How to Keep Asteroids Away: Tie Them Up



 It may not look like much, but that drawing could save a life someday — or 7 billion.

 David French, a doctoral candidate in aerospace engineering at North Carolina State University is proposing a new tool for the anti-asteroid arsenal.

French said his PhD advisor Andre Mazzoleni, an associate professor of mechanical and aerospace engineering at the university, were not beholden to grant funds and “we just decided to go off on a direction that’s interesting and exciting.”

Mazzoleni has worked with tethers in other applications, and the two have now come up with a way to effectively divert asteroids and other threatening objects from impacting Earth by attaching a long tether and ballast to the incoming object.

By attaching the ballast, French explains, “you change the object’s center of mass, effectively changing the object’s orbit and allowing it to pass by the Earth, rather than impacting it.”

NASA’s Near Earth Object Program has identified more than 1,000 “potentially hazardous asteroids” and they are finding more all the time. “While none of these objects is currently projected to hit Earth in the near future, slight changes in the orbits of these bodies, which could be caused by the gravitational pull of other objects, push from the solar wind, or some other effect could cause an intersection,” French explains.

He said it’s hard to imagine the scale of both the problem and the potential solutions — but he points out that some asteroid impacts on Earth have been catastrophic. 

“About 65 million years ago, a very large asteroid is thought to have hit the Earth in the southern Gulf of Mexico, wiping out the dinosaurs, and, in 1907, a very small airburst of a comet over Siberia flattened a forest over an area equal in size to New York City,” he said. “The scale of our solution is similarly hard to imagine.”

The idea is to use a tether somewhere in length between 1,000 kilometers (621 miles; roughly the distance from Raleigh to Miami) to 100,000 kilometers (62,137 miles; you could wrap this around the Earth two and a half times).

Other ideas that have emerged sound no less extreme, French notes. Those include painting the asteroids in order to alter how light may influence their orbit, a plan that would guide a second asteroid into the threatening one, and nuclear weapons.

“They probably all have their merits and drawbacks,” he said. “Nuclear weapons are already accessible; we’ve already made them. I can look at my own idea and say it’s long duration and very trackable.”

A tether effort could last in the ballpark of 20 to 50 years, he said, depending on the size and shape of the asteroid and its orbit, and the size of ballast.

French acknowledges there are “technical barriers that have to be surpassed.”

“First, you would have to mitigate the rotation of the asteroid,” he said, adding that the crescent-shaped piece connecting the poles on a globe might make a good conceptual model for a tether anchor, because it would allow for the asteroid’s rotation.

Another problem is the composition,” he added. “Some asteroids are just rubble piles.”

French said his idea was never to have all the kinks worked out on his model before presenting it; he just hoped to add another option to the asteroid-preparedness table.

“We’re opening up the concept, and we invite the broader scientific community to help us solve the issues,” he said.

Source: An NC State press release, via Eurekalert, and an interview with David French.

39 Replies to “How to Keep Asteroids Away: Tie Them Up”

  1. All good if we have the time to do such a thing. How much warning for this would you need. Why not just spear the thing with a long pole. It may have somewhat the same effect.

    i don’t know. This seems kinda out there.

    Maybe a big baseball glove to catch the pesky thing. Oops! did I say that.

    Remember the last NEO. We didn’t have time to do squat. It was small mind you and went undetected mostly becasue of this but …

    What if the tether breaks and casues another comet that could come back and haunt us. Then we need a tether for the tether…

    Needs more work back to the drawing board.

  2. Why not nuke that recent North Korean “satellite”? Oh, wait, we’d need a torpedo for that 🙂

  3. Jon. Best idea ever. Then the governments can also have a place to test nukes…. and they can call it science, investing in companies like SpaceX to get that stuff up there pushing technology and innovation to new heights!
    I hope somebody in government is reading this. Elon musk may want to think about pushing the idea…..

  4. Nuking an asteroid isn’t a good idea no matter how much or little time we have to deal with it, for reasons given above. We need as many observers as possible looking for potential troublemakers out there, so we can deal with them in some effective way while there’s still plenty of time. Just no nukes — we do *not* need a hundred bazillion godzillion radioactive chunks of asteroid or comet aimed right at us, which is what a nuclear “solution” to the problem could do.

  5. Great idea to save us on OUR world but the ballast-tethered asteroid’s new trajectory could doom the living things on another undiscovered world which would been spared if it wasn’t for us pesky Earthlings always acting only in OUR best interests.

