Welcome to Steffi Mistin History Class from HouseofWorks.com

Hello and welcome to the podcast. I'm Holly Fry.

And I'm Tracy B Wilson.

And I have to confess up front that I might offend people by saying that's a little bit...

The impetus for this episode is because I can get a little cranky and fussy about people who are still campaigning to get Pluto back as a planet.

Yeah.

Future doesn't have feelings.

I don't think the people do is personally hurt by having been no longer a planet.

Well, and some of it for me is just that like there are rules and reasons.

There's still a debate that can certainly happen, but there are rules and reasons and it's explained why it was made a dwarf planet.

And people will come back and say it shouldn't matter that it's small, it's still a planet.

And it's like, hey, that doesn't have anything to do with it.

So, but we're not talking about Pluto. We've done that before.

But instead we're going to talk about some other heavenly bodies that had a similar kind of discovery,

misclassification, shift. It's kind of, you know, I wanted to talk about how like our knowledge and our...

what we believe to be true and how we lay out our knowledge of the universe and the solar system specifically changes all the time based on new information.

So, in 1800 there were only seven known planets in the solar system and at that point it was Mercury, Venus, Earth, Mars, Jupiter, Saturn, and Uranus.

Wondering if there might be a planet in between Mars and Jupiter had really taken up headspace for a lot of astronomers up to that point.

Once Uranus was discovered in 1781 by Sir William Hershel, it validated a theory that indicated that there should be sort of regular spacing between the orbital ellipses of planets.

And this gave astronomers even stronger conviction that there must be a planet there in that swath of space between Mars's orbit and Jupiter's orbit.

But no one had identified a planet there. Johannes Kepler even theorized about a planet in that gap between those two planets in 1596 in his work Mysterium Cosmographicum.

And he actually hinted that there would be more than one there writing, quote, yet the interposition of a single planet was not sufficient for the huge gap between Jupiter and Mars.

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