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Race to discover Planet Nine using astronomy and new computational techniques

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Re: Race to discover Planet Nine using astronomy and new computational techniques

#31
post #8

What do you define as a planet though? If you consider our sun a frame of reference, you might find that technically some far away objects bigger than the sun have complex periodical movements around the sun.

I think that's an interesting question, but the search being described is for a fairly specific kind of object with constrained parameters: https://en.wikipedia.org/wiki/Planet_Nine

Re: Race to discover Planet Nine using astronomy and new computational techniques

#32
post #5

Earlier quoted context omitted.

My intuition suggests that a planet far out and small would be very difficult to detect by its occlusion. This page calculates that Pluto for instance spans only 3 pixels at the Hubble space telescopes resolution: http://www.planetary.org/blogs/emily-lakdawalla/2013/0214101...

If Hubble can barely see Pluto, how the heck did terrestrial telescopes find it in the first place?

Wasn't the presence of a Pluto-like body _known_ because the orbits of other planets didn't match expectations based on the gravitational pulls of all the other known bodies in our solar system?

Re: Race to discover Planet Nine using astronomy and new computational techniques

#33
post #5

Earlier quoted context omitted.

My intuition suggests that a planet far out and small would be very difficult to detect by its occlusion. This page calculates that Pluto for instance spans only 3 pixels at the Hubble space telescopes resolution: http://www.planetary.org/blogs/emily-lakdawalla/2013/0214101...

If Hubble can barely see Pluto, how the heck did terrestrial telescopes find it in the first place?

To see something that acts like a point of light, size doesn't matter at all. Glowing objects are visible even when their area is a small fraction of a pixel. But your chances of noticing occlusion are much lower.

Re: Race to discover Planet Nine using astronomy and new computational techniques

#34
post #28

New And Better Data Disfavors A Giant World Beyond Neptune https://www.forbes.com/sites/startswithabang/2017/06/21/good... As the months passed since it was first proposed by Konstantin Batygin and Mike Brown, they compiled additional evidence for it, and things were looking rosy. But a new study by Shankman et al. has turned the evidence on its head, disfavoring the planet's existence and uncovering a bias in the da…

Yes, I've heard of that. Some follow-up articles I've read [1] [2] say that the evidence against (or for) Planet Nine is still inconclusive. But the question should be settled one way or another: Planet Nine will either be there or it won't.

[1] "Solar System survey casts doubt on mysterious 'Planet Nine'" [ https://www.nature.com/news/solar-system-survey-casts-doubt-... ]

[2] "Planet Nine Is Put on Trial in Absentia" [ https://www.quantamagazine.org/planet-nine-is-put-on-trial-i... ]

Re: Race to discover Planet Nine using astronomy and new computational techniques

#35

Earlier quoted context omitted.

If Hubble can barely see Pluto, how the heck did terrestrial telescopes find it in the first place?

Wasn't the presence of a Pluto-like body _known_ because the orbits of other planets didn't match expectations based on the gravitational pulls of all the other known bodies in our solar system?

Not exactly. It's true that Neptune was discovered that way and that people found Pluto while looking for a "Planet X" that would explain other gravitational discrepancies:

In the 1840s, Urbain Le Verrier used Newtonian mechanics to predict the position of the then-undiscovered planet Neptune after analyzing perturbations in the orbit of Uranus. Subsequent observations of Neptune in the late 19th century led astronomers to speculate that Uranus's orbit was being disturbed by another planet besides Neptune.[1]

However it turned out that Pluto was not Planet X after all. After all Neptune and Uranus are respectively about 7900 and 6700 times more massive than Pluto.

In 1978, the discovery of Pluto's moon Charon allowed the measurement of Pluto's mass for the first time: roughly 0.2% that of Earth, and far too small to account for the discrepancies in the orbit of Uranus. Subsequent searches for an alternative Planet X, notably by Robert Sutton Harrington, failed. In 1992, Myles Standish used data from Voyager 2's flyby of Neptune in 1989, which had revised the estimates of Neptune's mass downward by 0.5%—an amount comparable to the mass of Mars—to recalculate its gravitational effect on Uranus. With the new figures added in, the discrepancies, and with them the need for a Planet X, vanished. Today, the majority of scientists agree that Planet X, as Lowell defined it, does not exist. Lowell had made a prediction of Planet X's orbit and position in 1915 that was fairly close to Pluto's actual orbit and its position at that time; Ernest W. Brown concluded soon after Pluto's discovery that this was a coincidence, a view still held today.[2]

[1] https://en.wikipedia.org/wiki/Pluto#Discovery [2] https://en.wikipedia.org/wiki/Pluto#Planet_X_disproved

Re: Race to discover Planet Nine using astronomy and new computational techniques

#36
post #28

New And Better Data Disfavors A Giant World Beyond Neptune https://www.forbes.com/sites/startswithabang/2017/06/21/good... As the months passed since it was first proposed by Konstantin Batygin and Mike Brown, they compiled additional evidence for it, and things were looking rosy. But a new study by Shankman et al. has turned the evidence on its head, disfavoring the planet's existence and uncovering a bias in the da…

The article accounts for this new data. You might want to see Batygin's post itself here: http://www.findplanetnine.com/2017/06/status-update-part-1.h...

Basically, yes, if you just look at bodies that OSSOS detected, it does not support the Planet Nine hypothesis. If however you consider both what OSSOS found and the already known TNOs, the new picture reinforces the Planet Nine hypothesis (with one outlier TNO that doesn't really fit, although it can apparently be made to).

Re: Race to discover Planet Nine using astronomy and new computational techniques

#37
post #28

New And Better Data Disfavors A Giant World Beyond Neptune https://www.forbes.com/sites/startswithabang/2017/06/21/good... As the months passed since it was first proposed by Konstantin Batygin and Mike Brown, they compiled additional evidence for it, and things were looking rosy. But a new study by Shankman et al. has turned the evidence on its head, disfavoring the planet's existence and uncovering a bias in the da…

And from Batygin and Brown's (font-mangled) website: "A recent paper[1] that Mike put together shows exactly the opposite to be true for the non-OSSOS dataset: observational bias cannot account for orbital clustering beyond 250AU."

I love this sort of debate.

[1] https://arxiv.org/pdf/1706.04175.pdf

Re: Race to discover Planet Nine using astronomy and new computational techniques

#39
post #19

Earlier quoted context omitted.

I vote for either Yuggoth or Nibiru.

Nibiru is usually referred to as "Planet X". If it was called "Planet IX", it would be a better fit. :-)

IX would be a slightly ominous name to choose :) https://en.wikipedia.org/wiki/Ix_(Dune)
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