  6. I could do it easy! Zap it with a big electric current and that current will change the gravitational constant and it will just fly off never to return. LOL

    Serious now.
    Ok, it is very interesting to change the asteroids mass by just puttng some weights on it and thus it’s orbit.

  7. Have no fear, the Electric Universe is here.
    Use Plama Physics to blast them out of our way.

  8. We should feel bad bout these EU jokes, but then again these are funny people hard not to lauch about. 🙂

  9. Not forgetting the gravitational attraction method to just steer the asteroid to pass safely by – as opposed to blowing it into a billion deadly radio active meteorites

  10. “Great idea to save us on OUR world but the ballast-tethered asteroid’s new trajectory could doom the living things on another undiscovered world which would been spared if it wasn’t for us pesky Earthlings always acting only in OUR best interests.”

    I think you have a serious misconception of the concept of scale – any undiscovered worlds are so far away that the chances of the asteroid ever even reaching their solar system are what mathematicians call “a nonzero event” aka a practical impossibility.

    Even if we intentionally aimed the blast to guide the asteroid towards another star the odds of it coming anywhere near a planet are almost nonexistent.

  11. I agree with Tyler Durden, this balast-thethered would probably not even leave our solar orbit, just a bit of additional change that it misses earth and flies a few million km further.

  12. How do you get a 100,000 kilometer long rope into space? Can you see them tieing one end to a small asteroid, and the other to the big, nasty asteroid and then when the line tightens, p-twannngggg! and the little earthy tether breaks.
    Please don’t try this at home.

  13. Obvious problem with the plan:

    Ever tethered a moving mountain?

    You need to match the speed and direction of the ballast rock perfectly to the target rock … or else you need an infinately strong tether that won’t snap when the slack is taken up.

  14. I saw Superman deal wth an Earth-bound asteroid: he just gave it a shove, whereupon it continued on its merry way, never harming Earth, the USA or us. GO, Superman!

  15. Hmm. Is this the solution:

    I saw Superman deal wth an Earth-bound asteroid: he just gave it a shove, whereupon it continued on its merry way, never harming Earth, the USA or us. GO, Superman!

  16. why does everyone thinking of blowing up when you talk about use Nuclear weapons?? why can we just explode one close enough to the body not to blow up but the shock impacted will give it the push it needs???

  17. What if the asteroide has a chaotic rotation along multiple axis? The crescent part wouldn’t work then. Aa all the schemes proposing something fixed to the asteroids such ass painting…

    I read somwhere of a proposal aiming a laser at the asteroide. The vaporizing material would create a jet powerfull enough, given enough time, to nudge it out of the way.
    As the laser is always pointed from the same point the direction of the jet would also be most of the time the same, the only influence of the rotation being the changing geography and thus slight changes in the direction of the jet…

    Deflection by a nuke wont work unless you use the nuke at the surface or very near it of the asteroid. Remember space is a vacuum, so you wont have much of a blast.

  18. I’m thinking if we get (un)lucky enough to have a sizable asteroid headed toward earth we should try to capture it in an orbit and mine it. At any rate, early detection is key.

  19. Silver Thread Says:
    “I’m thinking if we get (un)lucky enough to have a sizable asteroid headed toward earth we should try to capture it in an orbit and mine it.”

    You’d need to mount thrusters on it, lots of them, like many dozens of very large rockets… and propellant, probably several times the mass of the asteroid itself.

    The giant base ball glove looks like a better idea… 😉

  20. Firstly, I wonder how to fix a long thin tether to a rotating asteroid that travels along its orbit at a speed of e. g. 35 km/s.

    Secondly, consider that an asteroid of a 100 m diameter has a mass of millions of tons, while the maximum mass we can bring into space at a speed of 11 km/s is a few tons.
    Trying to change the orbit of an asteroid by the force of such a low mass is as effective as trying to change the path of an airplane by colliding it with a butterfly.

    Thirdly, nukes are powerful with regards to our standards. The kinetic energy of a small million tons asteroid travelling at 35 km/s is 65 times greater than the energy released by a megaton nuke explosion. Therefore, a nuke is not as effective on an asteroid as is impressive for ourselves.

    Such, we can only hope that asteroids will keep on missing us out as they usually do.



