The way Earth, the Moon, and the Sun move gives us day & night, the seasons, ocean tides, moon phases, and eclipses.
🌍Spin & Orbit: Day, Night & Year
Rotation = Earth spins on its axis once every 24 hours → day & night.
Revolution = Earth orbits the Sun once a year (~365 days).
Earth's 23.5° tilt aims sunlight more directly at different parts at different times → the seasons.
🌙Phases of the Moon
New
Waxing Crescent
First Quarter
Waxing Gibbous
Full
Waning Gibbous
Last Quarter
Waning Crescent
🔁 The cycle repeats about every 29.5 days — then back to New!
🌑Two Kinds of Eclipse
☀️SOLAR ECLIPSE
The Moon moves between the Sun and Earth and blocks the Sun's light for a while.
☀️ Sun → 🌑 Moon → 🌍 Earth
🌕LUNAR ECLIPSE
Earth moves between the Sun and Moon, so Earth's shadow falls on the full Moon.
☀️ Sun → 🌍 Earth → 🌕 Moon
🌊Why the Ocean Has Tides
The Moon's gravity tugs Earth's oceans, pulling them into a bulge on the side facing the Moon.
A second bulge forms on the far side — so Earth has two high tides at once.
As Earth spins, every coast passes through about 2 high & 2 low tides each day.
🔑Key Terms
🔄RotationEarth spinning on its axis — gives us day & night (24 hours).
🛰️RevolutionEarth's orbit around the Sun — takes about 365 days (one year).
📏Axis & TiltAn imaginary line through the poles, tilted ~23.5° — this causes seasons.
🌊TidesThe rise and fall of ocean water, caused mainly by the Moon's gravity.
🌗Phases of the MoonThe changing shapes we see (new, crescent, quarter, gibbous, full).
🌓Solstice & EquinoxLongest/shortest days (solstice); equal day & night (equinox).
🌑Solar EclipseThe Moon passes between the Sun and Earth, blocking the Sun's light.
🌒Lunar EclipseEarth passes between the Sun and Moon, casting its shadow on the Moon.
⭐Remember: Earth spinning gives us day & night; the Moon orbiting Earth gives us moon phases, tides & eclipses; and Earth's tilt as it circles the Sun gives us the seasons!
✏️ ClickClass Anchor Chart · Earth–Moon–Sun System