Moving a planet is sheer insanity. Our solar system is like a bunch of plates balanced on a tray held in the air by a nervous waitress racing to a mean customers table. Everything is just so and any shift will throw everything out of balance and cause disaster.

If one wants to create a sizable atmosphere on Mars one first needs to create a magnetosphere capable of preserving and nurturing it. Our planet uses our liquid iron core to do this. In the future, technologies will be developed that permit the generation of such a field, magnifying any existing iron in the core with currents

In effect the cores will be turned into electromagnets - producing artificial electromagnetospheres.

This is far easier than moving the planet, though the technology is still outside 2009's grasp. Reaching the core and electrifying it the primitive way would requires a series of enormous powerplants and improved drilling technologies to send current into the magma. However advanced technologies will arrive which permit the existing field to be completely identified and via induction, using transformers the core will be targeted with electrical energy.

Many worlds (could;-) use this technique to bolster their magnetosphere to varying degrees. An aging world with an aging sun, creates less field interaction. This permits too much radiation in. So turning the magnetosphere into an electromagnetosphere (likely) is a top priority for worlds with fluctuating stars or for those intent of colonizing and terraforming other worlds.

Captains Log, Earthtime 1/19/2054 GMT 5:34 PM

My scientific cruiser IronEye has landed on the asteroid Eros in the crater Casanova. Our mile long ship has endured the voyage without incident. The crew is working feverishly preparing to anchor our craft and set up the enormous solar array. Our companion ship, the Field Queen, paces Eros and awaits our crews arrival in our escape shuttle. The IronEye's solar arrays and generators will be activated by remote signalling once we are all safely aboard the Field Queen. Eros will have an artificial electromagnetosphere and the IronEye will remain as Eros' primary unmanned station. Oxygen and carbon dioxide will be pumped over Eros and instruments will monitor how long it remains. Creating environments that resist solar and deep space bombardment has been the primary goal of manned space exploration since 2021. Back on Earth, this data will be used to eventually augment Earth's own natural magnetosphere.

The ships sensors already are picking up rich deposits of ores and our secondary mission, paid for by private corporations, is to report on the mining prospects of Eros. Gold is in abundance, and nickel is predominant. Rare metals and some unidentified elements are confounding our spectrometers. The mining companies will be very happy and IronEye will serve them well.