  21. Great idea to save the earth, but I don’t think to blust the asteroid is a good Idea for those who proposed it.

    We need to think about both effects positive and negative, and stating nuclear means worse to begin with and also because of combinations of gases that will be caused in outer space in which we are not sure what effects it will have on earth.

  22. Vaporize electrostatically charged tarballs out in front of the comet to coat the surface black?

  23. Silver thread’s idea of capturing an asteroid is the most useful item I have seen here, and it isn’t necessarily as hard as it seems. We certainluy have the capacity to throw a nuclear engine at an assteroid of the right size and composition. It can then use the heat it produces to vaporize and use as thrust material from the asteroid, continuously 24×7. In the process, if the asteroid is rotating at too difficult a rate, we can put multiple nuclear engines on it that together can control the rotation rate while pushing the asteroid where we want it. Such nuclear engines were designed back in the 60’s and 70’s and a few were built and tested in fairly long runs. These were also well within the boost capacity of something like the Jupiter Launch System, or the awful Ares V. If people are worried about safety, and they should be, fuel and engines can be launched separately, with the fuel encased so that any suborbital accident could not create a radiation event. Certainly, with materials created in the last 50 years, something much better can be built along with the technology to allow it to use asteroid material to throw for thrust. I would say that the simplest method would be to power lasers to vaporize material to be thrown by magnetic rings also powered by the nuke.

    For any asteroid coming at us soon or as a rubble pile or in the form of a comet, I don’t see many options other than nuclear, and you have to have some imagination. You don’t blow it up, you push it directionally. A single nuke will not probably do the job, but a properly deployed network will. You set up the array of weapons so that their blasts overlap, producing a pressure wave that will move anything at it’s focus as a whole, and in the direction wanted. There may be some spreading of debris from the focal point, especially with a rubble pile, but the impetus of the group will be out of the orbital path towards the Earth, and I cannot imagine anything else that can do the job in the short term. If you have time, almost any method that you can manage will do. The soot method sounds easiest, as changing the albedo will certainly change the light impulse and move either solid or rubble pile. Unfortunately, soot won’t change the albedo of many asteroids or especially comets by very much, so other methods may be necessary. It would take a lot of white paint to change the albedo of a comet. I’d say that we might need to go back to the blast method for most comets.

  24. For the “rubble pile” sort of asteroid, I’m thinking of a sustained laser hit, or a series of them. A solar powered laser, based on the moon, perhaps.
    Remember in Larry Niven’s Ringworld, he used enormous magnetic fields to direct the solar wind and target it wherever. Would a large magnetic installation in solar orbit be able to direct a portion of the solar wind AND maintain an orbit at the same time?

  25. Use the CERN machine and create a black hole near the asteroid, it will suck the Asteroid in, no asteroid, no problem

  26. I know I’m probably too late to ask this bbbbbut,
    what will keep the tumbling rock from tangling or even winding in the tether, nodes and ballast?

  27. I know this may be a bit futuristic (or maybe not too) bbbbut, I envision setting down a lander at a precise location such that that location would always align with a Trajectory Vector. Now at every TV alignment, an appropriate sized Pulsed Nuclear Rocket would fire and with enough pulse firings + enough time (kinda essential) would gradually nudge it out of harms way.
    I know the lander would have to be secured to the surface to counter PNR recoil and a lot of puter algorithms would be required to keep it on T but hey, we can always call on Bruce and his crew.

  28. I forgot to mention that the PNR would be gimble mounted for computer guided vector correcting.

  29. My original wording “always aligned” meant aligned at a precise moment when during tumble it would be aligned on a Trajectory Vector to nudge it out of harms way and the PNR would fire.

  30. Hmmm . . . let’s see! Something the size of Mt. Everest trapped inside the Sun’s ‘gravity well’ traveling maybe 100 kilometers/sec on a collision course with mother Earth will most likely be impossible to deflect or destroy. The amount of energy, delivery and precision staggering. A little like a canary deflecting a run-away train.

  31. Everett doesn’t think things through.

    Putting a engine or a rocket on an asteroid isn’t as easy as you think. You would need quite a few, they would need to be coordinated… and if they weren’t placed correctly, the asteroid would just spin.

    Don’t even get me started on trying to blow it up… I mean seriously… it isn’t like this is the first time that was ever brought up.

  32. using a nuke on a asteroid would be pointless and even more harmfull… The only thing nuking a asteroid would do is create thousands of samller asteriods…

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