The far side....
A mission to the far side of the moon and the installation of radio astronomy equipment, would be a massive boost to radio astronomy, shielded from all that pesky noise coming from all those earthlings and their RFI/QRM.
That is only going to get worse, as more badly designed consumer electronic devices come to market.
That alone would make a valid reason for going to the moon and give mankind a new improved eye on the universe!!