Planet 9?! even less evidence (Introduction)

by David Turell , Tuesday, February 16, 2021, 14:40 (1375 days ago) @ David Turell

A new paper saying it is all a misinterpretation:

https://www.sciencemag.org/news/2021/02/claim-giant-planet-nine-solar-systems-edge-take...

"For planetary scientists, it was the boldest claim in a generation: an unseen extra planet, as much as 10 times the mass of Earth, lurking on the Solar System’s frontier, beyond Neptune. But the claim looks increasingly shaky, after a team of astronomers reported last week that the orbits of a handful of distant lumps of rock are not bunched together by the gravity of “Planet Nine,” as its proponents believe, but only seem clustered because that’s where telescopes happened to be looking.

"Planet Nine supporters aren’t backing down yet but one skeptic not involved with the new work says she is “very happy” to see it. The study has carried out “a more uniform analysis” than done previously of the far-off rocky bodies known as known as Trans-Neptunian Objects (TNOs), says astronomer Samantha Lawler of the University of Regina, who has tried and failed to simulate the clustered orbits in computer models with an extra planet.

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"Napier says the team took account of when and where the telescopes pointed, and how sensitive they were to faint objects. With that data, the team calculated a “selection function” that varies across the sky. And sure enough, the extreme TNOs found by all three surveys were in or near areas where selection function was highest, the team reported on 11 February in a paper posted to the arXiv and accepted by Planetary Science Journal. As a result, Napier says, the team could not reject the null hypothesis that the extreme TNOs are uniformly distributed around the Solar System, which would rob Planet Nine of its foundational evidence. The clustering “is a consequence of where we look and when we look,” he says. “There’s no need for another model to fit the data.”

"Batygin doesn’t accept that conclusion. He points out that the DES survey looked largely in the area of the sky where the TNO cluster he and Brown identified resides and found more extreme TNOs. So ruling out clustering is “not logical,” he says. “The more relevant question to ask is: can their analysis distinguish between a clustered and uniform distribution, and the answer appears to be ‘no',” he says.

"Napier acknowledges that trying to draw conclusions from a sample of 14 TNOs is tricky. “There’s only so much statistical power you can draw with so few objects,” he says. The matter is unlikely to be settled, he adds, until the Vera Rubin Observatory—a powerful new survey telescope being built in Chile—starts observing in 2023. Its survey will have well defined selection biases and is likely to detect hundreds of new extreme TNOs. That, says Napier, “will be like Christmas morning.'”

Comment: Science marches forward with new telescopes and new discoveries. P lanet nine is still a maybe.