An Anonymous Coward writes:
It's not just Saturn and gas giants such as Uranus which have rings in our solar system – as a tiny dwarf planet has just been spotted with its very own.It's the first dwarf planet beyond Neptune to be spotted with its own ring – and could prove that such rings are not uncommon in the outer solar system.
It's not just Saturn and gas giants such as Uranus which have rings in our solar system – as a tiny dwarf planet has just been spotted with its very own.
It's the first dwarf planet beyond Neptune to be spotted with its own ring – and could prove that such rings are not uncommon in the outer solar system.
takyon: Haumea has two known moons as well as this newly discovered ring:
A stellar occultation observed on 21 January 2017 indicated the possibility of a ring system around Haumea. As published in Nature on 11 October 2017, this occultation was confirmed to be a ring, representing the first such ring discovered for a TNO. The ring has a radius of about 2,287 km, a width of ~70 km and an opacity of 0.5. The ring plane coincides with Haumea's equator and the orbit of its larger, outer moon Hi'iaka. The ring is close to the 3:1 resonance with Haumea's rotation.
Haumea is known for its extremely elongated shape, a consequence of its rapid rotation.
The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation (DOI: 10.1038/nature24051)
Cool, dwarf planets can have moons and rings. If it quacks like a duck... well, you know. This quacks like certain large planets in a solar system.
Maybe a simple semantics trick? Call them all planets, and add a modifier to the big ones, instead of the little ones. Call the big ones "major planets", "super planets", "power planets", or ... well, something.
Knowing astronomers, it would be "Large Planet, Very Large Planet, Extremely Large planet, 30m planet and Overwhelmingly Large Planet [cancelled]"
How about they just make it simple, anything that forms a spherical shape due to it's own gravity is a planet. Yes you can exempt stars and derivatives there-of, but you really don't have to. I know I'm asking for too much, these are the same type of people that call the same thing three different things depending on where it actually is.
I like the current definition that says it has to dominate its orbit and clear out any stuff there.
The International Astronomical Union also specifies that a planet must orbit around only one object (a star).
.I also like the word planetoid for lesser objects.
.it's own gravity
it's == it is; it hasits == belongs to itA pronoun never needs an apostrophe to make it plural. (its, ours, yours, hers, theirs)
-- OriginalOwner_ [soylentnews.org]
> I like the current definition that says it has to dominate its orbit and clear out any stuff there.
Almost all major planets have moons and trojans. I don't know why they have a definition that needs extra clarification.
Is it over 90% round, bigger than a breadbox, orbiting a star with an excentricity below 90%, and any objects orbiting it don't bring that system's center of mass outside of the body? It's a planet.KISS.
Actually, not "a star", but "the Sun". So yes, by definition there are only eight planets in the entire universe.
"Centaurs [wikipedia.org]" can also have rings