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A 1980s space telescope may have seen planet nine

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101–110 of 137 posts

Re: A 1980s space telescope may have seen planet nine

#102
post #76

Earlier quoted context omitted.

My favorite example of this is that trees aren’t really a phylogenetic group all their own. They’re just plants and plants can become tall and woody with a few genetic tweaks. You can’t trace trees to a common ancestor because the ancestors of many types of trees are just ordinary plants. https://eukaryotewritesblog.com/2021/05/02/theres-no-such-th...

Same goes for fish, which I just read in the excellent book "Why Fish Don't Exist" by Lulu Miller. An example being that a lungfish has more attributes similar to a cow than to a salmon.

> An example being that a lungfish has more attributes similar to a cow than to a salmon.

Such as?

Re: A 1980s space telescope may have seen planet nine

#105
post #99
post #27

Earlier quoted context omitted.

"A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite." According the the wrong-headed AIU definition. So, yes, _Jupiter_ could be a dwarf planet, if it hasn't cleared it's o…

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood Weird definition since it prevents deciding if an exoplanet is a planet or a dwarf planet. It smells like a compromise proxy measure for: orbital stability, in a reasonably circular orbit, plus rule out Pluto. Maybe there is some deep reason for using that measure, but it is not obvious.

As far as I can tell, many planetary scientists aren't particularly fond of the definition either. I believe the initial plan that the IAU had after the discovery of Eris was to classify dwarf planets as planets, but some of the members didn't like the idea that our solar system would suddenly get a lot more planets, so pushed for the current awkward and ill-defined IAU definition.

Though there are a lot of people that present the IAU definition as if it were simply the will of "science," if you look at the 2006 debate about it amongst scientists, it was actually fairly contentious.

Re: A 1980s space telescope may have seen planet nine

#106
post #64
post #3

Mike Brown recently wrote a summary of his and Konstantin Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper belt objects (KBOs) whose orbits appear skewed by the invisible gravity of a possible Planet Nine, accounting for observation bias, and running a ton of simulations and MCMC, they concluded: if it exists, Planet Nine has a mass of 6.2 (+2.2/-1.3) Earth masses and a perihelion (closest approach to…

I’m just mad we’re losing out on “Planet X”. When I was a kid Pluto was a planet so the new one was X (10) and it was cool. Now this new planet is just going to be planet 9 again… totally lame.

Oh man this was me! I 100% agreed until I saw relative size of Pluto[0].

Definitely seems unfair to call it a planet when there's a number of Kuiper belt objects that are larger[1](?) or pretty much the same size.

[0] https://www.quora.com/Why-is-Pluto-so-different-from-the-oth...

[1] https://www.universetoday.com/118118/it-looks-like-these-are...

Re: A 1980s space telescope may have seen planet nine

#107
post #4
post #3

Mike Brown recently wrote a summary of his and Konstantin Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper belt objects (KBOs) whose orbits appear skewed by the invisible gravity of a possible Planet Nine, accounting for observation bias, and running a ton of simulations and MCMC, they concluded: if it exists, Planet Nine has a mass of 6.2 (+2.2/-1.3) Earth masses and a perihelion (closest approach to…

Also, Mike Brown's free 'The Science of the Solar System' course on Coursera is excellent. Highly recommended. https://www.coursera.org/learn/solar-system

Excellent suggestion!

Re: A 1980s space telescope may have seen planet nine

#108
post #52

Earlier quoted context omitted.

If by “whole world” you mean the wilderness, then sure! Otherwise we’ve had no issues laying cables to any place people live, so long as it makes sense to do so.

If by "makes sense" you mean to ISP shareholders - for ISPs to take federal USF funds and never, ever deliver on the required upgrades or expansions (eg:Frontier@WV,Verizon@PA), due to regulatory capture.

I’m not going to be the one to defend the actions of a group of my least favorite companies in America, but you hit on the main point that stands up globally: where it is profitable to lay cables down. So yes, where it makes sense to shareholders.

That’s not to discount Starlink, it is a comparative advantage to be able to cover the wilderness, but that and not being an existing ISP people have had lots of experience with are its distinguishing features.

Re: A 1980s space telescope may have seen planet nine

#110
post #41

Earlier quoted context omitted.

Isn’t that bigger news than it sounds at first? Part of the problem of finding planet nine must be knowing where it currently is on its orbit. A few possible observations should help to narrow down the space in which to look for it by a lot (rather: would make it almost clear where it currently is). Maybe JWST could be of help with testing the hypothesis that these early infrared observations of a moving object were…

Would have commented this same thing. It should be a matter of translating the coordinates into a search pattern to look at with JWST.

Every millisecond on JWST is booked years in advance already. Unless Planet 9 searchers turn up with some good guesses and not just a search pattern, other research with far more likelyhood of success has priority.
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