phase of the moon
Let an agent handle Moon phases by name, timing, cause and uses, with computed dates from reliable almanacs.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent handle Moon phases by name, timing, cause and uses, with computed dates from reliable almanacs.
The shape of the Moon illuminated portion as seen from Earth, changing through a cycle of about 29.5 days (the synodic month): new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter and waning crescent.
What it is for: Timekeeping, calendars, observation, tides and cultural observances.
It can be find dates of phases; explain why phases occur; plan observation around moonlight; compute lunar calendar dates.
Distinguishing features
Caused by changing Sun-Earth-Moon geometry
Regular cycle
Not caused by Earth shadow (except eclipses)
Used by lunar calendars
What it looks like
The Moon appearing as a crescent, half, gibbous or full disc.
Physical character
synodic month: about 29.53 days
How it is recognised
Named phases
Waxing versus waning direction
Appearance differs by hemisphere
Related models
is a kind of - category
is a phase of - body
defines - calendar
influences - with the Sun
In practice
Families and kinds
new moon
crescent phases
quarter phases
gibbous phases
full moon
Identifiers
almanac time UTC time of phase ephemerides
Standards and regulation
Astronomical almanacs
Failure modes and hazards
Believing Earth shadow causes phases
Time zone errors for phase dates
Unsupported claims about lunar effects on health
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.phase-of-the-moon
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Phase Which phase.
Phases follow a cycle.
Name
Phase name.
Name
Phase name.
- Which phase is the Moon in now? measurement
- What fraction is illuminated? measurement
Timing
Dates.
Timing
Timing.
- When is the next full or new moon, in which time zone? measurement
- From which almanac? provenance
Cause Why phases occur.
Geometry explains phases.
Geometry
Sun, Earth, Moon.
Geometry
Cause.
- Why do phases occur? definition
- Why is it not Earth shadow? definition
Hemisphere
Orientation.
Hemisphere
Hemisphere differences.
- How does the view differ between hemispheres? definition
- Which way does the crescent face? definition
Uses Calendars and tides.
Phases are used widely.
Calendars
Lunar months.
Calendars
Calendars.
- How do lunar calendars use phases? definition
- Which holidays depend on them? provenance
Tides
Spring and neap.
Tides
Tides.
- How do phases relate to spring and neap tides? definition
- Where are local tide tables? provenance
Observing Moonwatching.
Phases affect observing.
Viewing
Best times.
Viewing
Viewing.
- Which phase is best for viewing lunar features? definition
- When does moonlight hinder stargazing? definition
Claims
Folklore.
Claims
Folklore and claims.
- Is a claimed lunar effect on behaviour or health supported by evidence? provenance
- Which studies? provenance
What the second pass must settle
- Should each phase be a separate entry?
- How should ephemeris sources be linked?
- How should folk names be recorded?