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A 1980s space telescope may have seen planet nine

gizmodo.com

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Re: A 1980s space telescope may have seen planet nine

#121

Post by hnbad »

SkittyDog wrote: post #68
odyssey7 wrote: post #63

Earlier quoted context omitted.

At risk of maybe going too far on a tangent, I understand this idea and the species example is a good one. The planets are different because they were first defined as mystical and cultural concepts, before they could be understood as scientific ones. There are plenty of people who still think about the planets as cultural concepts rather than scientific ones. (What is a Jupiter? It’s a thing in space that our cultur…

I'm pretty sure animal and plant species also existed as cultural and mystical concepts, long before science was a thing. All of your analysis can be applied equally well to species, as well as planets... Or the four seasons (winter, spring, summer, autumn) or the five Oceans, or the seven Continents. They're all simply human attempts to impose neat category boundaries across a continuum of natural phenomena that are…

I think this boils down to journalists trying to bait outrage by implying that scientific definitions should dictate cultural ones (tomato may be a fruit biologically speaking but if you put it in a fruit salad nobody will like you).

Pluto is a "planet" in the same way the sun is "not a star". If you tell someone to draw some stars you'll be confused if they just draw a few massive orbs of fire rather than some bright dots.

Before publishers discovered outrage bait as a way to sell ads, "actually Pluto is a dwarf planet not a planet" would have been an irrelevant nerdy factoid but now it's presented as a cultural issue everyone needs to have an opinion on.

So I propose just giving scientists migraines instead and discussing whether the sun and moon should be considered planets or stars.

Re: A 1980s space telescope may have seen planet nine

#122

Post by dotancohen »

jagger27 wrote: post #61
ufo wrote: post #56

Earlier quoted context omitted.

According 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

So 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?

I 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.

Re: A 1980s space telescope may have seen planet nine

#123

Post by dotancohen »

cosmojg wrote: post #103

I really hope it's a bowling-ball-sized black hole so we can start slingshotting rockets off into deep space.

  Radius of bowling ball: 12 cm [1]  
  Mass of black hole with radius 10cm: 0.00004062 Sun Mass [2]  
  0.00004062 Sun Mass in kilograms: 8.124E+25 [3]
That's significantly more than 10 times the mass of the Earth. Even a grape-sized black hole would be more massive than Earth. Highly unlikely to be such a massive object, hithertofore undetected. The most massive object expected would be smaller than the Moon, which for a black hole would be the size of a human ovum.

  [1] https://hypertextbook.com/facts/2009/MarwaElfar.shtml
  [2] https://www.omnicalculator.com/physics/schwarzschild-radius
  [3] https://www.unitconverters.net/weight-and-mass/sun-s-mass-to-kilogram.htm

Re: A 1980s space telescope may have seen planet nine

#124

Post by saberdancer »

staticautomatic wrote: post #50
tectonic wrote: post #3

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…

Perhaps 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?

The 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.

Re: A 1980s space telescope may have seen planet nine

#126

Post by ulzeraj »

depressedpanda wrote: post #81
zionic wrote: post #64

Earlier quoted context omitted.

I’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.

I think Planet IX has a better ring to it. But I also enjoyed reading the Dune series by Frank Herbert.

Uncle Malky deserved better.

Re: A 1980s space telescope may have seen planet nine

#127

Post by ulzeraj »

svachalek wrote: post #77
staticautomatic wrote: post #50

Earlier quoted context omitted.

Perhaps 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?

"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.

I wonder how far would it be from New Horizons.

Re: A 1980s space telescope may have seen planet nine

#128

Post by raxxorrax »

widforss wrote: post #117
netcraft wrote: post #91

Earlier quoted context omitted.

There are two main ways we detect exoplanets. The primary way that I believe accounts for the vast majority of planets we have detected is the transit method. Basically we watch the light from a star very closely and look for a dip in the amount of light coming from it as a planet transits in between us and the star. This of course depends on the planet to pass directly between us and the star, and that means that it…

If that is the threshold for discovering exoplanets, haven't we already found Planet Nine since we definetly have detected the planet's effects?

Good objection actually. We could say that we found exoplanets visually, can determine its mass and size and therefore its density and make careful prediction about its characteristics from that, which is probably nothing more than an educated guess.

Here we just found its gravitational effect.

Re: A 1980s space telescope may have seen planet nine

#129

Post by SkittyDog »

hnbad wrote: post #120
SkittyDog wrote: post #59

Earlier quoted context omitted.

I hate to be the one to break the bad news to you, but... That's pretty much how all science works. https://en.m.wikipedia.org/wiki/Species_concept Categorization is a leaky abstraction. Use them when they're useful, and ignore them when they become more trouble than they're worth.

This is an example I also find helpful when dealing with people who insist that "there are only two genders" ("because science"). Even species is a leaky abstraction, let alone sex, gender and sexual attraction. You can argue for a strict gender binary normatively (and we can disagree on that), but even if you try to conflate gender and sex it's still scientifically illiterate to insist that there is a strict binary…

You make the point beautifully, and I really appreciate how you bring home the consequences of flawed thinking in our politics.
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