I am not talking about gas clouds, or asteroids really.
Every planet has pretty much the same shape, all that varies is size. Are there any examples of planets or large objects that are clearly not a sphere?
Sure, depending on what you count as being close to a sphere. Some of the larger asteroids and dwarfs have variations up to 5-10% off spherical. And that’s not even getting into the pedantic statement that most astronomical bodies are oblate spheroids.
Both Vesta and Haumea are decidedly non-spherical. Pallas isn’t particularly spherical, either.
Both moons of Mars (Phobos and Deimos) are also not spherical. Likewise, many of the moons of the gas giants aren’t especially spherical.
I should add that Haumea mentioned above is kind of an exception. When you get to that size, gravity is going to naturally make even rocky moons/planetoids more or less spherical.
So, it kind of depends on what you mean by “large”. When you get past the top 20 largest objects in the solar system (which includes all the planets), you do have a fair representation of non-spherical objects.
Depending what you consider large - Neptune’s moon Proteus is a bit of a dog breakfast.
Galaxies.
Belts
Spirals
Rings
Clouds
You forgot dark matter. what shape is dark matter?
Those are all structures, not objects.
But perhaps the most massive missing entry is the black hole: it’s a singularity, not spherical.
All known solar-system objects greater that 200 miles in diameter
2003 EL[sub]61[/sub] (Haumea, 1490km dia) is quite oblate because it spins quickly.
Big, thick, long and hard.
Even many large objectds, e.g. planets, are not spheres but rather are pulled into an oblate spheroid by centrifugal forces (from rotation), tidal forces (from gravity gradients), and local mass anomalies (impact craters, large shield volcano cones, et cetera). The balance between these forces and the gravity field created by a mass concentration (which wants everything to be spherical for symmetry) fsvors the latter when objects get large because of the dominance of gravity over electrostatic and mechanical forces at long ranges, but actually creating a perfect sphere becomes very, very hard.
Stranger
ninja’ed by a stranger
Part of the definition of a planet is that it be [roughly] spherical, so that’s not an accident. At least not since Pluto got kicked out of the club.
A black hole is not a singularity; it contains a singularity. A black hole is spherical if it’s non-rotating, and oblate if it is rotating, like pretty much everything else.
The crust of the Earth is formed of independent grains of dirt. A tree is formed of cells. Water is formed of molecules.
What is an object other than a grouping of bits into a contiguous, bounded form?
Indeed, but galaxies aren’t continuous. Nor are the asteroid belts. Nor the rings around planets. They all have space between them.
Aren’t you thinking of the shape of the event horizon? The black hole itself is a singularity, the event horizon is something else.
As do electrons. And dirt. And all the non-glued parts in a city bus. All objects are mostly space.
The atoms and molecules of planets, trees, and bodies of water also have “space between them”, held together by interacting electromagnetic fields, just as planetary systems, galaxies, and clusters are held together by interacting gravitational fields.
The event horizon of a black hole–the point at which matter, energy, and the information contained within disappear from the universe–is its boundary by definition, and although the treatment under general relativity is a singularity at the convergence of geodesic lines, we really can’t say anything meaningful about what happens beyond the event horizon that can be verified by observation.
Also, although the non-rotating black hole is the most trivial treatment, all real black holes will have some amount of rotational momentum imparted by residual angular velocity of the mass that formed it.
Stranger