New Moon Geometry
Lesson notes
Overview
At new moon the Moon sits between Earth and Sun, showing us its dark side. This topic is rated beginner and is number 57 of 98 in Earth & Space. Core ideas and first intuitions. No prior knowledge needed.
What you are seeing
The panel above shows an interactive animation of the idea. Every slider changes one quantity so you can see its effect on the outcome. The animation is drawn live from the model, so everything you see responds to the sliders. Press Space to pause, use Restart to replay from the start, and change the speed to slow down quick events.
In depth
At new moon, the Moon lies between the Earth and the Sun, at an angle of 0° from the Sun, so its sunlit side faces away from us and we see the dark side, if anything. It rises and sets with the Sun and is not visible in the sky. If the alignment is exact, the Moon’s shadow falls on the Earth and a solar eclipse occurs, but because of the orbit’s tilt, this happens only a couple of times a year.
Reading the relationship
The expression "0°" is a compact summary of the idea. Then use the sliders to see how changing one quantity changes the others.
A guided exploration
1. Run the animation once with the default settings and describe in words what happens. 2. Change one slider at a time and note which quantity responds most. 3. Push each slider to its extreme and decide whether the result still makes sense.
Try this
Start by only moving one slider at a time. Say aloud what you expect, then check.
Common pitfalls
Earth and space systems work on very different scales of time and distance. Check which scale a number refers to before comparing it with another.
How it connects
It builds on “Full Moon Geometry”, the topic before it in Earth & Space. Once you are comfortable, continue with “Earthquake Magnitude and Energy”.
Why it matters
Earth and space science helps us understand our planet, its climate and the wider universe.
Where you might use it
- Revising “New Moon Geometry” before a class, exam or certification
- Forecasting weather and understanding climate records and their uncertainty
- Planning for earthquakes, floods and other natural hazards in cities
- Interpreting satellite images, space missions and the age of rocks and stars
Frequently asked questions
What is New Moon Geometry?
At new moon the Moon sits between Earth and Sun, showing us its dark side. It is a beginner topic in Earth & Space.
How do I use the New Moon Geometry simulation?
The panel at the top shows an interactive animation of the idea. Every slider changes one quantity so you can see its effect on the outcome. Move the sliders one at a time, then press Space to pause the animation and look closer.
What does the formula mean?
The expression 0° packs the idea into symbols. Name each symbol first, then change one quantity with the sliders and see which others respond.
Who is this topic for?
Core ideas and first intuitions. No prior knowledge needed. If the quiz feels hard, reread the lesson notes and try the previous topic first.
What should I learn before this?
Start with “Full Moon Geometry”, the previous topic in Earth & Space. Each topic in a subject builds on the ones before it.
How do I track my progress?
Press “Mark as learned” on this page. Progress is stored only in this browser and is never sent anywhere. The Browse page can show topics you have learned or still need to learn.