Okay, I'm back. That was a nightmare of an assignment, now I hope I can sleep enough such that I don't go insane and/or die.
So, in the early days of this blog, I showed you plans to terraform Venus and Mars, both plans being thousand-year, trillion dollar, logistical nightmares that would provide multi-trillion dollar benefits. And of course, that won't get financing because no one organization is sure that it will live that long. (I can describe the UK as being that old, if I really stretch the definition of what "the UK" is.)
But let's say you handed me all the money on the earth, and demanded that I produce a terraformed planet in 100 years. This much, I think I can handle. With the insanest plan, ever.
Using some very large mass driver (to be invented by someone at NASA, someone more insane than me), we haul Venus from its current orbit, and into the L4 Lagrange point. If this causes too much gravitational disturbance, we can replace it with its weight in similarly mass-driven rocks from deeper in the solar system. The Kupiter belt if need be.
Now we go to Mars, and ram its two moons into its surface. Then we mass-drive it over to L4. That's right, we ram them together. Preferably at an angle other than 90 degrees, because we need to spin Venus up.
The two will violently collide, providing quite the light show here on earth, slagging both of their materials molten. Part of the two will spin off into a small moon, and the other one will spin quite fast, having a ten hour day. Toss a few ice meteors at this every year, both to provide oceans and to keep the cooling time down to a mere 100 years.
At this point, the planet is like early Earth, but don't move there yet. No oxygen. You'd die. But when liquid water is apparent on the surface, it's time to bring over many plants. Any humans doing this would have to wear diving suits, because the pressure would be great, but the air would choke you dead. When the seas are full of seaweed and the ground is full of trees, then we watch. Within 50 years, it should be human-breathable.
The good news is that the planet would now support human life, but the bad news is that this would be a baby planet, with no fossil fuels. If you want coal or oil, you'll have to bring it over from Earth, at great expense. A better idea would be to fill it with wildlife and hippies. Zoo-planet, maaaaan. Also, Theodore Kazinski. He'd love the wilderness, and maybe he could manage to not get eaten.
If this plan proves wonderful, we can repeat it with Jupiter's moons, Saturn's moons, Uranus's moons, and some Kupiter belt objects, all tossed into L5 and exploded together.