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Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

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Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#121

Post by deadbabe »

randomtoast wrote: post #6

I find one theory regarding Planet 9 especially interesting, and that is that it could be a primordial black hole with a Schwarzschild radius on the order of just a few centimeters. So basically, just a golf ball-sized black hole. This would explain why we can see the gravitational effects on the other objects as described in many papers, and it would also explain at the same time why we have no direct observation of…

Any chance we could use this black hole as a really powerful slingshot by getting very close right before passing the event horizon and then firing off into space?

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#122

Post by xattt »

rootsudo wrote: post #118

When did Planet X become planet 9? Is it because Pluto was a planet and now no longer is so the X was really a Roman numeral vs a variable (if)?

The article explains that Planet X is a possible explanation for the apparent regularity of mass extinction events. Planet 9 is a separate concept to explain the bunching of Kuiper Belt objects, like Sedna.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#123

Post by AIPedant »

dragonwriter wrote: post #111
AIPedant wrote: post #98

Earlier quoted context omitted.

It makes even less sense for Earth because Earth's orbit is near-circular, whereas Planet 9's hypothesized orbit is highly eccentric, more so than Pluto. Most people don't know off-hand that Pluto is ~40-50AU from the sun, so 700AU is hard to conceptualize.

> Most people don't know off-hand that Pluto is ~40-50AU ~30-50AU if you are referring to the range of orbital distance.

No, I was referring to the range of my recollection when I read Wikipedia earlier this morning while writing the parent comment :)

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#124

Post by jodrellblank »

gus_massa wrote: post #18
metalman wrote: post #3

we already have a 9'th planet, but due to the greatest pedantic campain of all time, pluto got demoted. Though given the current situation, ha!, that could change.....perhaps the naming commity will get noticed, and be offered a chance to do a deal, and Make Pluto A Planet Again,(MPAPA)

If you add Pluto, you must add also Eris and a few more, like 5 or more, and perhaps also Ceres. Here is a nice graphic that excludes Ceres https://en.m.wikipedia.org/wiki/Dwarf_planet#Population_of_d...

> "If you add Pluto, you must add also Eris"

Nonsense. "Pluto is grandfathered in as a planet, nothing else is a planet". See?

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#125

Post by ednite »

snapetom wrote: post #119
ednite wrote: post #82

Earlier quoted context omitted.

Not sure why the downvotes—if I came off wrong, my apologies. I genuinely meant it in a humoristic way. I'd honestly love to see a probe launched into a black hole.

We don't do humor here, and I'm not kidding. Humor devolves the site into useless one liners. If you want evidence of that, go to reddit and see how useful that site is these days if you want to actually research and learn something. Slashdot knew this back in the day and while funny posts got visibility, they did not add anything to a user's total karma score.

Fair enough--I'll be more mindful next time. Thanks for letting me know.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#126

Post by zamadatix »

AIPedant wrote: post #98
NikkiA wrote: post #70

Earlier quoted context omitted.

I dunno, '700 AU' gelled for me instantly, '15 times the distance to pluto' doesn't even make sense given pluto's orbit isn't anywhere near circular.

It makes even less sense for Earth because Earth's orbit is near-circular, whereas Planet 9's hypothesized orbit is highly eccentric, more so than Pluto. Most people don't know off-hand that Pluto is ~40-50AU from the sun, so 700AU is hard to conceptualize.

They're all horrible to conceptualize because people don't commonly deal with how far even something like the Earth to the Sun is, I don't think there is any winning answer here - at least an AU is consistently defined and maybe slightly more likely to be familiar, but it's still just about as crap to be honest.

Side note: Apart from AU already being defined as average distance and not current distance, the distance referenced is how far out the proposed object is now, not its general orbital parameters. At that orbital distance 23 years of motion isn't going to be much change in distance even if it's in a hyperbolic orbit.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#127

Post by K0balt »

jsbisviewtiful wrote: post #47
K0balt wrote: post #24

I hope this turns out to be wrong. I’m still holding out for a primordial back hole Planet X. That would be soooo cool and unbelievably useful.

Why useful? Considering how hard of a time astronomers are having to simply find it it’s hard to imagine it being easy to study.

Aside from research, it could be used to provoke time dilation, though I’m not sure how much you could get out of a basketball sized black hole.:8

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#128

Post by api »

XorNot wrote: post #114
api wrote: post #41

Earlier quoted context omitted.

It’s an object with theoretical maximum density. That’s one way to think about it. Another visualization: if you had an Earth mass black hole with a solid shell surrounding it at the same radius as the Earth’s surface is from its core, gravity atop that shell would be 1g. The actual black hole would be about the size of a marble. If you got close to it you would of course be subject to insane gravity and be “spaghett…

They're also interestingly one of the most boring: every black hole can be described by 3 numbers: mass, spin and charge. Which is to say they are extremely high entropy.

They are extremely high entropy as far as what's accessible. We don't know what's really on the inside.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#129

Post by gonzobonzo »

db48x wrote: post #88
sph wrote: post #26

Earlier quoted context omitted.

The guy killed Pluto and still he isn't done :( Seriously though, is he one of the people responsible for Pluto's demotion to dwarf planet?

Nobody killed Pluto. Back in the early 1800s children used to memorize the names of the 12 planets: Mercury, Venus, Earth, Ceres, Pallas, Juno, Vesta, Mars, Jupiter, Saturn, Uranus, and Neptune. But then in 1845 astronomers discovered Astraea, and now there were 13. In 1847 three more were discovered: Hebe, Iris, and Flora. Then Metis, Hygiea, Parthenope, and Victoria by 1850. The 100th asteroid was discovered in 186…

> Nobody should force schoolchildren to memorize them all. Just tell them that there are an unknown number of objects in the Kuiper belt and the Oort cloud and they’ll know as much as they need to know.

Or just tell them that there's an unknown number of planets in the solar system, but the big 8 are the only ones they're expected to memorize. That was actually the original plan by the IAU, and how many (I believe most) planetary scientists define planet today.

The decision being based mainly on not wanting to add newly discovered planets to the list of planets in the solar system always rubbed me the wrong way. As is the tendency for people to mistakenly believe that this is settled science, when it's actually an unsettled nomenclature debate.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#130

Post by fallingknife »

rainsford wrote: post #81
AIPedant wrote: post #11

I think “15 times further from the Sun than Pluto” is more meaningful for most readers than “700 times further from the Sun than Earth.” If it exists, it’s way way way out there.

It's sort of amazing to me that the Sun can capture objects that far away. Like obviously even at that distance the Sun would be by far the closest massive thing, but it's hard to comprehend the effects of gravity being strong enough at that distance. From "Planet 9" the Sun probably wouldn't significantly stand out from all the other stars in the sky, yet you'd be orbiting it.

From 700 AU you would still be only 0.01 ly from the sun, or 400x closer to the sun than the second closest star.
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