Cheaper Ways to make both Venus and Mars more Habitable

Carl Sagan says in Cosmos that all that water we see evidence for in the ancient stream channels of Mars probably maybe went into the ice caps of Mars and is still there.

 If we look at the evidence about the ancient stream beds they're right beside the craters, which means that liquid water didn't stay long on Mars or it would have eroded those craters rapidly and there will be no craters if liquid water was there over millions or hundreds of thousands of years. Many of the features show rapid erosion but that's about it.

 For this reason I think the real reason that there was liquid water on Mars for only a while was because of lack of gravity, and so if by a plan like Elon Musk's plan of crashing asteroids into the ice cap of Mars to hope to create more atmosphere and water for Mars atmosphere will only be temporary and fizzle away so the plan won't work to hold water and air on Mars anymore than the ancient labor of those volcanoes. As I discuss in my other post about hoping to crash one of the large satellites of Jupiter into Mars via a magnetic bubble (this would use the power of Jupiter's magnetic field to send the high-speed motion of Callisto off towards Mars) to give Mars an atmosphere and water much cheaper and faster than usual terraforming plans, I think we could conceivably use fusion powered excavation machines to dig down radial tunnels inside of Mars and there use the same fusion machines which are almost in reach now to compress the metals and mass of those tunnels in the center of Mars and give it gravity enough to overcome this problem completely.

 Even so Mars is far away and I think even better than just adding gravity or an atmosphere that's non toxic to Mars might be to find a cheap simple way to move Mars much nearer to the earth.

 To do this I propose that we use a satellite around a planet like Mars to move it inward or perhaps Venus to move it outward to Earth radius orbit.
 
 I think this might be achievable by satellites that have both magnets and solar collectors on them.

This method of moving a planet like Mars may be simple.. magnets on Mars, it's natural iron are used so it attracts the satellite with each orbit. The satellite goes around one loop and collects the solar energy with the magnet turned off, alternating on the next orbit with a magnet turned on.

 While this would only have a small amount of nudging with each orbit, orbit after orbit it would build up, moving Mars near to the Earth orbit enough that we have a much cheaper way to travel to and from Mars.

 Others have proposed methods of moving planets like using asteroids to nudge past and move a planet like NASA has considered in the future one day moving the Earth if the sun was engulfing it in billions of years from now about a foot for 11,000 years with the asteroids gravity per orbit. This would be much much slower then the satellite method because while each boost of the orbiting satellite is small, these are like every 30 minutes and each one will multiply and multiply the force on the planet to move it much faster.

 By using those methods of crashing a large more water-based moon into a planet like Venus we could also remove all its bad atmosphere and replace it with more healthy atmosphere for us at any rate!

 And by moving Venus  and Mars to Earth radius orbit, especially if we give gravity to Mars they won't be so hot or cold, with good non radioactive atmosphere that we can breathe with enough water, and so on. As I say elsewhere we can even give them the right amount of daytime 24 hours by setting the impacters to counter this problem which can cause really bad jet lag as the operators of the rover on Mars found. By the end of the mission they were exhausted.