It’s not just “a piece of aluminum and metal.” It’s an extension of ourselves, sent remotely to observe a planetary system up close in a way we can’t currently do in person. For those who designed, built, and guided it, it is their “baby” just as much as a painting or a sculpture or a novel is to the artists who…

Actually, most planetary scientists, including New Horizons principal investigator Alan Stern, DO consider Pluto to be a planet. The media completely messed up by reporting one side of the planet definition debate as fact when this is far from the case. The debate remains ongoing.

Pluto IS a proper planet. There is absolutely no reason to accept the controversial IAU vote, done by four percent of its members, most of whom are not planetary scientists but other types of astronomers. Their decision was immediately rejected in a formal petition by hundreds of planetary scientists led by New…

I agree with everything but your first sentence. Science is not determined by decree of an “authority.” Pluto didn’t stop being a planet because of a vote by 424 people, most of whom are not even planetary scientists.

This is a ridiculous and completely unscientific argument. The solar system has whatever number of planets it has, not an arbitrary number convenient for us. Additionally, there is no need for children to memorize a list of names. That way of teaching the solar system is outdated and goes back to the time when we knew…

The IAU definition is not something more specific or useful. Claiming that dwarf planets are not planets at all makes no sense and blurs the distinction between them and tiny, shapeless asteroids and KBOs.

“Planet X” is a generic term used to refer to a hypothesized but undiscovered planet. It refers to the unknown, as “X” does in math, not to the number 10.

Don’t hurt—revolt! Join the many respectable planetary scientists who reject the IAU definition and consider dwarf planets to be a subclass of planets, just like terrestrials and jovians.

Nobody paid attention to Pluto until the IAU vote? First, that vote does not have the power to change Pluto’s status. Dwarf planets are still planets just like dwarf stars are still stars, and dwarf galaxies are still galaxies. Saying nobody paid attention to Pluto before 2006 is blatantly false. A large group of…

“Planet 9" is the exact opposite of an “apt name” for the hypothesized super Earth in the outer solar system. Furthermore, you fail to note that the controversial demotion of Pluto remains just one view in an ongoing debate and is not accepted or used by many planetary scientists. Pluto’s status does not depend on a…

This is not true; it is a straw man argument used in attempts to discredit opponents of the IAU defintion—who themselves specifically crafted a definition with the goal of excluding Pluto. That is hardly scientific or rational. The central argument of the pro-Pluto faction is support for a geophysical rather than…

Eris is not bigger than Pluto. It was originally thought to be so, but in late 2010, a team of scientists led by Bruno Sicardy obtained a more accurate measurement of Eris when it occulted a star and found it marginally smaller than Pluto though somewhat more massive.

It’s more massive than Pluto but not larger. According to the geophysical planet definition, both are planets because both are well beyond the threshold for being in hydrostatic equilibrium.

Mike Brown did NOT demote Pluto, yet he brands himself very unprofessionally and unscientifically as the “plutokiller” as a means of pursuing money and fame. He is not an IAU member and did not vote in 2006. He was one of a team of three that discovered Eris, and another of those three, Dr. David Rabinowitz, joined…

There are NOT only eight planets in our solar system! Why do you never question the claim that the IAU and only the IAU has the right to decide what is and isn’t a planet? That is not science; that is dogma! Only four percent of the IAU even voted on the 2006 definition, and most were not planetary scientists but…

It’s not embarrassing at all! In astronomy, new discoveries are constantly being made. It’s a given that the number of known stars, galaxies, and exoplanets is constantly changing based on new discoveries. The same is true regarding the number of planets in our solar system! Furthermore, memorization is not important…

Pluto IS a planet; it never stopped being a planet, as the IAU view represents just one position in an ongoing debate. Please do not patronize those of us who dissent with the IAU position by telling us to stop advocating a better planet definition. THAT is what is not going to happen. The IAU definition was adopted…

Please refer to this hypothetical object by the traditional term for a theorized but undisovered planet, which is “Planet X.” If it exists, it is NOT the solar system’s ninth planet. Mike Brown deliberately used this term in a press release last year as yet one more way of getting in a dig at those who oppose the IAU…

This object, Planet X, is NOT the solar system’s ninth planet, and it is not a “replacement” for Pluto; it’s an addition to a solar system whose 14+ planets include Pluto.

I have no regrets on choosing not to have kids. It’s ironic that the children of those who condemn me for this will actually have more access to the Earth’s resources because of this choice.