Level 4 anomaly: Mismatched
The planet's composition does not match our projections for celestial bodies in the [Solar System].
Success: Captive Rogue
[Science Ship] confirms that the moon [Moon name] is, indeed, not of this system.
It looks like some force had propelled this moon across the galaxy from its home system and after aeons of travelling as a rogue planet, it was finally captured by the gravity of [Gas Giant].
Trigger: Is barren or frozen moon of a gas giant
Level 4 anomaly: Mismatched The planet's composition does not match our projections for celestial bodies in the [Solar System].
Success: Captive Rogue [Science Ship] confirms that the moon [Moon name] is, indeed, not of this system.
It looks like some force had propelled this moon across the galaxy from its home system and after aeons of travelling as a rogue planet, it was finally captured by the gravity of [Gas Giant].