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Since the observed composition of the comet is mentioned as being "remarkably" similar to solar system comets isn't there any possibility at all that it could i

Since the observed composition of the comet is mentioned as being "remarkably" similar to solar system comets isn't there any possibility at all that it could indeed be from within our system? Can no combination of freak gravitational nudges/slingshots, however unlikely, result in the observed orbit?

Analemma_ 7y ago
From Wikipedia: "2I/Borisov also has a hyperbolic excess velocity of 32 km/s, much higher than what could be explained by perturbations, which could produce velocities when approaching an infinite distance from the Sun of less than a few km/s"
stouset 7y ago
If the aphelion (furthest point of its orbit) is significantly farther out than the Oort Cloud, then it fundamentally can’t be from anywhere inside our solar system per orbital mechanics. And in this case, its “orbit” is hyperbolic. Meaning it’s going faster than the escape velocity, so will never return. It’s also a dead giveaway if the eccentricity or direction of its orbit are significantly different than those of the rest of the solar system Edit: For objects as far out as the Oort Cloud, a few relatively small changes in velocity can actually result in hyperbolic orbits. The real distinction is a big difference in velocity.
- sandworm101 7y ago
  Unless it interacted with other bodies in the ort cloud. If we consider three-body interactions, slingshots, most any trajectory/orbit might be possible.
  - trentlott 7y ago
    It depends on interobject density and single object mass, I'd reckon. Having it redirect the orbit at velocity might be astronomically (!) low Also, I don't know it's trajectory relative to the solar plane; it might be ruled out by that alone
piannucci 7y ago
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?

Analemma_ 7y ago

From Wikipedia: "2I/Borisov also has a hyperbolic excess velocity of 32 km/s, much higher than what could be explained by perturbations, which could produce velocities when approaching an infinite distance from the Sun of less than a few km/s"

stouset 7y ago

If the aphelion (furthest point of its orbit) is significantly farther out than the Oort Cloud, then it fundamentally can’t be from anywhere inside our solar system per orbital mechanics. And in this case, its “orbit” is hyperbolic. Meaning it’s going faster than the escape velocity, so will never return. It’s also a dead giveaway if the eccentricity or direction of its orbit are significantly different than those of the rest of the solar system Edit: For objects as far out as the Oort Cloud, a few relatively small changes in velocity can actually result in hyperbolic orbits. The real distinction is a big difference in velocity.

sandworm101 7y ago
Unless it interacted with other bodies in the ort cloud. If we consider three-body interactions, slingshots, most any trajectory/orbit might be possible.
- trentlott 7y ago
  It depends on interobject density and single object mass, I'd reckon. Having it redirect the orbit at velocity might be astronomically (!) low Also, I don't know it's trajectory relative to the solar plane; it might be ruled out by that alone

piannucci 7y ago

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?