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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

#241

Post by science4sail »

gonzobonzo wrote: post #129
db48x wrote: post #88

Earlier quoted context omitted.

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 mo…

I thought that there were only four planets? Jupiter, Saturn, Uranus, Neptune

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

#242

Post by colechristensen »

im3w1l wrote: post #192
Dylan16807 wrote: post #172

Earlier quoted context omitted.

> A black hole bright enough to see its hawking radiation has to be tiny and would be quite short lived with an origin of unknown mechanism. Depends on what distance you want to see it from. A black hole that glows as hot as an incandescent filament would have as much mass as a 250km cube of rock and it would last for 10^35 years. It would have a radius of 60nm and emit less than a microwatt. > a black hole small eno…

A long lasting object emitting 10gw could make for a nice power plant...

The problem is of course constructing one, and unfortunately at the point you could it would no longer be even a little interesting.

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

#243

Post by im3w1l »

colechristensen wrote: post #242
im3w1l wrote: post #192

Earlier quoted context omitted.

A long lasting object emitting 10gw could make for a nice power plant...

The problem is of course constructing one, and unfortunately at the point you could it would no longer be even a little interesting.

What would you rather use for energy when you are at that point?

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

#244

Post by mbfg »

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.

how about 4 times further than Voyager 1?

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

#245

Post by mock-possum »

api wrote: post #216
shiandow wrote: post #53

Earlier quoted context omitted.

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

I recall reading years ago some speculation that the Tunguska event may have been an encounter with such an object. A micro black hole traveling at tremendous velocity would go right through the Earth and keep going, but as it encountered the atmosphere it might emit a bunch of ultra high energy gamma rays (due to accretion) that set off fusion reactions and create an airburst. From there it would shoot right through…

It’s a fun idea - I vaguely remember listening to an NPR show / podcast on the subject last year.

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

#247

Post by snthpy »

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 agree. Idk now many AUs Pluto is but I know it's far away and hardly visible until we flew by.

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

#248

Post by YeGoblynQueenne »

iamthemonster wrote: post #211
alex_duf wrote: post #205

700 times further => isn't it farther rather than further? Non native english speaker here, but last I checked further was a metaphorical distance, when farther was a literal distance. You can push a concept further, but you walk farther right? Or did I miss something?

You speak English too well - you have surpassed English speakers. None of us know the difference between further and further.

They're the same :P

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

#249

Post by goku12 »

viraptor wrote: post #215
goku12 wrote: post #196

Earlier quoted context omitted.

> As long it is orbiting the sun The body must also be large enough to clear other bodies in the same orbit, except at the Trojan positions (L4 and L5), to be considered as a planet. Otherwise it would just be a Trans-Neptunian Object (TNO) or a Kuiper Belt Object (KBO) at these distances. It obviously does in this case. But this pedantic detail is rather important. It was used to demote Pluto a few years back.

> It obviously does in this case. Does it? Would we actually know if there was another slightly more sparse belt at 700AU? If we can't track a large planet in that area, why would we be certain about the belt? Alternatively, if it's an external object captured by the Sun, how would we even classify it as clearing or not if there's nothing to clear?

Well, apparently the object causes bunching of other bodies in the Kuiper belt. And it would have got enough time to complete a few orbits. I assume that at some point, the other objects on its orbit would have been thrown off course or consumed by the planet.

> how would we even classify it as clearing or not if there's nothing to clear?

I assume that it's based on mathematical modeling.

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

#250

Post by rietta »

My lay scientist feel is still that Pluto is a planet, or at the very least have been grandfathered in. The New Horizons reporting 10 years ago just solidified this in my mind. The geological processes are more telling than having cleared the orbital neighborhood. That would just mean that get far enough out and nothing can be a planet no matter how massive. All that said, this massive of an object that far out is very interesting. It would be a very, very cold out there. Would even a gas giant be a solid at that distance? Are there any geological processes possible?
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