Really? Not to bust your chops or anything, but what proof can you offer on your expertise in civilizations from other star systems? There are LOTS of ways to categorize the things orbiting our star, and an alien might use any number of them to make the determination. An alien society might not even understand the distinctions we draw or why we draw them. They might not name planets, dwarf planets, or even stars. On the other hand, they might name everything down to the bolt that got lost on the last space walk. We just don't know.

Lets see....how could you arbitrarily define "Planets" versus "Rocks orbiting stars"

Must have an atmosphere (with some specific minimum pressure/volume/etc so that 4 molecules of O2 doesn't qualify)

Origin of life (you could really conserve names with that one)

Currently supporting life (you want us to bother calling that crappy ball of dirt ANYTHING, you get your lazy butts off that rock and colonize it)

Specific minimum (or maximum?) mass and/or size

Specific minimum (or maximum?) densisty (Pluto is back to planet status, but Saturn gets the boot?)

Must have moons (again with some specification as to what makes a moon)

Minimum and/or maximum distance from the parent star

Must orbit couter-clockwise when viewed from their star

Must produce a minimum number of twinkies and moon pies

Or who knows what....

I mean really, other than confusing school children, what purpose does this serve? Pluto is still Pluto. It gets to keep its name, its orbit, and its moons. Nothing changed about the object. Its just a big rock with a name, like several other big rocks in the system.