But Mars rotates already. It's day is similar to Earths. A Martian day is 24.7 hrs. I takes Venus 2802 hrs. to complete a rotation. Mars diameter is 95% that of Earths and 80% of Earth's mass. I haven't put the figures to it yet but you take this into account and Mars is very similar to Earth other that atmosphere. A change in atmosphere would change other small differences. For the biggest bang for the buck, I'll put my money on Mars.

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odin1

People will forgive you for anything -but being right !
odin1