Asteroid 'gives Earth a close shave' on Monday

[cameron marical]

Not the stupidest idea, no (that's a very high bar), but...

 

I'm not really clear on what you're describing. If it's just a laser tripwire, then objects would only be detected if they passed directly between two stations, which would make it pretty much useless, considering the distance involved (Imagine a cage with bars 100 million miles apart. What can it hold?). And even if that weren't an issue, say if you could somehow detect anything that passed through a plane defined by three stations, there's still at least two more problems. One, getting them out there (where "out there" is defined as far enough away from the Earth to offer good enough warning to actually do something about it, let's say a fairly arbitrary minimum of 500 million miles), and two, getting them into orbits where they all stay put relative to one another and to the Earth (or at least the Sun, if they're far enough away). And even if all of this is possible, you still have to show how it's potentially easier and/or more effective than looking around with telescopes.

 

So yeah, screw me and keep thinking, but remember that it is the approval of curmudgeonly naysayers that gives new ideas legitimacy.

 

ok, ya, i know. your right about the part with the cage, so maybe you could have multiple lasers shooting at different angles wich have receivers, wich also have lasers shooting in other directions{ to receivers wich have the more lasers and different directions } , and before you know it, just do it over and over again, and you have something that warns us about asteroids that are of threatening size, and ignores the little ones, or catches them with only one laser, we can judge the size by how many disruptions there are.

 

as for the staying in one place, well, there is no gravity in space, so unless theres something like a meteor rock wich knocks one out of normal floating location,{wich, i know, would screw everything else up, like a chain of reacitions, but i think that that can be solved}, then i think were good.

 

the screw you thing was kind of just a joke man, not realy to offend anyone...

[ennui]

Reading this thread is making me wanna watch Deep Impact.

[Sisyphus]

ok, ya, i know. your right about the part with the cage, so maybe you could have multiple lasers shooting at different angles wich have receivers, wich also have lasers shooting in other directions{ to receivers wich have the more lasers and different directions } , and before you know it, just do it over and over again, and you have something that warns us about asteroids that are of threatening size, and ignores the little ones, or catches them with only one laser, we can judge the size by how many disruptions there are.

 

I don't think you're appreciating just how big an area we're talking about and how many "receivers" you'd need. In order to catch something at least 500 million miles away, you're talking about a net with an area of about 3 quintillion square miles (3,000,000,000,000,000,000).

 

well, there is no gravity in space,

 

This is very incorrect!

[SH3RL0CK]

There is the additional problem with the tripwire theory that if something DID pass through the laser, you still would not know if it were headed for the earth, or away from the earth.

[Airbrush]

Forget the tools.

If the thing is water tight, and the door opens inwards, it should open soon enough without any assistance.

 

Then the escape hatch should be a sliding door!

 

The story at the top of this thread said that the object was discovered only 2 days before it passed by (seen on Saturday and flew by on Monday). Can coastal areas be evacuated in less than 2 days? If I had a beach house I would be skeptical about the prospects for a safe escape to high ground. Many areas have no high ground nearby. A Tunguska-sized impact in the middle of the Pacific may cause waves that are so massive that all coastal areas would be buried so deep in debris that there would be no way to exit an underground shelter. The shelter would only ensure survival from smaller impact tsunamis, but it may be your ONLY chance. For all we know, it can happen next week!

Edited March 5, 2009 by Airbrush

[DrDNA]

There is the additional problem with the tripwire theory that if something DID pass through the laser, you still would not know if it were headed for the earth, or away from the earth.

 

If some detection gizmo was so sophisticated that it imposed a web-like bubble of trip-wire lasers around the earth, millions of miles in diameter, calculating velocity and direction would be trivial in comparison.

 

I think that the main problem here is the choice of lasers; which by nature do not encompass great volumes of space.

What might be more viable than lasers would be a bunch of satellites in orbit, like GPS satellites, emitting radio waves or microwaves outward.

 

GPS satellites: at least six satellites, orbiting at 22,000 km, are always within line of sight from almost everywhere on Earth's surface.

 

In much the same manner that earth-bound location and speed can be accurately triangulated from any GPS receiver, the location and speed of any near earth objects should also be able to be determined a la radar: by bouncing the microwaves or radio signals off of any objects that come within range.

 

Again, I am talking about projecting the radio waves or microwaves outward and not inward.

 

Of course, if you wanted to focus detection inward, the satellites would need to be VERY FAR out into space to detect the anything in a reasonable time frame to be of value...probably too far to out to maintain a stable orbit around the earth.....

 

And maybe a land based system would be cheaper and more powerful anyway.......

 

On second thought, maybe lasers could work if they are able to raster scan (with mirrors?) volumes of space quickly enough. That I do not know.

 

...as for the staying in one place, well, there is no gravity in space, ......

Gravity is abundant; they can't hear you scream in space.

[Sisyphus]

But what's the effective range of omnidirectional radar? Not far enough to be useful in this case, surely?

[Airbrush]

Dr.DNA quote: "What might be more viable than lasers would be a bunch of satellites in orbit, like GPS satellites, emitting radio waves or microwaves outward."

