Planet Nine: 'Insensitive' Term Riles Scientists
The International Astronomical Union (IAU) famously reclassified Pluto as a "dwarf planet" in 2006. That decision remains highly controversial today, as made clear by the new note, which appeared in the July 29 issue of the Planetary Exploration Newsletter.
The note:
ON THE INSENSITIVE USE OF THE TERM "PLANET 9" FOR OBJECTS BEYOND PLUTO
We the undersigned wish to remind our colleagues that the IAU planet definition adopted in 2006 has been controversial and is far from universally accepted. Given this, and given the incredible accomplishment of the discovery of Pluto, the harbinger of the solar system's third zone — the Kuiper Belt — by planetary astronomer Clyde W. Tombaugh in 1930, we the undersigned believe the use of the term 'Planet 9' for objects beyond Pluto is insensitive to Professor Tombaugh's legacy.
We further believe the use of this term should be discontinued in favor of culturally and taxonomically neutral terms for such planets, such as Planet X, Planet Next, or Giant Planet Five.
35 researchers signed the note, including Alan Stern, principal investigator of the New Horizons mission.
Of more interest may be this proposal concerning future exploration of Uranus and Neptune:
Related: Uranus and Neptune Are Potential Targets for 2030s Missions
Another Trans-Neptunian Object With a High Orbital Inclination Points to Planet Nine
CU Boulder Researchers Say Collective Gravity, Not Planet Nine, Explains Orbits of Detached Objects
Planet Nine Search Turns Up 10 More Moons of Jupiter
(Score: 2) by AthanasiusKircher on Thursday August 02 2018, @07:25PM (1 child)
Also, to show that I'm really agnostic on this, here's an interview with a real planetary scientist [space.com] (one of the guys who actually proposed the first metric for clearing the neighborhood) about why he thinks the IAU definition is bad.
Point being: the IAU definition of a "planet" may or may not be a good one by various criteria, but "clearing the neighborhood" is a real thing and a potentially interesting attribute of a body.
(Score: 4, Informative) by requerdanos on Friday August 03 2018, @02:33PM
That isn't obvious, to be honest.
Whether you are agnostic, or a God named after a planet, the fact is that the argument under discussion is that if the rules indicate that a big semi-spherical gas giant "yes" is a planet at 5 astronomical units, but the identical big semi-spherical gas giant "no" is not a planet at 55 astronomical units while orbiting the same star, and the rules do indicate this, then that's an interesting feature of those rules.
But wait, what if you really carefully and scientifically look for things existing planetary bodies have in common, like (mostly) clearing their orbits? Does that change the fact that Juipter counts "yes" as a planet at 5AU but "no" would not count at 55AU?
No, it doesn't change that fact, so going on about how careful, cool, or earth-shatteringly awesome orbit-clearing is, doesn't show you to be "Agnostic"--it just shows that you're missing a valid point that would be interesting for discussion.
With all due respect, while that's a point, it's not the point under discussion in this thread. No one is saying that orbit-clearing is not a real thing, nor that it's uninteresting; just observing that it would only apply to planets within a certain radius from the Sun.
That is relevant here (unlike orbit-clearing monomania, which isn't) because we are talking about the possible existence of a big semi-spherical thing in orbit around the sun that is really really far out compared to the other ones (which we call planets, dwarf planets, etc.). We're calling the posited far-out body "[Ice [Giant]] Planet (3|5|9|X|etc.)". In talking about such a body, the point comes up that even if it's identical to one of the other bodies that firmly count as "planets", it may very well itself not count because at a more distant location it might not have things in common, like--you guessed it, or failed to--orbit-clearing of its much larger-diameter orbit.
I get that you appear unhappy about that, and that orbit-clearing seems important to you. Those things don't make this apparent contradiction within the rules uninteresting nor irrelevant--in this context, it's especially interesting and relevant.