to be to think this is true? Everyone knows there were no dinosaurs! Fossils are merely artifacts put there by God to test our faith. Don't you "scientist" types know *anything*?

Yeah, but...

[TheVelvetFlamebait]

...with the budget they're using, they could probably buy at least one cup of coffee for everyone in the world. Now how can you justify it?

Insurance

[Etherwalk]

It's called `insurance' or `risk management.' While it's true that insurance companies tend to get cast in a negative light because, well, their accountability and complexities are terrible and they tend to screw people over, the having of insurance is still important. Just because the odds of something occuring are small doesn't mean that you shouldn't plan for the possibility of disaster. We had the dinosaur extinction, and we've had near-earth impacts that have wiped out hundreds of thousands of squar

Re:

[Frumious Wombat]

Take the previous poster's link to the U. Arizona website, http://www.lpl.arizona.edu/impacteffects/ [slashdot.org]">ImpactE ffects, plug in some numbers, take the averages for density, angle of impact, and verlocity, and get the following results at 200KM/124 Miles: (this would be what happens in Pittsburgh/Philly if you splat Harrisburg)

Dense rock, 500M, sedimentary hit: not a lot at 124 miles, at 62 miles 2nd degree burns and trees ignite Dense rock, 1000M, sedimentary hit: at 124 miles same as 62 miles above. a

Re:

[Beryllium Sphere(tm)]

>How crazy do you have to be to think that an asteroid is a real threat for humankind? *shakes head*

You have to be crazy enough to realize that civilization is more fragile than the species is, and crazy enough to realize that if an explosion the size of Tunguska or even smaller goes off near the India-Pakistan border the world will be breathing radioactive fallout for years.

You also have to be crazy enough to do basic math and work out the odds of intolerable damage on a time scale of hundreds or thousa

Riffing off Tunguska

[benhocking]

You bring up a valid point, but it actually raises more questions than answers, IMO.

1. The NASA program isn't set up to detect asteroids small enough to "only" cause a Tunguska event.
2. If we did detect it before it happened, it would probably be with only enough time to evacuate the area. Which is a lot better than doing nothing, mind you.
3. What kind of overreaction would there be if the world knew a Tunguska-size asteroid was heading our way?

http://www.lpl.arizona.edu/impacteffects/

[Anonymous Coward]

1 km could be a civilisation killer? don't think so: http://www.lpl.arizona.edu/impacteffects/ [arizona.edu]

Your Inputs:
Distance from Impact: 250.00 km = 155.25 miles
Projectile Diameter: 1000.00 m = 3280.00 ft = 0.62 miles
Projectile Density: 3000 kg/m3
Impact Velocity: 40.00 km/s = 24.84 miles/s
Impact Angle: 80 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock

Energy:
Energy before atmospheric entry: 1.26 x 1021 Joules = 3.00 x 105 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.8 x 106years

Atmospheric Entry:
The projectile begins to breakup at an altitude of 67700 meters = 222000 ft
The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 39.8 km/s = 24.7 miles/s
The impact energy is 1.25 x 1021 Joules = 2.98 x 105MegaTons.
The broken projectile fragments strike the ground in an ellipse of dimension 1.1 km by 1.08 km

Major Global Changes:
The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.

Crater Dimensions:
What does this mean?

Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.

Transient Crater Diameter: 17.2 km = 10.7 miles
Transient Crater Depth: 6.08 km = 3.77 miles

Final Crater Diameter: 25 km = 15.5 miles
Final Crater Depth: 0.78 km = 0.484 miles

The crater formed is a complex crater.
The volume of the target melted or vaporized is 10.9 km3 = 2.62 miles3
Roughly half the melt remains in the crater , where its average thickness is 47.1 meters = 154 feet

Thermal Radiation:
What does this mean?

