Slashdot Mirror
New Horizons Gets Closer to Pluto, But Mystery Spots Now Out of Sight
The L.A. Times reports that the strange spots spotted on the surface of Pluto by the New Horizons mission will be on the wrong side of the planet for the approaching fly-by that the craft will make of the smallest planet (or dwarf planet, depending) of our solar system. (The BBC makes a similar observation.) That doesn't mean that New Horizons' approach is anything short of "a spectacular event."
Pluto as a planet doesn't really make much sense, without including others.
Eris, for example. While currently three times the distance of pluto from the sun, at times (next ~2800AD) it is actually closer than pluto to the sun, as well as more massive.
There is no real inarguable set.
... without including others
Exactly. They should be included, obviously.
The concept of a planet is pretty intuitive - it orbits a star and its big enough that its gravity has pulled it into a sphere. That's what pretty much everyone on Earth outside of the IAU understands a planet to be. The concept that you have to try to pretend that diversity doesn't exist in order to shrink down the list to a number whose names schoolchildren can memorize is a horribly unscientific approach.
We need to accept the universe that nature has created for us. There are terrestrial planets. There are gas giants. Ice giants. Eccentric giants. Hot jupiters. Super-earths. Water worlds. And yes, dwarf planets. They're all planets by pretty much any reasonable definition. In fact, they're a lot more similar to terrestrial planets than gas giants are.
We should be thrilled by the number of worlds in our solar system instead of intimidated by it and trying to write them out by a ridiculous definition that leads to absurd consequences. And uses nomenclature ("dwarf") that even the IAU itself doesn't use elsewhere (do they plan to declare "dwarf stars" to not be stars?). An "adjective-noun" is also a member of the group "noun" in any realistic nomenclature.
Extrasolar planets aren't planets according to the IAU either. You could have an exact replica of Earth orbiting an exact replica of the sun with an exact replica of Earth's "neighborhood" and it'd still not be called a planet. And even if they didn't arbitrary exclude them, we'd have no way to be able to determine if any of them had "cleared their neighborhood" without sending a probe there - aka, effectively impossible at this point in time. Not that "cleared the neighborhood" makes any sense, there's lots of objects in Earth's neighborhood, and new ones keep entering our neighborhood. And many of the planets don't appear to have formed in their current neighborhood anyway. Plus, Neptune has freaking Pluto in its neighborhood. And since when does what something "is" have anything to do with where it happens to be currently located? Would it make any sense for a cow be declared a "dwarf cow" and not really a cow if it was exactly the same but in a location that had several cowlike animal species near it? Would it make sense to make a definition of a "dwarf river", with the only rationale being to limit the total number of rivers in the world to 8?
I can just imagine an IAU-inspired Star Trek:
The human body can be drained of blood in 8.6 seconds given adequate vacuuming systems.