What exactly is the definition of a planet? I've heard lots of talk on if Pluto is or isn't a planet but I don't really know what constitutes a planet?
Sedna eh? Andes backwards, or undies if you prefer.
I don't know if it should be classified as a planet, it's even smaller than Pluto, and both Pluto and Sedna are smaller than our moon, which is 3476km in diameter. And to put things further in perspective the continent of Africa is larger than the circumference of the moon.
Has anybody checked to see if we have any whales left?
LMAO
"Oh Mikey do you think I even know what the hell they are talking about half the time? I dont know whether they are talking about how hard it is to be adopted or how their father never shows them love. All I do man, is I wrinkle my eyebrows, stare at their lips and somehow I turn out to be some big sweetie." - Trent Walker (Swingers - 1996)
All the sub-categories for planet classes are confusing but isn’t the main difference between a ‘star’ which could be a planet nursery or planet eater as follows. “Star” defined as a self luminous object composed of gas with fusion occurring at its core. ‘Planet’ (of any size) larger than an asteroid but smaller than a star. Composed of a fusion-less solid core though not necessarily solidly formed to the planets exterior surface which may be composed of gaseous layers and capable of reflecting light yet not self-luminous? Planets always in orbit to stars?
The definition of 'planet' has been getting murky for a few years now since we now can see further out into the area beyond Pluto and also resolve the many small bodies that are bigger than asteroids and have independent orbits. Once we look at the icy bodies in the outer reaches of the system you'll find probably millions of iceballs like Sedna orbiting the sun. The more we learn, the less our old labels apply. At some point the arbiters of astronomical naming conventions will have to set defining lines, but they don't exist just yet.
But that's just me. 
