Today ten years ago an IAU resolution stated an official definition for the term “planet” who ultimately excluded Pluto as a planet of our Solar System, and reclassified it as “dwarf planet”.
Image via NASA: What Is Pluto? Caption: The New Horizons spacecraft helped us see Pluto and its largest moon Charon more clearly than we could see them with telescopes.
A Euler diagram showing the relationship between objects in the Solar System (excluding stars) – Wikimedia Commons
huh, so what we were taught in school were actually Euler diagrams, but *called* Venn diagrams for some reason
Yeah, technically a Venn diagram shows all possible intersections. The ones that are empty are sometimes shaded black, but they’re there regardless. Silly wikipedia image showing Venns morphing into Eulers:
#anniversaries #(apparently this was on the 24th) #Pluto #today I was reading about the outer solar system in my astronomy textbook #2014 edition #there was a remnant Pluto section in the ”outer planets” section basically explaining #why Pluto was no longer considered a planet and would be described in more detail in the ”other solar system bodies” chapter #it referred to the New Horizons fly-by in the future tense #there were no pictures #because nobody had ever seen what Pluto looked like #(the educational video next on my to-do list tomorrow was made in 2006) #(I think I already caught them re-dubbing a previous section involving Pluto) #(the picture showed nine planets orbiting the sun) #(while the voiceover) #(which–while the same narrator as the rest of the series–didn’t sound like it was quite of a piece with the rest of the narration) #(talked about eight planets and oh yeah there’s a dwarf planet in here too) #((I’m *probably* overstating that last bit but anyway)) #adventures in University Land
Brinens and Things 
