Σ σ Sigma is a letter in the Greek language alphabet of Earth, originating in the early period of Human history. It is used for designations in science, mapping and other fields used in space travel and communications. Many planets, planetoids, stars and star systems use a variation of this term in their name.
|Α α - Β β - Γ γ - Δ δ - Ε ε - Ζ ζ - Η η - Θ θ - Ι ι - Κ κ - Λ λ - Μ μ - Ν ν - Ξ ξ - Ο ο - Π π - Ρ ρ - Σ σ - Τ τ - Υ υ - Φ φ - Χ χ - Ψ ψ - Ω ω|
Sigma could also refer to:
- planets and moons
- space stations and outposts
- stars and star systems
- wars and military engagemants