Time for maximum radiation: 0.54 seconds after impact

Visible fireball radius: 16.6 km = 10.3 miles
The fireball appears 15.1 times larger than the sun
Thermal Exposure: 6.78 x 106 Joules/m2
Duration of Irradiation: 280 seconds
Radiant flux (relative to the sun): 24.2 (Flux from a burner on full at a distance of 10 cm)

Effects of Thermal Radiation:

Much of the body suffers third degree burns

Newspaper ignites

Plywood flames

Deciduous trees ignite

Civilization

[Beryllium Sphere(tm)]

That megatonnage is equivalent to a few thousand Trident submarines. Granted that most of it is wasted making ground zero even more incandescent, but a lot of the ejecta and the smoke from incinerated cities will stay in the atmosphere and create a non-nuclear "nuclear winter". Plus odds are 2-1 that it will hit an ocean, and remember that most of the world's population lives near coastlines. Ocean strikes are also more effective at coupling impact energy into the atmosphere.

At least we'd have spectacular s

Re:

[imsabbel]

Take a closer look at the data, and read between the lines:
3*10^5 megatons== More than all nukes of the world together.

In that distance (250km), its enough radiation to set everything but a swamp to fire.
-> you get half a million km^2 of burning land.
Add to this the evaporation of km^3 of crust material, and you will increase the particle density in the stratosphere by orders of magnitudes.
Nuclear winter, anybody?

if the boulder hits a ocean (likely), the water vapour would do that job nicely, too.
Also th

Re:

[Surt]

And of course, helpfully omitted from that analysis was atmospheric dust, which is the real civilization ending threat.

Re:

[khallow]

It's interesting how quickly one exhausts the descriptive part. I dropped a 10km hunk of metal at 50 km/s for the FUN of it at 100 km away. Sure, I imagine that 22,000 km per hour winds will strip leaves off that tree that caught fire. And you'd pick up 3rd degree burns on the parts of your body that weren't instantly vaporized in the fireball of which you are now part. And by golly, that earthquake is something at magnitude 10.7. But it's not that important compared to the 12 km of ejecta that's about to b

The converse...

[SethHoyt]

The same technology used to deflect asteroids away from Earth can be used to steer them towards us. Who would want to do that? Well, the military, terrorist groups, anyone with the financial backing and desire to destroy entire regions of the planet. In my estimation, we're more likely to be struck by an asteroid intentionally directed here than by chance.

It would actually be much cheaper to redirect an asteroid for this purpose than it would be to acquire and deliver nuclear weapons. Another reason this ma

Re:

[bmgoau]

Im sorry, but after reading your first paragraph i really must ask:

Are you doing crack?

Re:

[Oswald]

This is an interesting case. Naturally, your first response to OP's allegation that some people in the government would intentionally risk causing the end of humanity is: Nobody is crazy enough to do that. But then it hits you: Obviously this bozo is.

So now I don't know exactly what to think.

Bringing Them *Closer*

[evought]

This is an interesting case. Naturally, your first response to OP's allegation that some people in the government would intentionally risk causing the end of humanity is: Nobody is crazy enough to do that. But then it hits you: Obviously this bozo is.

So now I don't know exactly what to think.

Well, unfortunately, I think the GP is not the only crazy that would think like this. There are a lot of extremists out there that think the Earth needs a good cleansing and are not afraid to die themselves. Whether they could ever get their hands on an asteroid steering system is another question.

Crazies aside, there is a good reason to steer an NEO closer to Earth. It would make a great resource if it could be coaxed into orbit, especially if it contained smeltable metals or was big enough to serve as

Re:

[Hotawa Hawk-eye]

Before we start nudging asteroids into orbit around Earth, we should practice putting them in orbit around Mars. If we mess up and the asteroid impacts Mars, the energy released by impact will thaw any ice that may be trapped below the surface, thus helping a little bit with terraforming the planet, rather than slamming into Earth.

Re:

[Planesdragon]

It's a far-reaching scenario, but the government hasn't done a shred of work to deserve the trust you seem to place in them to "at least have that border they'll never cross"; actually, they've shown quite the opposite.

the United States has detonated exactly two WMDs in anger. This was done so because the projected loss of life from the war it averted was significantly higher than that of the WMD attack. And the gov't took immediate claim for it, just as they've taken immediate claim for any major militar

Re:

[bmgoau]

I originally asked if the head poster was on crack.

I take tha back now

Are you on crack?

Im getting slightly confused.

1. The Holocaust is the name given to the jewish extermination in WW2, by definition it is a noun and cant be used an as adjective to describe the events in WW2.

