[ad_1]
Here is a transcript of the video.
Narrator: In the 1990s, most people took Pluto for granted. Fast forward in 2006. Suddenly, Pluto was all the Americans were talking about. Or rather, scream. Some people were so angry that they gave death threats to astronomers.
Thierry Montmerle: People were so angry that they said that all astronomers had to be walled and hit every time.
Narrator: It's Thierry Montmerle. He is former Secretary General of the International Astronomical Union. The same organization of world astronomers that changed planet Pluto's status to dwarf planet in 2006. And today, more than 12 years later, people still have strong opinions every time you ask them: Should Pluto be a planet again?
– No.
– Yes.
– No.
– No.
– Yeah.
– Yes.
– No.
– Yes.
– I'm not really sure I have an opinion on whether Pluto is a planet or not.
Narrator: Obviously, there is some confusion. So we made the next logical step. We went to see the experts to fix this once and for all.
It's Alan Stern. He leads NASA's New Horizons mission, piloted by Pluto in 2015.
Alan Stern: And in planetary science, where planetary experts are, we call the small planets "planets". We call the big moons "planets". We call all planets around other stars "planets". And the definition of the astronomer does not allow any of these to be planets.
Narrator: OK, so Stern says it depends on the context. But why? In the early 90's, Pluto was a planet, period. No context necessary. So what has changed? By the end of the 90's, it had become apparent that Pluto was not alone. Astronomers had discovered other worlds in the same region, called Kuiper Belt. And some of them looked terribly like Pluto. Then in 2005, astronomers discovered Eris, who was estimated to be even bigger than Pluto.
Mike Brown: On January 8th of this year, while browsing old data that we had taken with the Samuel Oschin telescope at the Palomar Observatory, we found, to our surprise, an object three times farther than Pluto . This will absolutely rewrite the history of astronomy textbooks.
Narrator: And while these new worlds looked like Pluto, they were completely different from all the other planets in our solar system. Something must be done. It was clear that astronomers needed something that they had never had before: a good definition of what makes a planet a planet. As a result of these new discoveries, IAU has drawn up a checklist. A planet must orbit around the sun, have an almost round shape and have cleared its surroundings, which means that no other large object is nearby. And this last requirement takes Pluto away from Team Planet. Yes, it revolves around the sun. Yes, it's spherical. But Pluto is not always the dominant gravitational force in its neighborhood. On the one hand, Eris shares the area and is not stuck in the orbit of Pluto. The final result? Pluto has gone from "planet" to "dwarf planet". Stern argues that a dwarf planet is a kind of planet. Just like
Back: Bonsai is always a tree. And a Chihuahua is always a dog.
Narrator: But other experts, like Montmerle, prefer to consider dwarf planets as their own class. So where are we? Well, in the grand scheme of things, it does not matter the official designation of Pluto.
Montmerle: If people do not like it, they do not use it, one point is everything.
Narrator: Which is exactly what planetary scientists do.
Back: So everyone uses the definition of the planetary scientist in written and directed scientific literature. And use it on the podium to make scientific presentations. This is the kind of consensus that is very powerful in science.
Narrator: So maybe Pluto is not a planet in the same way that Earth and Jupiter are planets. But that does not mean we should ignore it. In addition, this dwarf planet is not limited to the eye. The New Horizons mission discovered traces of ice volcanoes, hidden oceans.
Back: There is evidence of falling ice, floes and glaciers. Just great stuff.
Narrator: And that's right, no matter how you call it.
[ad_2]
Source link