Artifacts can be great and all, but the cost to use what is essentially a gamble button is very high unless you are Advent with the cost reduction tech and/or the Progentor colonize bonus. The minor discoveries (ie Penal Colony and such) are clearly meant to be more useful when a planet is first colonized, but nobody can afford to do this early game. Right now this option is basically a late late game thing for TEC and Visari. Advent are a bit better off because of said tech, but even then they still need to research it before they can start using Explore Planet efficiently. Some suggestions:
-Add more minor discoveries, and increase the chance of getting one. More benefits and less risk make trying for one more appealing early on.
-Are there going to be more artificats in Rebellion? Also, the balance between them is iffy. 15% weapon damage to everything? Yes please. Reduced travel time between stars? When is this going to matter?
-Failing that, Explore Planet desperate needs a cost decrease. TEC and Visari simply can't dream of wasting money on this early on.
Just some thoughts on what should be cool option, but it pretty much ignored until end game right now.