system
Given the following post, respond as if you're commenting on Reddit:
human
Does the concept of Altitude exist in space?

Is there an "above" or "below" in space or do all objects exist on the same plane? To be more precise, does the equator of all objects exist on the same plane?

Edit: Thank you for the Gold, wonderful stranger. It's my first.
gpt
No - the equator of Earth is different from the plane of the solar system, which is different from the plane of the galaxy. Galaxies are in amorphous groups or spherical clusters rather than planes. These groups and clusters are in a "cosmic web" filamentary pattern.

We do use latitude/longitude style coordinates for plotting things on the sky, but this isn't a universal system. We either use the Earth's equator as the "plane" for the system (the "celestial" system of "right-ascension" and declination), which is useful for observations from Earth, or we use a galactic system of "galactic latitude" and "galactic longitude", where we define 0° latitude & longitude as the centre of the galaxy, as seen from Earth. So, not only do we use multiple different systems, these systems also only work if you're at (or near) Earth.