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Comment by hparadiz | original | For first time, a cell built from scratch grows and divides
[−]hparadiz · 2026-07-01 Wed 17:12 UTC · link
> Exoplanets also aren't planets.

Imagine writing this.

[−]Aerolfos · 2026-07-01 Wed 17:48 UTC · link
Actually, that is the IAU stance. And their definition for exoplanet includes small, non-rounded objects orbiting stars which would be asteroids (or comets or whatever) if they happened to be around the Sun.

All that debacle around dwarf planets to prepare for future observations, and yet the distinction ceases to apply the moment you go outside the Oort cloud...

But really, that's just the naming systems being bad, obviously common people don't think asteroids around other stars are "exoplanets" or should be called that way

[−]hparadiz · 2026-07-01 Wed 17:52 UTC · link
I'm not talking about edge cases like asteroids or planetoids or dwarf planets. I'm talking about actual planets. Like a gas giant orbiting a star. It's obviously a planet even if it's not orbiting Sol.
[−]ben_w · 2026-07-01 Wed 18:53 UTC · link
It's perfectly coherent to argue that gas giants should count failed stars rather than as planets, given the boundary between them is under debate.

https://en.wikipedia.org/wiki/WISE_0855%E2%88%920714

[−]jibal · 2026-07-01 Wed 20:33 UTC · link
It's perfectly irrelevant to the thread.
[−]ben_w · 2026-07-02 Thu 05:24 UTC · link
This thread is ~

  "Exoplanets also aren't planets": discuss
As the easiest to discover exoplanets (and all the early ones except pulsar planets) are gas giants, and the comment I was directly replying to had "Like a gas giant orbiting a star. It's obviously a planet", therefore "gas giants are failed stars and shouldn't count as planets" is not at all irrelevant.

Even further up to the point of if these are or are not cell, it illustrates how taxonomical categories are made by humans for humans. Historically, any connection to natural laws in taxonomies is often mere coincidence.

[−]jibal · 2026-07-01 Wed 23:45 UTC · link
This is quite wrong.

https://www.iau.org/IAU/Science/What-we-do/Pluto-and-the-Dev...

"More generally, a planet:

a. orbits its host star, just as the Earth and Jupiter orbit the Sun,

b. is large enough to be mostly round, and

c. must have an important influence on the orbital stability of the other objects in its neighbourhood."

Exoplanets are planets by that definition where the host star is not our Sun:

"Researchers have found hundreds of extrasolar planets, or exoplanets, that reside outside our solar system. "

[−]LeifCarrotson · 2026-07-01 Wed 18:02 UTC · link
What they meant when they said "planets" was the 8 (previously 9, previously to that 8, previously 7...) known and named planets in our own solar system. A hypothetical "Journal of Planets" that was actually about solar system astronomy wouldn't necessarily have known what to do with a new paper about 51 Pegasi b published 30 years ago. They're thinking "when we said planets, we actually always meant solar system planets, it just never came up until now".

The reviewer of this paper is saying that by biology they always meant naturally evolved cellular biology, not synthetic biology - there's just never been an example of the latter before.

I think the take is wrong, the receiving journals should be excited to expand their scope rather than frustratedly redefine their scope more narrowly, but definitions and categorization are hard.

[−]jibal · 2026-07-01 Wed 20:32 UTC · link
> What they meant when they said "planets"

Who is "they", and how do you know what they meant?

The relevant fact is that the claim "Exoplanets also aren't planets" is simply wrong -- exoplanets are by definition planets outside the solar system. It's like claiming that a brown furple isn't a furple -- the claim is wrong, regardless of what one thinks a furple is.

> The reviewer of this paper is saying that by biology they always meant naturally evolved cellular biology, not synthetic biology - there's just never been an example of the latter before.

They aren't saying that, and that isn't true.

[−]antonvs · 2026-07-01 Wed 21:35 UTC · link
The argument you describe is as if Neil deGrasse Tyson took a course about “How to be even more extremely and inappropriately pedantic,” and decided he wanted to become the undisputed world expert at that.

Anyone who says “exoplanets aren’t planets” really needs to think a little harder about the actual meaning of what they’re saying.