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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

#61

Post by zveyaeyv3sfye »

api wrote: post #7
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…

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…

Not sure I want a black hole in my backyard ;-)

For all it's worth, there's no need to go black hole to explain the lack of visual observation. Objects that far from a star reflect very little if any light and would appear black to a black background.

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

#62

Post by s1artibartfast »

tliltocatl wrote: post #58
s1artibartfast wrote: post #55

Earlier quoted context omitted.

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.

Correct, but my point is you don't need to lose energy to enter orbit.

You don't need complex reverse slingshot interactions. You just need a low enough relative velocity to not shoot off the other side.

I would expect this to be the norm for capture, not some exotic phenomenon.

A ball doesn't need to lose energy to be captured in a valley either.

You just apply a radial force to turn a line into a circle.

Anything that approaches the sun slower than escape velocity will be captured.

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

#63

Post by Projectiboga »

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…

If it were earth mass it would be ~grapefruit size. This estimate puts object nine at 9 earth mass so maybe vollyball size or melon size? https://www.astronomy.com/science/is-planet-nine-a-black-hol...

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

#64

Post by WillAdams »

ck2 wrote: post #25
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.

There's an episode on "Space & Beyond" where they show all the planets in scale to the realworld on an actual football field. Then to show Planet 9 distance they have to get in a car and drive a few miles. That worked for me.

Yeah, when the solar system was introduced to my class in grade school, we had an outdoor excursion where the teacher brought out a golfball and place it at one end, then brought out various tiny things (noting scale was very approximate) and paced off each to show the relative distances.

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

#65

Post by margalabargala »

zveyaeyv3sfye wrote: post #61
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…

Not sure I want a black hole in my backyard ;-) For all it's worth, there's no need to go black hole to explain the lack of visual observation. Objects that far from a star reflect very little if any light and would appear black to a black background.

Black holes are no more "dangerous" than other objects of equal mass.

If a black hole with a mass of, say, Ceres hit the Earth, it would not be particularly worse than if Ceres hit the Earth.

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

#68

Post by devoutsalsa »

margalabargala wrote: post #65
zveyaeyv3sfye wrote: post #61

Earlier quoted context omitted.

Not sure I want a black hole in my backyard ;-) For all it's worth, there's no need to go black hole to explain the lack of visual observation. Objects that far from a star reflect very little if any light and would appear black to a black background.

Black holes are no more "dangerous" than other objects of equal mass. If a black hole with a mass of, say, Ceres hit the Earth, it would not be particularly worse than if Ceres hit the Earth.

I’d love see a mini-Ceres about this streaming on Nebula.

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

#70

Post by NikkiA »

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.

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.
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