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."

Comments

Re:Meanwhile....

[queazocotal]

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.

Re:A rose by any other name

[Rei]

Why do you feel that you have to memorize them all? Do you feel compelled to memorize all of Earth's rivers or all of the named stars in our galaxy? The concept that "what I can remember all the names of" is grounds for a scientific classification is an absurdity.

And New Horizons' Alan Stern recommends - and I agree - that indeed moons that would otherwise meet the definition of being a planet except that they are moons of a planet should be seen as planetary moons. So our solar system could be said have several "planetary moons" and "dwarf planetary moons" - Earth's, the Galilean moons, Titan, Triton, maybe others. "Planet" being the general category for non-stars in hydrostatic equilibrium, "planetary" being the adjective form, "moon" being a body in orbit around something that's not a star, "dwarf planet" just being a category of planet, etc. They're all just different categorizations that you can apply where they're needed. Other systems might have other types of planetary moons, even gas giant moons.

Likewise, you should be able to have planetary bodies that aren't in orbit around anything and drift freely through space. We don't have the technology to spot them yet, but I wouldn't be surprised if the galaxy was chock full of them - why shouldn't it be? What an object orbits around doesn't define what it is. So you could have roaming terrestrial planets, roaming gas giants, roaming dwarf planets, and on and on.

Nature always likes giving us diversity. In almost every field of science, this diversity is embraced. Except apparently when it comes to the IAU and planets, on the grounds that "I couldn't memorize them all". Well, tough luck, we're going to keep finding more and more planets under any definition, and more and more diversity, with time, you can't hold out on your "I can't memorize them all" nonsense forever.

And really, why not embrace the fact that these aren't just undifferentiated hunks of rocks? Something being large enough to reaching hydrostatic equilibrium says a lot about the object. It means you start getting all sorts of geological differentiation processes, uneven heating, localized mineralization, long timeperiods to cool down, etc. It makes them very interesting places for exploration - and for the search of for life.