2. Im not sure if your for or against Asian people from that sentance, but frankly many of my clostest friends, and yeh i live in Australia are from Korea, Japan and other asian nations. To me they are simply as human am. By which i me

Hey

[okinawa_hdr]

I've seen Armageddon and it just isn't possible unless you bring in the world's best deep core oil drillers, ok?

Why not use it?

[dattaway]

Since launching materials in space costs money, why not mine these potential resources and milk them for all they are worth? Lots of iron, water, and other useful minerals can be extracted. Need a radiation and particle shield for the space station? Tow that rock on over there and latch onto it! Those rocks are floating gold mines in space.

Re:

[MollyB]

Great Idea, but we wouldn't even have to tow it (given enough lead time) if we just built a rocket engine pointing "downwards" and fuel it with the hydrogen and oxygen we extract from the (presumed) water ice? Then it could be pointed anywhere... 8)

Re:

[CommunistHamster]

There are many different kinds of asteroid. Some are ore-bearing, but some are just rock with a negligible mineral content.

Re:

[Orange Crush]

Since launching materials in space costs money, why not mine these potential resources and milk them for all they are worth?

Oh, I have no doubts asteroid mining will one day be a huge driving force for the commercialization of space. Once it's practical and cost effective, we'll do it. But regardless of the value of an asteroid's material composition, it is decidedly *not* useful if it's headed right for us on a collision course. Nudging such an asteroid just enough to be captured into Earth orbit ra

Re:

[MousePotato]

I've been thinking the same thing for a long time. However, considering that when you decide to mine a given asteroid for its resources you've probably already surveyed it and decided that its worth doing. One that's headed your way for an impact isn't always worth mining.

That said, I think it would be interesting if we could design a way to capture Apophis on one of its visits. Not for mining mind you, but for use with building a space tether/elevator. At ~250 meters its almost a gift in terms of an anchor

Asteroid Radar System?

[vbwyrde]

I've always wondered if we could create a device that does the following:
1. Go into a position above the plane on which the planets rotate around the sun so it looks "down" on the solar system.
2. flash a bright light of a specified color every day at a certain time.
3. read back the ping signature of the solar system's objects with a light sensitive camera.
4. plug the changes into a computer.
5. calculate trajectories of all objects.
6. determine exactly which ones are on a bee-line for earth.
7. continue to mo

Re:

[Anonymous Coward]

Asteroid Radar System? Sounds like a half ARSed idea to me...

Re:

[drgruney]

Dude... the Universe is flat. It rests on the back of a giant turtle.

Re:

[deoxyribonucleose]

Well, the inverse square law plus the low albedo ( http://en.wikipedia.org/wiki/Albedo/ [wikipedia.org]) of http://www.aanda.org/articles/aa/full/2002/39/aah3 638/aah3638.right.html/ [aanda.org] most asteroids would necessitate an incredibly bright "light". Anyone feel like whipping out a napkin to do some calculations? I doubt if the visible spectrum would be better than radio wavelengths (after all, we're mainly after large objects, right?). I wonder what the design restrictions would be for a radar which has to wait several hours fo

Re:

[vbwyrde]

Thanks for the thoughts. What about just taking a motion picture of the objects as they move. Perhaps by doing a kind of strobe effect, say one pulse per second for one minute? This should provide something like a dash-dot effect so that speed and trajectory could be calculated. As for the visible light, I see what you mean. Perhaps radio waves at various frequencies? As for the economic factor - Earth-based telescopes are more economic unless they do not do the job sufficiently and as a result we get

Re:

[vbwyrde]

A - I suppose the position of the satellite would not have to be stationary so long as it's position could be determined with accuracy so that as the position changes the data could be correlated to the actual positions of the objects being tracked. It could be set in orbit around the sun. The objective of getting off the planetary orbit plane is to get an overview shot so that the sun, earth and moon would not obscure the view of asteroids. The photographic equipment, of course, would have to incorpora

I have faith in NASA for this mission

[JackMeyhoff]

Crashing into things is their speciality. However this gravity satellite is a bit fluffy. Since they seem to place money into the equasion, I say let the managers sit on the surface and count the pennies since thats obviously way more important than their asses.

