Dictionary term
Great Circle
Direct answer
Great Circle: A Great Circle is the intersection of a sphere with a plane passing through the sphere’s center.
It is the largest possible circle on a sphere.
- Source
- The Great Almanac Dictionary
- Category
- Astronomy & Skywatching
- Also appears in
- Astronomy & Skywatching
- Aliases
- None listed
- Last updated
- 2026-07-16
Quick reference
- Use when
- Use spherical rather than flat-map geometry for wide sky separations.
- Do not use it for
- A straight line on a chart projection may not represent a great-circle arc.
- Reference category
- Astronomy & Skywatching
- Related terms
- Astronomical Nadir, Prime Vertical, Small Circle, Celestial Horizon
The story behind Great Circle
Great circles have been foundational in astronomy, geography, and navigation.
Great Circle in spiritual tradition
The simplest spherical path often looks curved on paper.
The Great Almanac frames Great Circle with educational restraint. Mystical or symbolic language may be meaningful, but it should not be exaggerated into certainty, panic, or permission to ignore ordinary responsibility.
Great Circle in the Bible
This is a factual astronomy reference. It can support wonder at the created order without becoming a claim of fate, worship, or private revelation.
Great Circle in numerology
Great Circle is not a numerology claim. Any numbers attached to it should retain their ordinary scientific, calendrical, navigational, or historical meaning unless a separate symbolic interpretation is clearly labeled.
Why Great Circle matters
Great-circle arcs define angular separation and shortest routes on spherical models.
Example in a reading: The celestial equator and every hour circle are great circles.
Interpretive caution: A straight line on a chart projection may not represent a great-circle arc.
How Great Circle is used in a reading
Use spherical rather than flat-map geometry for wide sky separations.
Where interpretation stops
Great Circle is presented as sourced astronomy, calendrical, Earth-science, cultural, or instrument-history reference. Definitions should distinguish measured phenomena from civil convention and historical interpretation, preserve location and time dependencies, and avoid turning factual sky data into a deterministic personal claim.
Sources and editorial method
Research references used for this entry include:
- U.S. Naval Observatory: Astronomical Almanac Glossary - Definitions for astronomical coordinates, time, reference systems, and observable phenomena.
- International Astronomical Union: Standards of Fundamental Astronomy - IAU-maintained standards and algorithms for astronomical reference systems and coordinate transformations.
The page starts with a direct definition, then separates use, example, caution, spiritual meaning, and historical context. For astrology, occult, demonology, curse, and spiritual warfare terms, the editorial rule is to explain the term without making fear-based, fatalistic, medical, legal, financial, or ritual-instruction claims.
Continue learning
Continue from the definition into current sky positions, space weather, and the live collective celestial view.
Open Worldwide WatchRelated terms
These related entries help place Great Circle inside a wider reference cluster instead of leaving it as a standalone keyword.
