Comments on MSS: Ep 128: Another demotion for Pluto? Or is it about...

Spin and counter-spin on how we view Pluto? We kno...

2010-05-18T23:01:06.120+10:00

Spin and counter-spin on how we view Pluto? We know so little of the Universe now, that once we know more, this debate over Pluto may seem whimsical and totally unimportant.

Our solar system definitely has more than 13 plane...

2010-05-08T04:06:42.857+10:00

Our solar system definitely has more than 13 planets. Thirteen is the current number if one counts those objects officially designated as dwarf planets among the total planet count. Advocates of counting dwarf planets as a subclass of planets fully expect that when all the dwarf planets are properly designated as such, the planet count in our solar system will be 50, 100, or more. The point is, we have no problem with that.

I'm "attached" to Pluto? It's more like I'm committed to overturning the wrongful IAU demotion, which was a political rather than a scientific decision. I am committed to promoting a geophysical definition of planet although I respect dynamics as well. I don't care about my pagerank; in fact, I don't even know how to calculate it or if LiveJournal, where I have my Pluto Blog, has a provision for doing this. The only thing I care about is making sure people know that there are still two legitimate views on the Pluto issue.

Media articles are often republished, along with repeats of the same statements. In this case, the media for some reason jumped on the fallacy that having more planets equals a further demotion for Pluto. It does not, and I will do whatever I can to counter that spin.

Thanks for the update - I did not know that Pluto ...

2010-05-07T20:47:17.680+10:00

Thanks for the update - I did not know that Pluto had been demoted! Poor Pluto :(

That's great timing as J just started learning about constellations and planets.

We are having a space/astronaut party for his birthday. You should come - got any space tricks?

Marc, you are such a b*tch.

2010-05-07T20:40:14.184+10:00

Marc, you are such a b*tch.

Thanks for your comments Laurel. I notice from a q...

2010-05-07T11:16:22.201+10:00

Thanks for your comments Laurel. I notice from a quick Google search that clearly you are attached to Pluto and have been pasting these exact comments all over the place! I hope your pagerank increases...

I would recommend you listen to the show, and read this article a bit closer. This article and podcast are about "hydrostatic equilibrium" - this research probably supports your position.

In any case, under your definition, our solar system would have over 50 planets - not the 13 you mention here.

Thanks also for the almost exact same comments on the 365 days of astronomy show I produced, and our other show on Pluto. I'll leave them up as the promote debate, but they are copy and pasted and show that you didn't listen to the shows.

Adding more dwarf planets is in no way another dem...

2010-05-07T06:47:34.428+10:00

Adding more dwarf planets is in no way another demotion for Pluto. The reason is that in spite of the controversial IAU decision, dwarf planets are planets too. Dr. Alan Stern, who coined the term, intended it to refer to a subclass of planets large enough to be in hydrostatic equilibrium (pulled into a round shape by their own gravity) but not large enough to gravitationally dominate their orbits. He never intended dwarf planets to be designated as not planets at all. And he said he anticipates there being hundreds of these small planets in our solar system.

Adding more dwarf planets is in no way another demotion for Pluto. The reason is that in spite of the controversial IAU decision, dwarf planets are planets too. Dr. Alan Stern, who coined the term, intended it to refer to a subclass of planets large enough to be in hydrostatic equilibrium (pulled into a round shape by their own gravity) but not large enough to gravitationally dominate their orbits. He never intended dwarf planets to be designated as not planets at all. And he said he anticipates there being hundreds of these small planets in our solar system.

Only four percent of the IAU voted on this, and most are not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. Stern and like-minded scientists favor a broader planet definition that includes any non-self-luminous spheroidal body in orbit around a star. The spherical part is important because objects become spherical when they attain a state known as hydrostatic equilibrium, meaning they are large enough for their own gravity to pull them into a round shape. This is a characteristic of planets and not of shapeless asteroids and Kuiper Belt Objects. Pluto meets this criterion and is therefore a planet. Under this definition, our solar system has 13 planets: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris.