Celestial Navigation · Coordinates — Zenith Distance
If a body's observed altitude (Ho) is 30°00', its zenith distance is:
- A90°00'
- B30°00'
- C120°00'
- D60°00'✓ Correct
Explanation
Zenith distance = 90° − Ho = 90° − 30° = 60°. The zenith distance equals the radius (in arc) of the circle of equal altitude centered on the body's geographical position.
Authority: Bowditch (Pub. No. 9), Celestial Coordinates
Practice the full Celestial Navigation bank
Free spaced-repetition quizzing across 2550 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Celestial Navigation questions
- Time
The Nautical Almanac tabulates the positions of celestial bodies against which time standard?
- Time
A vessel in west longitude has a zone description of +5. To convert zone time to UT you must:
- Coordinates
How is the GHA of a star obtained from the Nautical Almanac?
- Coordinates
Sidereal Hour Angle (SHA) is best defined as:
- Coordinates
Declination of a celestial body is the celestial equivalent of:
- The Nautical Almanac
Approximately how fast does the GHA of the Sun increase with time?