He'd gotten the information Earth needed for analysis; now it was time to get his surviving people home.
Did the Earth really need 400,000,000 more Chinese people using up it's resources?
One of the reasons we have a space program is because Earth needs space's resources!
Earth may not need Mars yet, but one day it will.
As these processes were very gradual, the Earth needed to be ancient, in order to allow time for the changes.
So what you are saying is that Earth will no longer need the belt?
The Earth then needs to rotate a little more to make it line up again.
Earth needed five years at the minimum and ten years would be still better.
The Earth is severely wounded, and needs a lot of time to heal.
Earth needs all the information it can get With nine years' time delay?