4 ms·

That’s a great question, and it’s (relatively) feasible to answer. The object is coming in towards the center the solar system, so its past trajectory lies out

That’s a great question, and it’s (relatively) feasible to answer. The object is coming in towards the center the solar system, so its past trajectory lies outwards. If it has been disturbed into this path from a hypothetical sun-centered orbit, it would have to have happened very recently: otherwise it would be long gone, never to return. So it would be necessary for the back-projected trajectory to pass very close to a compact, massive object. Dare I say that the vast majority of all such massive objects in the solar system are well known; so if the trajectory doesn’t indicate a close encounter with a planet within the past decade or so, then this possibility is essentially eliminated.

SI_Rob 7y ago
That, or a spare comet prop accidentally dropped from the Oort catwalk that surrounds our solar-system-scale Truman Show /s
jbattle 7y ago
There was a recent paper that showed it is possible planet 9 is a primordial black hole - would that work? https://phys.org/news/2019-09-planet-primodial-black-hole.html https://phys.org/news/2019-09-planet-primodial-black-hole.ht...
- SiempreViernes 7y ago
  No, that paper says "What if Planet 9 is a Primordial Black Hole?" and then works out some consequences and finds them to be not ruled out. It doesn't start from observations and arrive at the PBH in any natural way. To judge for yourself hour serious the authors are in proposing a primordial black hole to explain the anomalies in the outer asteroid belt, I refer you to figure 1 in their paper: https://arxiv.org/pdf/1909.11090.pdf https://arxiv.org/pdf/1909.11090.pdf
  - red75prime 7y ago
    Would you pass an opportunity to include illustration of an astronomical object at a scale of 1:1?
    - trentlott 7y ago
      I stared at that figure for about a minute and wondered at how friggin' satisfied they have to have been about it. It was and is really neat, even if the likelihood of its reality is low.
  - jbattle 7y ago
    Right - that's why I worded my sentence "it is possible planet 9 is a primordial black hole"

SI_Rob 7y ago

That, or a spare comet prop accidentally dropped from the Oort catwalk that surrounds our solar-system-scale Truman Show /s

jbattle 7y ago

There was a recent paper that showed it is possible planet 9 is a primordial black hole - would that work? https://phys.org/news/2019-09-planet-primodial-black-hole.html https://phys.org/news/2019-09-planet-primodial-black-hole.ht...

SiempreViernes 7y ago
No, that paper says "What if Planet 9 is a Primordial Black Hole?" and then works out some consequences and finds them to be not ruled out. It doesn't start from observations and arrive at the PBH in any natural way. To judge for yourself hour serious the authors are in proposing a primordial black hole to explain the anomalies in the outer asteroid belt, I refer you to figure 1 in their paper: https://arxiv.org/pdf/1909.11090.pdf https://arxiv.org/pdf/1909.11090.pdf
- red75prime 7y ago
  Would you pass an opportunity to include illustration of an astronomical object at a scale of 1:1?
  - trentlott 7y ago
    I stared at that figure for about a minute and wondered at how friggin' satisfied they have to have been about it. It was and is really neat, even if the likelihood of its reality is low.
- jbattle 7y ago
  Right - that's why I worded my sentence "it is possible planet 9 is a primordial black hole"