Skip to main content
20 votes
Accepted

Can the paper narrowing Solar System's barycentre to within 100m help find Planet Nine?

Short answer Short answer is no, it can't prove or disprove the existence of Planet 9. Even if there is a significant difference between the barycenter of the solar system with and without Planet 9 ...
William Miller's user avatar
17 votes
Accepted

Could the 9th planet be virtual?

The ninth planet can absolutely be a "virtual", in the way you describe it, meaning observed data indicating the gravitational influence by an object is not actually caused by such an object. A ...
SE - stop firing the good guys's user avatar
8 votes

Why hasn't the "9th Planet" been detected already?

Adding to the other excellent answers here, if there were an unobserved "Planet 9" the possibility of it being a difficult to observe primordial black hole has been raised. According to Phys....
uhoh's user avatar
  • 30.6k
8 votes
Accepted

If "9 th planet" is ejected by Jupiter or Saturn, why does it have a very far perihelion?

This is certainly a problem for any hypothesis that form planet 9 by ejecting it from the inner solar system. The issue (for those wondering) is that if you simply scatter an object out of the inner ...
ProfRob's user avatar
  • 155k
8 votes
Accepted

Is Planet Nine shepherding the Kuiper Belt?

Estimates of Planet 9's orbit currently suggest that it doesn't have any major effect on the Kuiper Belt, because its orbit is too far away and on a different plane than the Kuiper belt, and from the ...
bandybabboon's user avatar
  • 4,250
8 votes
Accepted

How does 2015 RR245 compare to the other KBOs predicting "Planet 9"?

It was the first thing I thought too, but I would say it won't count in the statistics. The earlier paper by Batygin & Brown was talking about bodies orbiting further out. 2015 RR245 orbits ...
Andy's user avatar
  • 2,467
8 votes
Accepted

Is Planet Nine observable in principle?

If they knew exactly where to point Mr. Hubble, then yes, it should be easily visible, though at that distance, it would still be blurry, not a clean image. The estimated apparent magnitude of Planet ...
userLTK's user avatar
  • 24.1k
7 votes
Accepted

If thousands of exoplanets have been discovered, why haven't we discovered planet 9 yet?

There are two primary reasons Planet Nine (if it exists) is extremely hard to detect: it's very dim and its position is not well constrained. Brightness - We are able to see planets in our solar ...
Phiteros's user avatar
  • 3,166
6 votes
Accepted

If Planet Nine indeed exists, how large a impact event there should be to be seen from Earth?

We can compare the brightness of a comet hitting planet 9 with the 1994 impact of Shoemaker-Levy 9 / SL9 on Jupiter. It was seen by Hubble, and Galileo which was orbiting Jupiter at the time. View ...
bandybabboon's user avatar
  • 4,250
6 votes
Accepted

Why does Wikipedia state that the Solar System has one unconfirmed planet?

That was a rather recent (16 January 2021) change to that wiki page made by a user named Mariofeds, who does not have a wikipedia user page and who has just one contribution to wikipedia. It may well ...
David Hammen's user avatar
  • 34.1k
4 votes

How can we map masses orbiting the outer Solar System by determining the orbits of planets and smaller objects?

Iorio (Preliminary constraints on the location of Telisto/Planet Nine from planetary orbital dynamics) has suggested transmissions from the New Horizons probe (currently beyond Pluto) could be used to ...
Andy's user avatar
  • 2,467
4 votes

Could the 9th planet be virtual?

That's an interesting way to put it. Indeed, since bodies spend most of their time at the slow end of an eccentric orbit, the extended lobes will attract each other, torquing the orbits into a ...
JDługosz's user avatar
  • 1,000
3 votes

Is there any legitimacy to this report of planet nine being discovered by an amateur?

This has not been confirmed so whether it is legit is unknown at this time. A recent report (https://arxiv.org/abs/1706.05348) calls into question the original analysis that leads to the initial ...
Natsfan's user avatar
  • 4,494
2 votes

What good evidence exists for the 9th planet as spoken of by Caltech?

If (and it's a big if) your sample is unbiased, that is, random, and if the population sampled is large, then the percentage sampled is completely irrelevant - only the absolute number of samples ...
Kristoffer Sjöö's user avatar
2 votes

What are the 4 candidates for Planet Nine reported in 2017?

A frequently cited study about Planet Nine is arXiv:1601.05438: Evidence for a Distant Giant Planet in the Solar System, but I can confirm that after 2016 there are not too many studies on the subject,...
B--rian's user avatar
  • 5,626
1 vote
Accepted

Is there or will there be any search after a primordial black hole 500 au from the Sun?

Maybe, Harvard scientists have proposed a way to determine, once and for all, whether Planet Nine actually could be a black hole. Specifically, the new method would scour the outer solar system for ...
Natsfan's user avatar
  • 4,494

Only top scored, non community-wiki answers of a minimum length are eligible