From what I've heard, it's the only thing in this universe she hasn't explored

When a cosmic threat crash-lands on Earth, it’s up to the Femaliens to stop it! In her quest for galactic domination, Commander Tharis will stop at nothing to bring home the ultimate prize: the planet Earth. The only thing that stands in her way is Alterian Collector Maxy Prime, who has taken up residence on the primitive planet on a fact-finding mission, befriending a few of the locals in the process. Settling into a new life on Earth, Maxy isn’t going to give her up home that easily, and when these two beauties from beyond the stars clash, they’ll leave a scorching supernova in their cosmic dust.