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Old 06-12-2016, 08:40 PM
DagNation DagNation is offline
Join Date: Jan 2009
Location: San Diego
Posts: 201
Originally Posted by robby View Post
Another related option that has been studied is the possibility of using a large asteroid in a gravity assist maneuver to transfer orbital energy from the outer planets to Earth in order to expand Earth's orbit.

Estimates are that it would take thousands of gravity assists to make a difference.
This is the easiest answer - most of the energy comes from the large outer planets, a tiny fraction comes from maneuvering thrusters that align the trajectories and make it work right.

Assuming the goal is to gently raise the orbit of earth to counterbalance the rising output of an aging sun, an increase of average orbital radius of a million miles over a hundred or thousand years is going to be enough to do the job, and do it very gently in terms of tidal affects on the surface.

I think a major challenge would be to do it without messing up the moon's orbit.

As long at we have massive rocket-powered asteroids transferring all that orbital energy around, it would be difficult to not effect the other planets, so might as well make use of it all. It would be fun to grab Mercury, Venus, and Mars, and put them in orbits at earth's L-points.

It would be nice to move the other rocky planets because it would be a lot easier to terraform them if they were in our Goldilocks orbit and had the same solar input.