So, if the earth is flat then it would not be a planet anymore...
Keiichi pointed and asked, “What’s that one?”
His guide expkained, “That is the dwarf planet Ceres. It was formerly called an asteroid. It is the largest object in the asteroid belt that lies between Mars and Jupiter.”
“A dwarf planet? It’s not an asteroid anymore?”
“No. It was because around 2007 the International Astronomical Union (IAU) had a little problem. You see, astronomers kept discovering more and more large objects floating in the Kuiper belt, the region of space beyond the planet Neptune. Astronomers have so far found over 1000 of these Kuiper Belt Objects (KBOs), including some rather large ones, such as Sedna, Quaoar, Orcus, Haumea, Makemake, and Eris. That last one, Eris, is actually larger than Pluto itself. So the number of planets in the solar system threatened to grow ever larger: 10 planets, 12, 13? Where do you stop?”
“Yeah, sounds like a problem. What did the IAU do?”
“They busted Pluto down to ‘dwarf planet’ status. A dwarf planet is defined as a solar body whose gravity is large enough to mold itself into a spherical shape, and it is not the moon of another satellite, but it is not large enough to clear out all of the debris in its own orbit. Pluto is basically just another Kuiper Belt object. A dwarf planet.”
“So that’s why Ceres got promoted from asteroid to dwarf planet too, because it’s large enough to be round.”
“So round is the determining factor?”
“Yep.”
I don’t have a ‘side’ in the fight; but it is interesting to me how so many of us were strangely disturbed to have our understanding of the planets, inculcated since childhood, all interfered-with.
Mike Brown actually received ‘hate mail’ over this ;-)
So, if the earth is flat then it would not be a planet anymore...