 

That sounds good. Something like an outer space radar network of satellites. It can start with just a few satellites and then increase in number and improved coverage as money becomes available. The motion-sensing radar could make sweeps of broad areas of space.

 

Most NEOs travel on the plane of the solar system, so that would vastly reduce the coverage needed, as compared to the GPS system.

Edited March 5, 2009 by Airbrush

[Baub]

Wasn't the "Star Wars" project of the Reagan administration designed to detect and perhaps defend against, not only ICBM, but NEO threats? I was under the impression that Reagan could not push it through due to funding. Was it actually a lack of scientific feasibility? Also, sorry to sound facetiuos, but maybe with all the space debris we have up there these NEO threats will will be deflected away from earth when they start colliding with all the garbage?????????

[Airbrush]

The Tunguska-sized object raced by Earth at 1:44pm GMT on Monday. Even if it was discovered at 1:00am GMT on Saturday, that gave us only 36 hours notice..... at the most!

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Wasn't the "Star Wars" project of the Reagan administration designed to detect and perhaps defend against, not only ICBM, but NEO threats? I was under the impression that Reagan could not push it through due to funding. Was it actually a lack of scientific feasibility? Also, sorry to sound facetiuos, but maybe with all the space debris we have up there these NEO threats will will be deflected away from earth when they start colliding with all the garbage?????????

 

Even the most massive satellites in orbit would be nothing compared to even a very modest-sized NEO, which will pass through the space debris like a hot knife thru butter!

Edited March 5, 2009 by Airbrush
Consecutive posts merged.

[Baub]

A while back, using a missle, the US Navy successfully shot down a small satellite as is plummeted back to earth. I realize this was a very small scale compared to what you are describing, but is it likely that the Department Of Defense possesses the missle power to deflect a large object?

[SH3RL0CK]

A while back, using a missle, the US Navy successfully shot down a small satellite as is plummeted back to earth. I realize this was a very small scale compared to what you are describing, but is it likely that the Department Of Defense possesses the missle power to deflect a large object?

 

Deflecting an asteroid is a daunting task. I do beleive there was a project a while back called "Manhattan" where a new and very powerful explosive was developed utilizing the energy released by nuclear fission. Later refinements were able to utilize the energy released by nuclear fusion (which unlike fission, has no known limit to the energy that can be released). It is possible that this might just have sufficient power to deflect the object. Or not.

 

There are other ways to deflect the asteroid. For example, the gravitational attractor...I would suggest a google or wiki search.

[Airbrush]

I like the idea of exploding a nuke next to the object, not too close to break it into pieces, but just close enough to heat up one side. This will cause outgassing (or something like that) from the object. The reaction would nudge it a little and hopefully enough.

 

But all those ideas are useless when you don't know it exists until less than 36 hours before impact!

Edited March 5, 2009 by Airbrush

[Baub]

I did a google on the gravitational attractor; it lead me to aan article in NewScientist July 2008 by David L Chandler in which he discussed the theory of a gravity tractor. It said that NASA had performed experiments that showed the weak gravitational field from a nearby space ship could have enough of an influence on an object 130Km wide to deflect it from earth. I would have thought that a much larger gravitational field would be required. Sounds like exlploring gravity based defenses is where we should be.

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I like the idea of exploding a nuke next to the object, not too close to break it into pieces, but just close enough to heat up one side. This will cause outgassing (or something like that) from the object. The reaction would nudge it a little and hopefully enough.

 

But all those ideas are useless when you don't know it exists until less than 36 hours before impact!

How much of an impact on earth would exploding a nuke next to the object have? I am sure the effects of the nuke would be better than the impact of the object. As for the problem of detection.....would it buy us any time to put some type of monitoring station on the moon?

[Airbrush]

...As for the problem of detection.....would it buy us any time to put some type of monitoring station on the moon?

 

That sounds great, the best so far! The moon orbits the Earth once a month, the dark side always faces away from Earth, and the moon's orbit is on the plane of the solar system which is where most NEOs travel. The monitoring station(s) on the dark side of the moon would have a great view of space surrounding Earth, and could do the motion sensor scans of broad swaths of space.

 

Hey NASA, check this out!

[Baub]

That sounds great, the best so far! The moon orbits the Earth once a month, the dark side always faces away from Earth, and the moon's orbit is on the plane of the solar system which is where most NEOs travel. The monitoring station(s) on the dark side of the moon would have a great view of space surrounding Earth, and could do the motion sensor scans of broad swaths of space.

 

Hey NASA, check this out!

How hard is it to launch from the surface of the moon, as compared to earth? I am wondering if we launched defensive mechanisms from the moon rather than earth if we could shorten the time of intercept.

[DrDNA]

But what's the effective range of omnidirectional radar? Not far enough to be useful in this case, surely?

 

I don't know. But I think that it is viable.

