When is part of a planet not a planet?

[ChrisGreaves]

Scientists also found a weird “blip” in Voyager 2 data indicating the spacecraft flew through a plasmoid, a giant magnetic bubble that likely pinched off part of the planet’s atmosphere and floated out into space. Color-corrected images reveal accurate portraits of Uranus and Neptune
Cheers, Chris

[Graeme]

That's a very interesting article, thanks Chris. I knew the Neptunium blue was an enhanced shade to highlight the lighter atmospheric markings but I didn't know about the seasonal colour changes on Uranus.

As for "When is part of a planet not a planet?", perhaps when it's a giant magnetic plasmoid? That's a new one on me too! The Sun does it all the time but I didn't know it was a planetary phenomena as well!

Also, the related article half way down the piece has the wrong image attached:

Screenshot 2024-01-06 080537.png

Do you want to tell them or shall I?

Graeme

[ChrisGreaves]

As for "When is part of a planet not a planet?", perhaps when it's a giant magnetic plasmoid? That's a new one on me too! The Sun does it all the time but I didn't know it was a planetary phenomena as well!

Graeme, thanks for the feedback.
Your point raises a question: "In what way CAN a planet differ from the star which it orbits?"

My understanding is that a star and a planetary system originate from a cloud of gas, and until that cloud differentiates into (1) a star and (2) a set of planetary bodies, it must be a homogeneous mass off gas(es), so it all begins as a set of specific proportions of elements, be they H, He, or Na or Cl.

The star becomes a mass of H/He for sure, but I now suspect that these "giant magnetic plasmoids" must be a feature of many planetary systems. Probability tells us so.

Also, the related article half way down the piece has the wrong image attached: Do you want to tell them or shall I?

You do it; you have extra initials after your name. The best I can come up with is "CPRG" as my name.
Cheers, Chris
P.S. If you do write them, don't lower your self to the level of "don't know your elbow from ..." remarks. C

[Graeme]

Graeme, thanks for the feedback.
Your point raises a question: "In what way CAN a planet differ from the star which it orbits?"

I suppose the answer would be, in as many ways as you can imagine! If Jupiter was several times more massive then it would have been a brown dwarf and our solar system would have been a binary pair of suns, like many others. Some brown dwarfs and red dwarfs have planets that are gas giants. Some stars are so massive they consume all the available gas, live fast, die young and collapse directly into a black hole.

Graeme