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:
× 5 × 5
The corresponding particles of opposite charge to the particles of conventional matter (e.g. the positron is the antiparticle of the electron)
× 5 × 5
× 5
Questions regarding structures designed to aid in the observation of astronomical objects.
× 5 × 5 × 5
× 5
Questions regarding atmospheric conditions on either Earth or on other planets.
× 5 × 5 × 5
Questions regarding Uranus, the 7th planet from Earth's sun.
× 5 × 5 × 4 × 4
× 4
Questions regarding a theoretical 'tunnel' through spacetime which could potentially allow time travel.
× 4
Questions about the apparent displacement of a celestial body with respect to its background when observed along two different lines of sight.
× 4
× 4
Questions regarding the process of accurately finding your location, and getting to another place by planning and following a map.
× 4 × 4 × 4
Questions about the "adulthood" of stars. The main sequence is a distinctive band of stars that appears in a color-magnitude plot (known as Hertzsprung-Russell diagram). Stars appear in the main seque…
× 4
Questions regarding Charon, the largest satellite of the dwarf planet Pluto. Often considered to be Pluto's binary.
× 4 × 4 × 4 × 4
A measure of the ratio of an object's mass with its volume.
× 4 × 4
× 4
Inclination defines the angle between the plane of the orbit of a planet or comet and another plane, usually that of the ecliptic.
× 4
× 4
× 3
about the lack of evidence for alien life, despite the growing evidence that suitable planets are reasonably plentiful.
× 3
Questions about Europa, a moon of Jupiter with a planet-wide ocean under a thick ice crust.
× 3