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Mike Brown recently wrote a summary of his and Konstantin Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper belt objects (KBOs) whose orbits appe
by tectonic 5y ago
Mike Brown recently wrote a summary of his and Konstantin Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper belt objects (KBOs) whose orbits appear skewed by the invisible gravity of a possible Planet Nine, accounting for observation bias, and running a ton of simulations and MCMC, they concluded: if it exists, Planet Nine has a mass of 6.2 (+2.2/-1.3) Earth masses and a perihelion (closest approach to the Sun) of 300 (+85/-60) AU. The median distance at aphelion is around 500 AU. Those are not small error bars, but they do constrain the search, and this proposed finding of 225±15 AU and a mass of 3-5 ME could just ~barely~ fit.
The summary: https://findplanetnine.blogspot.com/2021/08/the-orbit-of-planet-nine.html https://findplanetnine.blogspot.com/2021/08/the-orbit-of-pla...
We’ve been covering this search in Orbital Index (https://orbitalindex.com https://orbitalindex.com), subscribe if you want updates.
- tectonic 5y agoAlso, Mike Brown's free 'The Science of the Solar System' course on Coursera is excellent. Highly recommended. https://www.coursera.org/learn/solar-system https://www.coursera.org/learn/solar-system
- neunz 5y agoExcellent suggestion!
- zionic 5y agoI’m just mad we’re losing out on “Planet X”. When I was a kid Pluto was a planet so the new one was X (10) and it was cool. Now this new planet is just going to be planet 9 again… totally lame.
- bink 5y agoBut it's from outer space.
- flir 5y agoThe .plan thread is four up from here.
- post-it 5y agoMaybe there's a second one!
- WithinReason 5y agoPlanet 9 II
- depressedpanda 5y agoI think Planet IX has a better ring to it. But I also enjoyed reading the Dune series by Frank Herbert.
- irjustin 5y agoOh man this was me! I 100% agreed until I saw relative size of Pluto[0]. Definitely seems unfair to call it a planet when there's a number of Kuiper belt objects that are larger[1](?) or pretty much the same size. [0] https://www.quora.com/Why-is-Pluto-so-different-from-the-other-planets https://www.quora.com/Why-is-Pluto-so-different-from-the-oth... [1] https://www.universetoday.com/118118/it-looks-like-these-are-all-the-large-kuiper-belt-objects-well-ever-find/ https://www.universetoday.com/118118/it-looks-like-these-are...
- EdwardDiego 5y agoCan't we just add Pluto and Charon together and say "by your ~powers~ masses combined, I am ~Captain~ the ninth Planet!"
- Robotbeat 5y agoPlanetary scientists tend to consider Pluto, and those large Kuiper Belt Objects, to be “planets.” It’s just certain astronomers, who don’t usually study planets, who voted to remove them from planethood. https://www.ucf.edu/news/pluto-planet-research/?amp https://www.ucf.edu/news/pluto-planet-research/?amp Pluto is an impressive planetary system with a bunch of Moons and active geology. I’m gonna call it a planet. Also kind of funny, but this guy who is obsessed with finding “Planet 9” (which doesn’t seem to exist) is also the one who tried and succeeded at demoting Pluto.
- jjk166 5y agoPluto is closer in size to Earth than Earth is to Jupiter, but we lump them both into the same category. There was a real concern that we were going to find thousands of Pluto sized objects in the kuiper belt, and that when we observed them up close they were just going to look like big comets. Instead it turns out there are only a handful and they are fascinating worlds with many similarities to other planets.
- staticautomatic 5y agoPerhaps a dumb question, but if we have some idea of where it was and its probable orbit back then, then why don’t we have some idea of where it is now?
- tectonic 5y agoYes we should.
- spenczar5 5y agoNot at all a dumb question! The argument goes that we haven't had powerful-enough telescopes (or enough dedicated observing time) to image it. Not everyone buys this; some people think it does not exist, and the perturbed orbits of Kuiper Belt objects are just a random fluke.
- svachalek 5y ago"Some idea" is the problem. Basically at the orbit we think it's at, even at the relatively large size they're expecting, it would be a tiny, tiny black dot. It's the proverbial needle in a haystack, knowing which haystack it's in is only the beginning.
- ulzeraj 5y agoI wonder how far would it be from New Horizons.
- saberdancer 5y agoThe scientist that found this potential planet in the old data did calculate the location where the planet should be and provided it in his article. I'm sure there will be follow up studies and some telescopes will be pointing.
- ufo 5y agoAccording to Mike Brown, the infrared sighting from Rowan-Robinson is in a different location in the sky than was predicted by the aforementioned Planet Nine hypothesis. In other words, if this infrared sighting is real it would be a different Planet Nine! https://twitter.com/plutokiller/status/1458038427090178052 https://twitter.com/plutokiller/status/1458038427090178052
- pchristensen 5y agoPlanet 9 3/4?
- labster 5y agoIsn’t that where you board Galaxy Express 999?
- robbedpeter 5y agoHarry Potter and the Conspirator's Planet.
- jagger27 5y agoSo if it turns out that both this object and the hypothesized Planet 9 exist, which one is further out and gets to be Planet X?
- dotancohen 5y agoI really like how that worked out that X would be 10 instead of placeholder_name, and I do hope that at least our grandchildren will see such a discovery.
- Hallucinaut 5y agoLove the newsletter by the way. It's the only one out of dozens I receive that I actually read every time. I can recommend anyone that has an interest in anything space related to give it a read.
- tectonic 5y agoThank you! I’m glad you’re enjoying it.