A Shot In The Dark
There a a few ideas around concerning how to deal with near earth objects in space who's trajectory sets them on a collision course with earth; the kind which could cause catastrophic destruction to the planet's surface, and possibly spell the and for life on earth... such as using a mirror in space to reflect the sun's strong rays to focus a beam on one side, causing it to evaporate rapidly from the point of focus and emitting a jet of steam which will propel the object away in the desired direction.
Indeed, I have posted one such method for breaking up a comet into atmosphere dissolving portions should any such approach the earth (Idea: Spinning Comets
. If anyone has read it!).
But even my idea cannot deal with the hard lumps of rock which are asteroids using the method I have described, as they have a solid consistency, and therefore a greater structural integrity than the icy comets.
And so to deal with these I propose a new potential solution:Catch Asteroids in nets, and float them serenely to the earth.
The usual solution people will put forward if asked to think of a way to deal with such extraterrestrial material plummeting toward us is to launch a nuclear weapon at it and destroy it, but there are many reasons why this is increasingly seen to be unrealistic... among them, that if an asteroid presents a significant threat to the earth, it is either because it is too large to be destroyed by such means, though it may be moving slower, or that it is small, but moving incredibly fast- thousands of miles per hour- and if a rocket is fired directly at it the relative speed between the rocket and the asteroid is greater still, and is incredibly hard to target, with a slight miscalculation leaving the rocket flying past the target, and if the weapon is remotely detonated in such a circumstance, the asteroid, travelling at such immense velocity could be a thousand miles or more past the rocket in the time it takes to realise it, and push the button... leading to the situation, which is the same reason the weapon cannot be detonated if made to approach from behind; firstly, that even if it is successful, it would fragment the asteroid, and the explosion would propel the pieces at even higher velocity toward us, or secondly, it fails, and pushes the whole thing faster toward us.
Either way, not good.
And all of this is itself dependent on whether you can safely launch a nuclear weapon entirely out of our atmosphere without incident itself of catastrophic proportions (a nuclear detonation above the ground is thought to be more devastating than a ground impact, as the earth itself does not absorb any of the released energy.Hard Rock Sachet
My method is this:
A rocket is launched (or as many as you feel is best to ensure you deal with it) which has a pay load of a giant circular net, folded into a long, narrow, tapering cone to fit inside the length of the cylindrical rocket. This net has a series of small thrust rockets attached at equally spaced intervals around the net's circumference... each of which can adjust it's thrust vector relative to the flat plane of this unfurled net around the rim.
The rocket travels out in a giant looping course in space, and as it passes the apex of this loop, and begins to return, it does so along a trajectory designed to intercept the approaching asteroid and roughly match it's velocity, although slightly faster, in order to get ahead of it, and yet allow time enough, once it is ahead of it, to make adjustments to get the rocket exactly in the line of the asteroid's projected path.
Once positioned in the asteroid's path, the rocket opens (sliding, semi cylindrical
door with a seam along the rocket length perhaps), the folded, conical net with the thrust rockets around the rim (in the net's conical configuration stage, the rockets are positioned close together, gathered up, if you will) is released with the rocket then moving away, leaving the net in the asteroid's path, where the rocket was.
This net then opens to it's full, flat, circular configuration by means of the thrusters giving minute positioning bursts, presenting a target like surface for the asteroid to fly at. By matching the speed if the asteroid it won't just rip through the net out the other side, but instead, as the net is gently slowed, the asteroid simply pushes into the centre of the net, which then closes back up around the asteroid... like if you throw a ball into a floating carrier bag, the bag closes up around the ball because of the energy of the ball pushing in the centre of the bag, leaving the outermost extremities of the bag trailing behind, and offering a wind resistance to slow the whole thing down, so the closed net pulls the outermost edge- the circumference of the net- together, and so the thrusters come together like a bag closed around the asteroid.
Having effectively caught the asteroid, all that remains is to slow it's velocity to a degree that is harmless to the earth, or at least sufficient enough to greatly reduce the damage it can do.
This is done by firing the thrusters in a direction contrary to the asteroid's path, and acting as a brake... over sufficient distance this can be a significant reduction, perhaps enough that the asteroid (and net) can fully burn up in the atmosphere by the time it gets here, or, if it does come into our atmosphere, where there is wind to resist, and slow it, a parachute can be deployed to slow it further, and gently ease it down until it lands with just a small bump on the earth, or plop in the ocean.
This basic principle is the same as that of a baseball player's catcher's mitt, where he runs the same direction as the ball in flight, and uses a “soft hands” technique to allow the ball to pull the mitt a little and expend it's energy, while the mitt closes around the ball.The rocket, and possibly the net, are re-usable, and the asteroid potentially in tact for scientific study, gift wrapped... in a bag.