Re:

[zippthorne]

There's nothing fluffy about a gravity-satellite. Except that their vision has only one, directly above the asteroid.

Since they're continuous thrusters, gravity tug doctrine should be to put the tug in halo orbit, and put more than one. Many relatively small launches are easier than one big launch after all, and they can be replaced as they fail without losing 100% thrust. The orbit would also mean that the exhaust would be less obscured by the payload.

The real question

[name*censored*]

Are we going to stop it _BEFORE_ or _AFTER_ it destroys Paris? Also, 15-30 years is a bit longer than usual, it normally only takes 112 minutes or so..

Funding?

[j00r0m4nc3r]

Who's going to fund this, and does that organization immediately become the supreme planetary overlords for having successfully saved the entire planet from complete destruction?

Bruce Willis

[bryan1945]

Come on, all we need is 3 weeks and Bruce Willis and his drilling buddies to defeat any asteroid. Geez, don't any of you watch the historical videos?

Re:Bruce Willis

[necro81]

Ya know, Armageddon (the movie) [wikipedia.org] cost about $140 million to make. For that same budget, we probably could have finished a very good survey of any Near-Earth Asteroids, create a detailed mitigation plan, and start building prototype hardware to send up. You probably could even get Jerry Bruckheimer to film an overly dramatic documentary filled with lots of sound effects in space and slow-mo hero scenes.

Re:

[tbischel]

Do you think you could get movie goers to shell out $553,709,788 to watch said documentary, which they would later lambast as the unholy spawn of The Dirty Dozen and Con Air? No? Well then, maybe Armageddon was money well spent.

Re:

[PaulDineen]

"Geez, don't any of you watch the historical videos?" You meant to say "the historical records" (http://imdb.com/title/tt0177789/ [Galaxy Quest]) Also, there's a fatal weakness in in the "Armageddon" arguments put forth here -- no assurance that Bruce Willis will still be alive thirty or so years henceforth (Long May He Live).

Re:

[bryan1945]

Sorry about that- just recalling off the top of my head!

Bruce? Nah...

[Gazzonyx]

What we need is Chuck Norris; he wouldn't even have to karate kick it... A single 'stare of death' and the astroid would change its own trajectory and tell its friends not to 'come around these parts' of the solar system.

Ignoring objects 1km across?

[HungSoLow]

Are they ignoring potential threats less than 1km in diameter? Are we to believe that an asteroid 999 meters in diameter will be harmless? Such folly! Perhaps NASA will make a meters / feet conversion error and we'll all be screwed.

Re:

[ArbitraryConstant]

They're going for 90% of all bodies 1 km across. They don't ignore smaller bodies (indeed, many have been found), it's just that a) smaller bodies are harder to see and b) there's way, way more of them. So for example, you might have 90% of 1 km bodies, 60% of all 900 m bodies, 30% of all 800 m bodies, and so on. Whatever the actual numbers are (I just made those up to illustrate the point), the goal is to locate the civilization-enders first, with progressively less threatening bodies being located later.

stupid idea from NASA

[FudRucker]

NASA has to make it more difficult than it has to be...

a plausable idea would be to use a nuclear bomb, not to destroy the asteroid or meteor but to detonate the bomb before it gets too close leaving the asteroid or meteor mostly intact, the blast wave from the bomb can be strong enough to push it out of the way...

Re:

[SteveM]

... the blast wave from the bomb can be strong enough to push it out of the way...

And what exactly does this blast wave consist of? The ether? Phlogiston? Cowboy Neal?

SteveM

Re:

[FudRucker]

good question, i personally never detonated a nuclear bomb in space, but i am pretty sure something that powerful will have a lot of push to it...

Re:

[SteveM]

In a vaccum, no one can hear you scream.

Nor is there anything to push against.

Thus the need to detonate the device on or in the asteroid itself.

SteveM

track .... line it up and ....fire

[ashwinds]

Ooops - wrong direction.....

A few more ideas for NASA...

[Adeptus_Luminati]

A few more ideas....

1) Assuming at least some of these asteroids will be passing Earth before they come back 100+ years from now (or however long) and then actually hit the Earth. Why not, as they are passing by, specifically as they have *passed* the Earth, nuke them from behind?

