Pluto Demoted Day 2021 is on Tuesday, August 24, 2021: What have you got planned for 'Pluto Day' ?


Tuesday, August 24, 2021 is Pluto Demoted Day 2021. PLUTO DEMOTED DAY Today is PLUTO DEMOTED DAY.

What have you got planned for ’Pluto Day’ ?

Being discovered by an American doesn't make Pluto an American planet, any more than Neptune is a German planet. Also, as Geoff points out, all the planets have their own symbols.

Pluto isn't qualified to be represented on the flag because it isn't a state. It has no residents, for a start, and hasn't petitioned Congress for admission into the Union.

Still, I've always had a sneaking fondness for Pluto, and personally I'm glad the New Horizons probe was sent before it was demoted to Dwarf status. I can't wait till it gets there!

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So is Pluto officially not a planet anymore?

So is Pluto officially not a planet anymore?

Pluto was declassified from planet to a Dwarf Planet in 2006. The reason for it was simple: Before 2006, there was no formal definition what a planet is. We just used stomach feeling for grouping things into categories. Pluto became a planet, because the discoverer thought it was. Ceres became no planet, because it was in the asteroid belt and must be an asteroid that way.

In the end of the 20th century, we discovery more and more objects around Pluto and behind it, for example an object which was even larger than Pluto, today called Eris, and we found out that Pluto is inside a cloud of many smaller objects, now called Plutinos.

For handling the new discoveries, and finally solve the lack of a definition, the astronomers of the world met in Prague and had to choose between many different definitions.

Finally, they decided to use Planet only for objects, which are not only huge, but also dominate their orbital region with their gravity. Pluto, Eris and Ceres became Dwarf Planets, large enough to be almost spherical, but not large enough to dominate their orbital region. This group grew by the addition of Haumea and Makemake.

Is it fair to demote Pluto to the second division?

Is it fair to demote Pluto to the second division?

I want to keep Pluto a planet. That said, I'm sure there are people who once said, 'I miss the days when we thought the earth was flat,' or 'Remember when we thought the sun revolved around the earth? That was better.'

They're voting on it on August 24. I think this is rather significant, and more interesting than the world news, which is a nightmarish mess. I guess we're lucky that these days astronomers hold colloquia to decide these ticklish questions as our awareness of the solar system grows. Back in the good old days, they would put you under house arrest. But it really does shake up one's established perception of the universe.

The new lineup in the solar system is potentially:

Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon, and Xena (the provisional name for 2003 UB313)

Someone come up with a sentence:


I don't know what unnerves me more, the fact that Ceres has been added between Mars and Jupiter or that they want to get rid of Pluto, or that they want to add Charon, or 2003UB313, nicknamed Xena by the guy who discovered it. They don't like Xena, and will probably change it to something stupid. If there are another 20-30 planets beyond that, I think they should hold a massive internet public vote to name them.

Also on this date Tuesday, August 24, 2021...