"Adriatic" wrote in message
...

Why not we suppose that we can replace Mars with Europa and Europa with
Mars.

The mass of Mars is about 6e23 Kg
the deltaV (mars-jupiter) is about 10 km/sec

Thus the energy needed to move Mars to Jupiter is around 3e31 joules. If
this is done over 100 years the average power required is around 2e22 watts.
If the current energy generation capability of the Earth is 1e13 watts (this
is the bit I'm not sure of), and economic and power growth is constant and
eternal at 4% per year (the philosophy of capitalism and the cancer cell),
then by the year 2667 the human race may be willing to spend 1% of it's
energy resources moving planets.

Comment?