We already have this on legion members, but I would like to see this on planets and the battle tab as well. It would tag all of them that has been off for at least 3 weeks. That way people don't have to check up to see if a planet is owned by someone who is not playing anymore.

+1 I love this idea, it's a pain to have to go through my scanned planets and try to remember what level they were a couple days before.

Yeah, maybe a little longer than 3 weeks, maybe at least a month, but yeah, at some point they should.