Let's face it: It's only a matter of time until Mars comes after us. We've got lots of water. It doesn't. We've got life. It doesn't. All this might have been okay, but then we alerted Mars to our presence with our various satellites and rovers, and now it's just a matter of time. Here are some ways we might destroy the red menace before it comes after us.
One of the problems with destroying Mars is it's pretty big and pretty close. Granted, it's only about ten percent of earth's mass, but that's a big rock to be only 35 million miles away from us. The last time something the size of Mars hit us, we got the moon. The moon's pretty and all, and it forms the tides, but the earth is built up, covered in life, and we really can't spare another moon. So whatever destroys Mars has to neatly sweep the planet away. How should it be done?
Pulling Mars Into the Sun
This would require a whole other planet - though not necessarily one as big as Mars - and it would take a few steps, but it can be done. In fact, it has been done plenty of times, resulting in some strange planetary configurations. Planets the size of Jupiter orbit the opposite direction of the rest of their solar systems, and their rotations are flipped. They are the lucky survivors of plunges towards the sun. Planets are always falling towards the sun. They are also always shooting away from the sun in a tangential line. They move forward, the sun's gravity pulls them back in, and the result is a stable orbit.
But when two planets get too close to each other as they orbit, their gravity interacts. If one lags behind the other in orbit, the trailing planet's gravity will pull the leading planet backwards, slowing it down. That slowing will cause it to fall inward towards the sun. The inward fall will pull the other planet along, and ideally, they'd both plunge into the sun and be destroyed. This leaves no pieces of Mars to hit the earth, and with luck we might take out Venus or Mercury along with it. Three birds, one stone. Sadly, it would be a very big stone, and we don't have the resources for that right now. Also, part of the time, we are between Mars and the sun. Any miscalculations have us dragged into the sun along with Mars.
Knocking Mars Away
Destroying Mars by knocking it away is tougher than most people think. The Moon is about 1.2 percent of the mass of the earth, and its estimated that up to 80 percent of its mass is that of the asteroid that hit the earth and originally caused the moon to form. Even that impact didn't have too much of an effect on our orbit. To knock Mars away or smash it to pieces we'd have to hit it with something its size or bigger, directly from above or below, and we'd have to make sure that the object we hit it with would keep going along with Mars.
And it's not just the physical pieces of both that we'd have to deal with. Anything that knocked Mars out of the way, even assuming the planet held together and didn't shed world-destroying shards all over the place, would release a massive amount of heat energy. As a comparison, it has been calculated that if an asteroid were to hit the earth hard enough to stop its rotation - not knock it off its orbit - it would release about ten to the twenty-fourth ergs of energy in just a few seconds. That's not much compared to the sun's output of ten to the thirty-three ergs per second, but it would be enough to melt the entire planet. Something that knocks Mars out of orbit would give out a massive amount of energy, heat it into a misshapen lump, and leaves potentially hazardous, steaming-hot pieces behind for the earth to plow into.
Create an Anti-Mars
Perhaps the best solution for destroying Mars would be antimatter. The biggest problem in any of these methods has been the fact that Mars simply won't disappear - it will leave matter zooming around behind. The risks of this can be minimized with careful calculations, but eliminating Mars with antimatter would burn it up completely. Antimatter is like regular matter, but with reversed charges. Protons are negative and electrons are positive. When antimatter and regular matter meet, they annihilate each other, giving off energy in the process. This is why scientists, to maintain antimatter, have to keep it in a vacuum, surrounded by special magnetic walls that keep it from running into anything.
The best place to keep from running into anything is the giant vacuum of space. In order to get rid of the Mars Menace, all we have to do is build an orbiting platform where we can create Anti-Mars. Build an entire anti-planet, send it off towards Mars, preferably when Mars' 687-day orbit takes it farthest from the earth, and run them into each other. Next thing we know, there'll be a nice clear spot in the sky without any kind of unpleasant debris left over.
At last we'll be safe.
Mars Images: NASA