I’d rather we have dozens of planets, with news articles talking about “new planets discovered”
we can still teach the handful of “classical planets”, so we can have posters, or have like periodic tables, and everyone be aware that they might go out of date as more is discoverd.
the solar system will be more exciting and more varied.
also, the “clearing orbit from similar objects” is time and orbit dependent,
larger orbits take longer to clear, which mean in a few billion years ceres might eject pluto and become a planet?
or we could have gas giants beyond pluto (like this hypothetical 9th planet ) which it would be unlikely it has cleared its orbit, so we could have a planet larger than Jupiter which we would call a planet, but if we discover another planet in its orbit (too large to clear), then we will have to say that it is a dwarf planet.
The main issue here is that everything from a speck of dust to the massive black hole at the centre of the galaxis is pretty much the same thing on a large spectrum.
You can clearly say that some grains of dust are something entirely different than a supermassive black hole, but it’s really hard to find solid cut-off points to categorize anything in between.
So we started with a handful of arbitrary examples for each category, which was easy when we only had these examples, but with more and more discoveries the gaps between these examples are filled and it becomes a spectrum, and then it becomes iffy what exactly fits into which category.
I’d rather we have dozens of planets, with news articles talking about “new planets discovered”
we can still teach the handful of “classical planets”, so we can have posters, or have like periodic tables, and everyone be aware that they might go out of date as more is discoverd.
the solar system will be more exciting and more varied.
also, the “clearing orbit from similar objects” is time and orbit dependent,
larger orbits take longer to clear, which mean in a few billion years ceres might eject pluto and become a planet?
or we could have gas giants beyond pluto (like this hypothetical 9th planet ) which it would be unlikely it has cleared its orbit, so we could have a planet larger than Jupiter which we would call a planet, but if we discover another planet in its orbit (too large to clear), then we will have to say that it is a dwarf planet.
The main issue here is that everything from a speck of dust to the massive black hole at the centre of the galaxis is pretty much the same thing on a large spectrum.
You can clearly say that some grains of dust are something entirely different than a supermassive black hole, but it’s really hard to find solid cut-off points to categorize anything in between.
So we started with a handful of arbitrary examples for each category, which was easy when we only had these examples, but with more and more discoveries the gaps between these examples are filled and it becomes a spectrum, and then it becomes iffy what exactly fits into which category.