Discarding Explored Sectors: If you do not want to place an Explored Sector, discard it by placing it in a faceup Discard Pile near the corresponding Sector stack: (I), (II), or (III).
Discarding an Explored Sector ends your Explore Activation. Once all of your remaining Explore Activations are completed, the Action Phase continues with play progressing to the next player.
If any Sector stack is empty, shuffle the corresponding Discard Pile and place it facedown in a new Sector stack. If at any time the Sector stack and corresponding Discard Pile are empty, the Explore Action for those Zones has no effect.