Or is it just a matter of us not spending the time/effort to find it. I know time on instruments like Hubble is very, very tight and scheduled out years in Advance. But they have been talking about Planet X since like the 80s at least, and probably earlier.
Even Pluto was detectable relatively early and it’s on a crazy orbital plane and elliptical orbit.
It could, the relevant part of the whole thing is the object's mass (and therefore its gravitational influence) and its orbit.
Lex Fridman did a podcast interview a few months ago with Konstantin Batygin [0] about the topic of Planet Nine and he poses this exact question of whether or not it could be a black hole [1].
More specifically, he asks if it could be a primordial black hole which would make it a double discovery since primordial black holes are still only theoretical.
It won't even start to decay until space expands enough that it's warmer than the cosmological background, not that that's more than a rounding error to your calculation.
Counter argument against the black hole hypothesis includes the lack of powerful x-ray activity where the black hole should be. Also, its size would be quite unusual, which in that case could be a primordial black hole, which in itself is theoretical and never been observed.
If it were a black hole, which would necessarily mean a primordial black hole, we would never spot it. We would look, and look, and eventually give up and say it must be a statistical fluke. A coal-black body would also be hard to spot. Surprisingly many asteroids are black, for poorly-understood reasons.
We might not spot it from earth, but if we’re confident enough of where we’ll find it, its orbital parameters, its mass, a probe could be sent, and it could be detected through its SOI, and perhaps even direct observation.
Sure, ~300AU is a long way, but we have the technology, and it’s our closest black hole candidate by many orders of magnitude
If it is a choice between, (1) Spend $500M just to see whether there really is a black hole there, or (2) it is probably a just statistical fluke -- it is not hard to guess which will be chosen.
Comments
Question. Does it have to be a planet out there?
Could it be a small black hole?
Or is it just a matter of us not spending the time/effort to find it. I know time on instruments like Hubble is very, very tight and scheduled out years in Advance. But they have been talking about Planet X since like the 80s at least, and probably earlier.
Even Pluto was detectable relatively early and it’s on a crazy orbital plane and elliptical orbit.
It could, the relevant part of the whole thing is the object's mass (and therefore its gravitational influence) and its orbit.
Lex Fridman did a podcast interview a few months ago with Konstantin Batygin [0] about the topic of Planet Nine and he poses this exact question of whether or not it could be a black hole [1].
More specifically, he asks if it could be a primordial black hole which would make it a double discovery since primordial black holes are still only theoretical.
[0] https://www.youtube.com/watch?v=tm7poMupE8k
[1] https://www.youtube.com/watch?v=tm7poMupE8k&t=4757s
The odds are incredibly tiny for it to be anything other than a planet.
It could be, but it would be the size of a tennis ball. See https://news.ycombinator.com/item?id=28167058
According to my calculations it would take more than 10^53 years to decay.
It won't even start to decay until space expands enough that it's warmer than the cosmological background, not that that's more than a rounding error to your calculation.
Counter argument against the black hole hypothesis includes the lack of powerful x-ray activity where the black hole should be. Also, its size would be quite unusual, which in that case could be a primordial black hole, which in itself is theoretical and never been observed.
If it were a black hole, which would necessarily mean a primordial black hole, we would never spot it. We would look, and look, and eventually give up and say it must be a statistical fluke. A coal-black body would also be hard to spot. Surprisingly many asteroids are black, for poorly-understood reasons.
We might not spot it from earth, but if we’re confident enough of where we’ll find it, its orbital parameters, its mass, a probe could be sent, and it could be detected through its SOI, and perhaps even direct observation.
Sure, ~300AU is a long way, but we have the technology, and it’s our closest black hole candidate by many orders of magnitude
If it is a choice between, (1) Spend $500M just to see whether there really is a black hole there, or (2) it is probably a just statistical fluke -- it is not hard to guess which will be chosen.
Could yes. But it certainly is not the easiest explanation.