As an explorer I noticed that many of my fellow players don't bother to completely scan systems full of icy bodies, let alone map them.
Solution: News article about alien structures of unknown origin found on icy bodies. Add a 1/100 chance to each icy body to contain such structures, but the only way to find out is by mapping the planet. Reward of twice the amount of a terraformable HMC world (plus bragging rights).
That's all. No further game tweaks or in-game explanation necessary. Also doesn't require planetary sites or landing on those planets for now, essentially none of the complicated stuff. You may decide to build on this story at a later time, our you don't. The thing that matters is that you created an incentive for explorers to scan an map icy bodies througout the galaxy.
Solution: News article about alien structures of unknown origin found on icy bodies. Add a 1/100 chance to each icy body to contain such structures, but the only way to find out is by mapping the planet. Reward of twice the amount of a terraformable HMC world (plus bragging rights).
That's all. No further game tweaks or in-game explanation necessary. Also doesn't require planetary sites or landing on those planets for now, essentially none of the complicated stuff. You may decide to build on this story at a later time, our you don't. The thing that matters is that you created an incentive for explorers to scan an map icy bodies througout the galaxy.