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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

#51

Post by noah_buddy »

01HNNWZ0MV43FF wrote: post #40
libraryofbabel wrote: post #38

Earlier quoted context omitted.

The other planets formed from material in the same nebula (cloud of gas and dust) that collapsed to form the sun. The idea here is this planet would have been moving through the interstellar medium and just happened to pass close enough to the sun’s gravity well to get captured in a (very distant) orbit.

Capture would be like a reverse gravitational slingshot? This planet happened to meet the sun at an angle where it lost enough energy to fall into orbit instead of slinging back out like those comets that come around on long cycles?

A comet coming back on a long cycle is an orbit

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

#52

Post by [deleted] »

api wrote: post #21
TheOtherHobbes wrote: post #16

Earlier quoted context omitted.

I really hope it isn't true because if there's one out there, there will be others, and I'd rather not meet one in person. We don't have enough data to see whether there are unexpected instabilities in detected planetary systems. But it would be an interesting project to look for those.

They're not dangerous unless you get too close. A black hole is not a cosmic vacuum cleaner. If the Moon were suddenly transformed into a tiny black hole with the same mass, it would continue to orbit the Earth at the same distance. Ocean tides due to its gravity would continue normally. There would not be much effect except that it would no longer be visible with the naked eye and would no longer reflect the sun's l…

[deleted]

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

#53

Post by shiandow »

TheOtherHobbes wrote: post #16
api wrote: post #7

Earlier quoted context omitted.

I really hope this is true, because it would mean there is a black hole close enough it could be examined and studied. This might allow us to test physics ideas that can’t be tested any other way, and maybe even to “finish” physics. It could also allow gravity and Oberth effect acceleration of small probes to meaningful fractions of the speed of light for interstellar flyby missions. Imagine the Oberth effect boost f…

I really hope it isn't true because if there's one out there, there will be others, and I'd rather not meet one in person. We don't have enough data to see whether there are unexpected instabilities in detected planetary systems. But it would be an interesting project to look for those.

Running into a rogue black hole must be far less likely than an extinction level impact with a relstively boring big rock.

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

#54

Post by s1artibartfast »

swayvil wrote: post #48
tliltocatl wrote: post #35

Earlier quoted context omitted.

The rest of the planets are theorized to have condensed from the protoplanetary disk that formed the same molecular cloud the Sun did. I. e. they have formed at approximately same time as the sun and from same material, sans gravitational separation.

Ah, so a captured body would be quite different and alien. Really old too. Like, first generation of stars.

Not at all implied. It could be boring and younger too.

10x earth masses usually implies a gas giant.

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

#55

Post by s1artibartfast »

01HNNWZ0MV43FF wrote: post #40
libraryofbabel wrote: post #38

Earlier quoted context omitted.

The other planets formed from material in the same nebula (cloud of gas and dust) that collapsed to form the sun. The idea here is this planet would have been moving through the interstellar medium and just happened to pass close enough to the sun’s gravity well to get captured in a (very distant) orbit.

Capture would be like a reverse gravitational slingshot? This planet happened to meet the sun at an angle where it lost enough energy to fall into orbit instead of slinging back out like those comets that come around on long cycles?

You don't need to lose energy to enter orbit any more than you need to lose energy too roll a ball down a hill.

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

#56

Post by ufo »

sph wrote: post #26
perihelions wrote: post #15

This cannot be evidence of Planet 9 (the Batygin and Brown hypothesis)—it's outright incompatible with it. https://bsky.app/profile/plutokiller.com/post/3lnqm2ymbd22r If those two spots are the same object, that object is on a high-inclination orbit; but the pattern the Planet 9 hypothesis explains is only compatible with a low-inclination object.

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?

His team discovered Eris and many other trans-neptunian objects, which did fuel the discussion behind pluto's demotion: greatly increase the number of planets, or demote pluto? They're also behind the Planet 9 theory that's discussed in the article.

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

#57

Post by ta1243 »

kiba wrote: post #42
api wrote: post #7

Earlier quoted context omitted.

I really hope this is true, because it would mean there is a black hole close enough it could be examined and studied. This might allow us to test physics ideas that can’t be tested any other way, and maybe even to “finish” physics. It could also allow gravity and Oberth effect acceleration of small probes to meaningful fractions of the speed of light for interstellar flyby missions. Imagine the Oberth effect boost f…

We could use the black hole to power our civilization due to how efficient it is for generating power.

No need for something that exotic. The Earth alone receives more energy from the sun every hour than mankind uses each year.

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

#58

Post by tliltocatl »

s1artibartfast wrote: post #55
01HNNWZ0MV43FF wrote: post #40

Earlier quoted context omitted.

Capture would be like a reverse gravitational slingshot? This planet happened to meet the sun at an angle where it lost enough energy to fall into orbit instead of slinging back out like those comets that come around on long cycles?

You don't need to lose energy to enter orbit any more than you need to lose energy too roll a ball down a hill.

Not true. An obit is not an infinite "plain" with a finite "hill" on but rather a finite "valley". The ball will exit the valley on the other side unless it loses excess kinetic energy somewhere in the valley.

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

#59

Post by ta1243 »

irrational wrote: post #44
gus_massa wrote: post #18

Earlier quoted context omitted.

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...

I would add those to the list of official planets, yes. Don’t remove Pluto, add the rest.

So that makes Pluto the 10th planet an Neptune the 9th planet.

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

#60

Post by [deleted] »

swayvil wrote: post #48
tliltocatl wrote: post #35

Earlier quoted context omitted.

The rest of the planets are theorized to have condensed from the protoplanetary disk that formed the same molecular cloud the Sun did. I. e. they have formed at approximately same time as the sun and from same material, sans gravitational separation.

Ah, so a captured body would be quite different and alien. Really old too. Like, first generation of stars.

[deleted]
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