Waning — Science definition
Defined in 2 courses:
- A decrease in the Moon’s observed illuminated fraction over the phase sequence. (Science 6: Matter, Energy & Earth Systems)
- Describes a Moon that is shrinking, getting less lit each night, moving toward new moon. (Earth & Space Science)
Where it is taught
- Moon Phases: Sunlight & Viewing Geometry — Earth, Moon, Sun & Space Models, Science 6: Matter, Energy & Earth Systems, Grade 6
- Earth, Moon & Sun: Moon Phases — Earth, Moon & Solar System, Earth & Space Science, Grade 9
In use
3 days — the Moon runs through eight phases in the same order every single time: new moon → waxing crescent → first quarter (exactly half-lit) → waxing gibbous → full moon → waning gibbous → third quarter (half-lit again) → waning crescent → and back to new.
Earth, Moon & Sun: Moon Phases
Questions using waning
Problem 1
Answer and explanation
Whether the observed illuminated fraction is increasing or decreasing, not a universal left/right rule for every observer.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 2
Answer and explanation
The visible illuminated fraction grows from new toward full and then decreases toward last quarter. About half the Moon remains sunlit throughout; the viewing fraction changes. Eclipses need additional alignment with the tilted orbit, so the full-phase entry does not guarantee Earth’s shadow crosses the Moon.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 3
- A cloudy missing observation proves the Moon has disappeared.
- Every ordinary Moon phase is caused by Earth’s shadow.
- waning: A decrease in the Moon’s observed illuminated fraction over the phase sequence.
- One illustrative result establishes every real condition and needs no further evidence.
Answer and explanation
waning: A decrease in the Moon’s observed illuminated fraction over the phase sequence.
A decrease in the Moon’s observed illuminated fraction over the phase sequence. The visible illuminated fraction grows from new toward full and then decreases toward last quarter. About half the Moon remains sunlit throughout; the viewing fraction changes. Eclipses need additional alignment with the tilted orbit, so the full-phase entry does not guarantee Earth’s shadow crosses the Moon.