Earth Moon Sun System How does the Earth Move? What causes seasons? Why does the moon appear to change shape?

How does the Earth Move? The Earth Moves in space in to major ways: Rotation and Revolution Rotation is the spinning of an object on its axis Revolution is the movement of one body around another body

Revolution of Earth The Earth is tilted on its axis about 23 degrees This tilt is why the Earth has seasons as it revolves around the sun

Remember the direct and indirect sunlight from last unit There are parts of the year that the north and south poles never get sunlight During the winter, we have shorter days, and our place on Earth spends more time in the dark, away from the sun During the summer, our days are longer, we spend more of the 24 hours of the day, on the lit side of the Earth.

Summer and Winter Solstice The longest and shortest days of the year are called solstices The winter solstice is in December and the summer solstice is in June

Motions of the Moon The changing relative positions of the Sun, Earth, and moon cause the phases of the moon. The Sun is always shining on half of the moon, just like Earth. We do not see the entire lit portion each night Sometimes the moon is highest in the sky during the day!

Eclipses A solar eclipse happens when the moon passes between the Earth and the sun, blocking the sun A lunar eclipse happens when the Earth passes between the sun and the moon Why do we rarely see a lunar eclipse? Why do we rarely see a solar eclipse? Umbra – the very darkest part of the shadow during an eclipse Penumbra – a larger part of the shadow that doesn’t block the light entirely