Talk:Orbit

Understanding Orbits Sections

In the Understanding Orbits section I've described a "range of" parabolic and hyperbolic orbits.

Is that accurate?

Or -- from a given firing height, with a given mass -- is there:

• only one possible parabolic orbit and a range of possible hyperbolic orbits, or,
• a range of possible parabolic orbits and only one possible hyperbolic orbit, or,
• only one possible parabolic orbit and one possible hyperbolic orbit?

Note both a parallel firing direction, and the "tilted cannon" discussed in the next Talk subject.

Dubious

I've tagged "The paths of all the star's satellites are elliptical orbits about that barycenter" becaues I think that's a bad approximation of what really happens with respect to the Earth's orbit. Since our orbit is much closer to the Sun that Jupiter is, it would be more accurate to just say the Earth orbits the Sun, rather than the barycenter of the solar system. See the first answer to , which seems like the correct explanation.  — Amakuru (talk) 21:04, 13 September 2020 (UTC)

It may be a bad approximation (I don’t think so), but either way it’s still correct to say that earth orbits the barycenter. Healpa12 (talk) 01:05, 12 March 2021 (UTC)

Mistake in some use of the hat notation?

I've been away from physics for a while so forgive me if I'm completely wrong on this, do let me know, but in the Newtonian analysis of orbital motion section I'm seeing a repeated use of Ô that was confusing me and I realised it's because the article is using this notation for what's quite obviously a non-normalised vector. The hat notation is to represent unit vectors, no? Is this a mistake or am I just misunderstanding something here? CallumMScott (talk) 14:59, 3 September 2024 (UTC)

I agree. Looks like the hat notation is used for unit vectors. Probably ${\hat {\mathbf {O} }}$ should be $\mathbf {O}$ . Let's see if there are any other comments before changing it. Constant314 (talk) 17:31, 3 September 2024 (UTC)

I have never come across this use of the notation, and I don't see any purpose in including the hat. I considered asking the person who put it in the article, in 2014, but he hasn't edited for over two years, so there probably isn't any point in trying to do so. I have removed the hat, but if anyone knows of a good reason for including it then I hope they will explain that reason here. JBW (talk) 09:24, 29 June 2025 (UTC)

Mozilla Orbit

Just FYI: This article here is linked as the "example" article to try article summarizing during onboarding of Mozillas new "Orbit" AI something. So it might get a lot of additional traffic https://orbitbymozilla.com/onboarding --Michael Sch. (talk) 09:23, 31 December 2024 (UTC)

"Orbiter" listed at Redirects for discussion

The redirect Orbiter has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2025 March 17 § Orbiter until a consensus is reached. Jay 💬 17:29, 17 March 2025 (UTC)

Unsourced claim?

The article makes the following unsourced claim:

Newton showed that, for a pair of bodies, the orbits' sizes are in inverse proportion to their masses,

If this were true, then Jupiter should be the closest planet to the Sun. The orbit size is dependent on both the masses and their orbital period, so I'm unclear what it is trying to say. Any ideas? Praemonitus (talk) 17:50, 28 October 2025 (UTC)

For a fixed period, it might be sort of true, but it doesn't seem notable. Just delete it if you want to. Constant314 (talk) 18:39, 28 October 2025 (UTC)

Thanks. I replaced it. Praemonitus (talk) 19:02, 28 October 2025 (UTC)

Spring pendulum?

The 'Newtonian analysis of orbital motion' contained the following paragraph:

When a pendulum or an object attached to a spring swings in an ellipse, the inward acceleration/force is proportional to the distance $A=F/m=-kr.$ Due to the way vectors add, the component of the force in the ${\hat {\mathbf {x} }}$ or in the ${\hat {\mathbf {y} }}$ directions are also proportionate to the respective components of the distances, $r''_{x}=A_{x}=-kr_{x}$. Hence, the entire analysis can be done separately in these dimensions. This results in the harmonic parabolic equations $x=A\cos(t)$ and $y=B\sin(t)$ of the ellipse.

An elastic pendulum has a complex behavior and I'm not quite sure how you get it to swing in an ellipse. It seemed a little off topic for the section, but maybe I'm missing something. Perhaps a spherical pendulum was intended? Praemonitus (talk) 03:28, 1 November 2025 (UTC)

Scaling in gravity

I don't see the benefit of this section. The scaling examples just seem like an application of basic math and don't provide much beneficial insight. Should we keep it? Praemonitus (talk) 15:39, 2 November 2025 (UTC)

First paragraph

Hi everyone,

I recently wrote a rewrite of the first paragraph as I think the paragraph as it stood and stands again is confusingly ambiguous.

For example it introduces revolution and orbit as equal, which is confusing, since a revolution is a part of an orbit.

My main objective though was to better explain that an orbit is a relative motion that is most often described in reference to the main body it orbits (e.g. making it clearer why you can see the Moon orbit Earth and the Sun).

So here is my proposed text, maybe we can find a version that adresses some issues that I see.

"An orbit is the path that an object takes in outer space by being gravitationally bound to an object of mass. The bound object goes around the barycenter of the resulting orbital system, the center of mass with the other object. When the barycenter lies within one of the bound objects, such as within its primary body, the other objects of the system become satellites. If the orbit returns the object, it revolves, completing orbital revolutions, which can change and precess."

For reference the current version: "In celestial mechanics, an orbit is the curved trajectory of an object under the influence of an attracting force. Alternatively, it is known as an orbital revolution, because it is a rotation around an axis external to the moving body. Examples for orbits include the trajectory of a planet around a star, a natural satellite around a planet, or an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion." Nsae Comp (talk) 09:46, 1 March 2026 (UTC)

An object doesn't need to be gravitationally bound for it to follow an orbit. Examples are comets that follow hyperbolic orbits. Thus your proposed rewrite appears fundamentally incorrect, and this is why it was reverted. The final sentence in your proposed rewrite is confusingly written; it also contradicts the first in allowing for open, unbound orbits. The current paragraph is clearer, although I'm not fond of the second sentence. Praemonitus (talk) 14:41, 1 March 2026 (UTC)

Since the article discusses orbit not just as bound orbit the second sentence even more so makes no sense, or is "revolution" also to be understood broader than being a closed orbital path (?). Altogether the broad sense of orbit asks in my opinion for a clarification what orbit is not. It needs to be in space, otherwise atmospheric factors dominate. But is an interstellar travel an orbit? When does it become or ceases to be an orbit? Nsae Comp (talk) 06:48, 15 March 2026 (UTC)

I'm not sure where you draw the line. Stars (like the Sun) and clusters can follow a rosetta orbit through a galaxy; galaxies (and dwarf galaxies) follow orbits through a galactic cluster. Hypervelocity stars can follow escape orbits out of the Milky Way. I'm not sure about "orbital revolution" as the definition varies by source. Praemonitus (talk) 13:57, 15 March 2026 (UTC)