A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

Type to find tags:
× 119
Questions regarding points of extremely high mass density, which creates an extremely strong gravitational field from which light cannot escape.
× 4
like stars but never achieve nuclear fusion because they are too low-mass.
Questions regarding Callisto, an icy moon of Jupiter.
× 2
× 3
× 7
Questions regarding Charon, the largest satellite of the dwarf planet Pluto. Often considered to be Pluto's binary.
× 4
Questions regarding chthonians, a hypothesised class of exoplanets that are the remnant cores of hot Jupiters.
× 7
Questions regarding grouping objects together based on one or more shared property.
× 5
× 4
track and display the current time.
× 21
Questions regarding the cosmic microwave background, or CMB, the leftover radiation that is taken by many as proof of the Big Bang.
× 5
× 46
Icy bodies that usually consist of methane, water, and other materials that originate from beyond the jovian planets, and occasionally fall into the inner solar system giving off a massive tail as mat…
× 12
Questions about patterns formed by group of prominent stars in the night sky.
× 21
Questions on systems to uniquely determine position of a point or other geometric element on a manifold such as Euclidean space.
× 12
Questions regarding the material at or near the center of an astronomical object.
× 4 × 4
× 9 × 30
Questions regarding the phenomenon in the early universe characterized by an extreme expansion of space.
× 82
Questions about the origin, history, evolution and fate of the Universe.
× 21
Questions regarding the as-yet-unknown energy permeating the universe that is responsible for its expansion.
× 34
Questions about the source or effects of the matter that makes up 85% of the matter in the universe but appears to only interact gravitationally.
× 25
a process of inspecting, cleaning, transforming, and modeling data with the goal of discovering useful information, suggesting conclusions, and supporting decision making.
× 18 × 8 × 11 × 6
A measure of the ratio of an object's mass with its volume.