archive / atlas record
Mercury
A small, airless world shaped by temperature extremes.
- classification
- Terrestrial planet
- system
- Solar System
Mercury is the innermost planet. Its cratered surface records a long impact history, while a large iron-rich core occupies much of its interior.
- Class
- Terrestrial planet
- Location / system
- Solar System
- Distance
- 0.39 AU mean distance from the Sun
Only values with an established scientific consensus are listed. Where a quantity is uncertain or model-dependent, it is discussed in the sections below rather than stated as data.
Overview (starter entry, expanded review pending)
Mercury is the innermost planet. Its cratered surface records a long impact history, while a large iron-rich core occupies much of its interior.
Imaging, spectra and orbital dynamics
Mercury's surface or atmosphere is constrained by telescopic and spacecraft imaging where available; spectra identify materials, while repeated position measurements establish its orbit and system context.
- What remains least constrained about Mercury?Composition, internal structure, formation history or local environment can require different observations and may remain model-dependent.
Items above are unresolved. Hypotheses are labelled as such and are not presented as confirmed findings.
NASA // verified 28 September 2026
NASA/JPL // verified 28 September 2026