Don't quite know what to say...
"Good luck!" comes to mind, though, after the intial shock.
To say you'll be missed is not only obvious but ridiculously understated. Long before you became a moderator - long before there was a Habitable Zone, going all the way back to the unlamented Looney Bin - you've been the backbone of this group. More than anyone else, you've assumed the responsibility for keeping a steady stream of news coming in for the rest of us to pick apart, argue over or laugh at.
Be well, friend - and keep in touch.
Fox