I had the idea that it could be used to terraform mars... but asteroids are very different from dominos, so I just want to know if it's even plausible.

Anyways here is my terraforming idea: First get a small asteroid and fling it into a slightly larger one (expending a small amount of investment fuel), then that one on it's altered course hits an even bigger one, and so on until a very large rock smashes into mars and stirs up the ice cap spewing volatile green house gases into the atmosphere, which then warms up. Viola! ...right? Well I just looked up a video about the domino effect: http://www.youtube.com/watch?v=5JCm5FY-dEY and realized that it works by converting gravitational potential energy. Each block is capable of knocking over a block 1.5 times bigger than itself because the energy needed to get it rotating out of its equilibrium is less than the energy converted from gpe into rotational energy. In other words, by the time it smacks into the neighbor it's got a lot more energy than went into knocking it over. But asteroid collisions certainly is more complex than rotation around an axis etc. and orbits give me headaches...


No, a chain of collisions between asteroids is not plausible.

The effect works in the video because the demonstrator has gone to a lot of trouble to set up the dominoes. He has balanced them on their narrow edge (where they are unstable), aligned them parallel and spaced them out so that the chain reaction goes all the way without a hitch. The blocks have potential energy which is released as kinetic energy when they topple. When it reaches its neighbour, each block has sufficient KE to topple it, despite being smaller. (It would be an interesting exercise to calculate the conditions needed for each domino to topple its much larger neighbour.)

I don't see how you are going to place asteroids in positions of unstable equilibrium. It is not as simple as stacking dominoes on a level floor. Positions of unstable equilibrium - Lagrange Points - do exist for very small bodies in the gravitational field around two large orbiting bodies, such as the Earth and Moon. So it is not impossible, but you would need to get the asteroids into position in orbit around much larger bodies. If the last asteroid is going to crash into Mars and have a "world-changing" effect, the asteroid would have to be parked in orbit around a planet or star much bigger than Mars.

There are three major problems with the collisions between asteroids : (1) Unless the collisions are just enough to "nudge" the larger asteroid out of orbit, the larger asteroid could break up unpredictably. (2) Rotation and irregular shapes of asteroids make the outcome of collisions difficult to predict. (3) As a result of the large distances between asteroids, any small deviation from one collision could miss the next asteroid and stop the chain reaction from being completed.

It will require far more ingenuity and effort to set up the chain of collisions than to accelerate the largest asteroid to the required speed and point it at Mars.


In my opinion terraforming can't be done by asteroids. In defense of my argument I would like to start with the definition of terraforming. It means forming conditions that would lead to the planet or satellite becoming suitable for life.

Sure, using an asteroid to spew greenhouse gases into the atmosphere would help to maintain a temperature that would sustain life. But! there are plenty of other concerns that make Mars unsuitable for habitation-

1) Cosmic radiation- Mars doesn't have a global magnetic field like earth that could protect life from the cosmic radiation that it encounters. Even the origin of magnetic field of earth is subject to controversy. I don't think an asteroid can solve that problem.

2) The atmospheric pressure of Mars is too low. I'm not sure what causes atmospheric pressure. Is it the rotation speed of the heavenly body in concern? Even then it would be a long shot to think that you could change the rotation speed of Mars with an asteroid.

My suggestion would be to mutate organisms that could survive Mars rather than risking blowing up our dear neighboring planet! :D

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    $\begingroup$ I think you are missing the point of the physics question here, which is the possibility of making a chain of collisions between asteroids. Terraforming doesn't come into this and is off topic (in my opinion). $\endgroup$ – sammy gerbil Oct 6 '16 at 12:33
  • $\begingroup$ i dunno.. I felt it was more related to plausibilty of terraforming. it'll be clear once OP responds :| $\endgroup$ – Sad_lab_rat Oct 6 '16 at 12:46

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