I would find interesting to introduce more deceiving tactics in the game, one of these could be some sort of Ship hologram/clone artifact.

Action: released on a planet, act like your ship is guarding this planet (showing respective def/atk stats) with you actually being guarding another planet. Would deter someone from attacking the planet eventually. However if someone attacks the planet, the artifact effect would vanish and the planet would show its real stats.
Effect time: 7 days (like planet traps)

I like this!