Moon Phases Notes

Co-formation Hypothesis
- Moon formed alongside Earth in the same disk of material.
Capture Hypothesis
- Moon formed elsewhere in the solar system and was captured by Earth's gravity.
Giant Impact Hypothesis
- A large object collided with Earth, causing a piece to break off and form the Moon.
- Explains the differing compositions of Earth and Moon.
- Does not entirely account for the Moon's orbit.
Fission Theory
- Earth spun rapidly to shed a portion of itself, forming the Moon.
- Lack of fossil evidence to support this theory.
- Similar composition of the Moon to Earth's mantle.

The Moon goes through a cycle of appearances known as Moon Phases.
This cycle takes approximately 29 days to complete, which corresponds to the Moon's orbit around Earth (~27 days).

Only half of the Moon can be illuminated by the Sun at any given time.
A location on the Sunlit side experiences daytime; the opposite side experiences nighttime.
Earth’s rotation (once every 24 hours) creates the day/night cycle, impacting visibility of the Moon's phases.

The Moon phases depend on the visible part of the Moon.
- New Moon: Dark side faces Earth.
- Full Moon: Sunlit side faces Earth.

Lunar Eclipse:
- Occurs when Earth’s shadow covers the Moon.
- Visible to anyone on the nighttime side of Earth.

Solar Eclipse:
- Occurs when the Moon’s shadow covers the Sun.
- Visible only to people located in the Moon's shadow.

The Moon orbits Earth at a 5-degree angle relative to Earth’s orbit around the Sun.
Lunar eclipses and solar eclipses happen less frequently than expected due to specific orbital dynamics.
- Typically experience 2-5 solar eclipses per year.
- Lunar eclipses occur 2-4 times each year.