 

radar astronomy

 

 

radar astronomy, application of radar to the determination of distances and planetary features within the solar system, such as rotation rates. A short burst of radio waves is transmitted in the direction of the object under study. The object reflects the radio waves back to earth, where they are detected by the same antenna that sent the signal. The time between sending the signal and receiving the “echo” can be precisely measured electronically. Since radio waves travel with the speed of light, the roundtrip distance from the earth to the object and back is then easily computed. This technique differs from radio astronomy in that the celestial object is here merely a passive reflector, rather than the actual source of the emission. The first yield of radar astronomy was a much improved value for the distance from the earth to the moon. Using more powerful transmitters, the distances to Venus and Mercury were also measured, as well as the planets' rotational periods and gross surface properties.

........

Radar observations are also useful for asteroids and comets whose orbits take them relatively near the earth. Much of the surface of Venus has been mapped by unmanned probes using radar altimeters to penetrate the cloud cover.

http://www.answers.com/topic/radar-astronomy

 

Now I think that it should work from ground stations.....making it MUCH cheaper.

We could probably do the whole thing for less than half the cost of one Katrina-like event.

Edited March 5, 2009 by DrDNA

[moth]

That sounds great, the best so far! The moon orbits the Earth once a month, the dark side always faces away from Earth, and the moon's orbit is on the plane of the solar system which is where most NEOs travel. The monitoring station(s) on the dark side of the moon would have a great view of space surrounding Earth, and could do the motion sensor scans of broad swaths of space.

 

Hey NASA, check this out!

 

if you want to go to the moon i'd bet on this guy

 

once on the moon could some kind of capacitance effect be used to detect asteroids entering the danger zone?

could the magnetic field around the sun be used to deflect a charged(by microwave or laser beam from the moon) asteroid?

[Sisyphus]

With radar astronomy, though, you still have to be "looking" right at it, right? So it seems scanning the sky wouldn't be that different from just using a telescope. Once you did find it, though, I guess it would be a better way to get more precise location and trajectory. (Again, assuming it would work on objects that small over distances that great, but that's a relatively minor technical problem, I guess.)

[Baub]

if you want to go to the moon i'd bet on this guy

 

once on the moon could some kind of capacitance effect be used to detect asteroids entering the danger zone?

could the magnetic field around the sun be used to deflect a charged(by microwave or laser beam from the moon) asteroid?

I love the TED lectures. I am sorry to say that I was totally ignorant exploration that deep had occured. Great ideas about a fuel station in space, and the potential of the moon. I like your idea about using the magnetic field of the sun. It seems to me that utilizing existing forces like the sun's magnetic field would be instrumental in keeping cost down. Perhaps some of our local physics experts can shed some light on this?

Edited March 5, 2009 by Baub

[Airbrush]

They already use CCD (charged-coupled device) technology on telescopes in sky survey for asteroids and comets. Is there a way to combine radar astronomy with CCD technology? Then a computer does the watching for small position changes in objects that reflect the radar waves.

 

As Baub suggested, besides detection stations on the dark side of the moon, that would also be a good place to launch rockets with deflection systems. The low gravity and 240,000 miles head start would be a wonderful advantage. But that would work only for immediate threats coming from that general direction. We would also need other rockets in orbit around Earth ready for launch at a moment's notice in the opposite direction.

 

We could not receive signals directly from the dark side of the moon, but there could be satellites in orbit around the moon to pick up signals from the moon station and relay them to Earth.

Edited March 5, 2009 by Airbrush

[Baub]

Since CCD technology is being used in photometry, I don't see why it couln't be integrated into radar. Having a computer monitoring the data would certainly be better than staffing stations. Of course, I think it would be agreat job.

 

I am also wondering if the deflection systems, could be in a state of orbit at various intervals ready to be launched via commands from the monitoring stations. Perhaps, the deflection system, as it remained in orbit, could also serve as a remote sensor? Once something is placed in orbit, isn't it rather simple to maintain that orbit? It would only need to utilize its fuel when it was prompted, by the monitoring station, to move.

[Airbrush]

The best place to keep radar detectors and rockets with deflection systems ready for launch would be in orbit around Earth, outside the orbit of the GPS satellites. If the deflection rockets were nukes, which I believe to be the simplest and most fool-proof deflection method, other countries would complain about USA nukes in orbit.

 

But imagine how much political capital the US would gain by saving the planet Earth from destruction.

[moth]

what about a ring of "tripwire" satellites around the sun between earth and mars to detect near earth trajectories and radio update to some kind of beam weapon to affect the offending objects trajectory.

some kind of beam weapon seems preferable to a rocket because of the travel time of a vehicle compared to a beam weapon. you could shoot a beam right past the sun if necessary to hit an object on the other side of the sun, but a rocket would need to orbit the sun to reach the other side(i think).

Edited March 6, 2009 by moth
spellging

[DrDNA]

But imagine how much political capital the US would gain by saving the planet Earth from destruction.

 

Somehow, I don't think it would make much of a difference to a lot of the world's opinion of the US.

Especially, since after saving the planet, anything that could be used to blow up an asteroid would easily be aimed down.

 

That would be irony wouldn't it?

Humanity's last chance of survival doomed because of saber rattling and nonproliferation agreements...........