2) Same idea as #1, but instead get some modified HUGE rockets with robotic modifications to fly up to the asteroid, and then auto-magically grapple onto the 'Earth/rock' base of the asteroid, and then tilt to a different direction

Re:

[iggymanz]

heh, there's no end of ways an illusionist could produce your Mysore miracle. it's a hoax, honest.

Re:

[Adeptus_Luminati]

Not when the medal sits on my hand untouched by anyone else for 4 minutes straight producing a volume of liquid over 5 times the size of the medal itself, without the medal deteriorating at all (i.e. some sort of chemical reaction)... AND the output is edible rose scented honey!

I'd like to see you pull that one off.

Adeptus

Re:

[Adeptus_Luminati]

See picture of the 2 medals here, at the top of some person's hand. The medal pours out liquid honey filling the ENTIRE cupped hand (many times the volume of the medal itself), and if you let it sit there it would overflow the hand and start dripping on the floor.

http://www.saibaba.ws/images/miracles/Halagappa2.j pg [saibaba.ws]

Launch vehicle?

[caffeine_monkey]

Does NASA even have a rocket capable of intercepting an asteroid with something as heavy as a gravity tractor? They have some spare Saturn V rockets sitting around?

What's the hurry?

[Beryllium Sphere(tm)]

The thing about space is that small pushes over long times can work better than splashy big short ones.

Why bomb the asteroid when you could keep ion engines running for decades instead? Or maybe find some point in its orbit where it's going between two heavy bodies and a small change will tip it one way or the other and make a big difference?

Re:

[iggymanz]

real existing ion engines have thrust appropriate for a small payload over years, a kilometer wide ball of goop is going to need something hugem and detecting a collision fifty or hundred years before it happens isn't possible right now

Re:

[TimSSG]

The problem is the asteroids are almost always spinning so anything mounted on it what be thrusting in many different directions if on all the time. If, it was only firing part of the time a low thrust ION engine would most likely not do it soon enough. Also, I am not to sure if the on board computers would be able to calculate when to fire.

Note: Stopping the asteroids from spinning is not easy and would take time that may not be available.

Tim S

Funding?

[sumdumass]

I thought NASA was just complaining that it didn't have funding to do something like this.

Was that just a build up to make them look more important when this got released or did they find funding from their Doom and Gloom apropriations aproach?

OR maybe all the discusion NASA not being able to fund [slashdot.org] this exact program was sparked because someone didn't know what was going on? The government doesn't work this fast in approving funding so how could it be possible for them to all the sudden have it now? Especial

Meteor

[garlicbready]

I think the real question on every one's mind is
by the time we actually discover one of these things on course with the earth
will sean connery still be alive to save the day?
http://en.wikipedia.org/wiki/Meteor_(film) [wikipedia.org]

The timing of the funding...

[mi]

"In 1998, Congress gave NASA's Spaceguard Survey program a mandate of 'discovering, tracking, cataloging and characterizing' 90 percent of the near-Earth objects larger than one kilometer (3,200 feet) wide by 2008. [...]

Interestingly, the movie Armageddon [imdb.com] also came out in 1998...

Pardon me, but I'm skeptical. Earth had no civilization-killing encounters for thousands of years — no, the Tunguska-meteorite does not qualify, not even if it landed in Paris (the center of civilization at the time). The

Whoops?

[capebretonsux]

Maybe I'm just pessimistic, but I envision the following coming out of this...

We succeed in diverting it, and 15 years later we all sigh in relief as the asteroid passes by. The same year, we experience first contact, and realize where the asteroid is now headed.

First message: "You assholes."

Off Topic

[Anonymous Coward]

This post comes up every once in a while. I always find it really amusing. Slashdot is essentially a trade magazine; it targets and draws IT professionals, usually a very high-paid group of people and not a group likely to live in their parent's basements. Then there is somebody who takes the time to sit around late Friday night/Saturday morning, and hit the refresh button over and over until he can get the first post (ie, somebody without a job, a girlfriend, or probably many friends) and uses it to accuse a community of well paid professionals of living in their parents basements.

Re:

[Surt]

Wow, I think you're being generous. I had always assumed the grandparent was some homeless person with serious mental problems sneaking into a library or cybercafe.