system
Given the following post, respond as if you're commenting on Reddit:
human
How do directions work in space?

On Earth we have north, south, east, and west, but those are relative to Earth. What directions, if any, do people use for space?
gpt
There are a few different celestial coordinate systems, which tend to be used in different applications. Astronomers usually use an equatorial coordinate system, which describes the location of objects in the sky using two angles.  Right ascension describes where an object is along the celestial equator (basically longitude), while Declination describes the angle from the equator (basically latitude). The equator is aligned with the Earth's spin axis to make observations simpler.  Ecliptic coordinates work similarly, but align the equator to the plane of the Earth's orbit to work better within our solar system.  There's also a galactic coordinate system, which aligns with the galactic plane and center.
For describing orbits of objects in a solar system, such as asteroids, usually a set of six orbital parameters is used.  These parameters can be used to calculate where an object will appear in the sky at a particular time in an ephemeris table.  For small objects, these parameters have to be updated frequently to account for perturbations by larger planets.