 Rotation  The amount of time it takes for Earth to spin around once.  ONE DAY  Revolution  The amount of time it takes for Earth to go around the Sun once.  ONE YEAR

 Perigee  At its closest point in orbit ▪ Object appears large  Apogee  At its farthest point in orbit ▪ Object appears small

 Sun  Provides light, warmth  Source of most of energy that fuels our society  Moon  Raises tides in ocean  Illuminates sky with monthly cycle of phases

 Sun, moon, planets, and stars rise in east and set in west  Caused by Earth’s rotation

 Length of day is a little longer than the time it takes Earth to rotate once on its axis.  As Earth rotates, it also moves in its orbit ▪ It has to turn a little farther  Solar Day  The time period from one sunrise or sunset to the next ▪ Our timekeeping system is based on the solar day

 Length of day and temps may range depending on latitude  What is latitude?  Annual changes are due to Earth’s orbital motion around the Sun  Earth’s orbit is in an ecliptic plane ▪ Oval-shaped

 Does not emit visible light  Reflection of the Sun’s light  Phases of the Moon  The changes of position in the sky is a result of the movement of the moon around the Earth  Lunar Phases ▪ The sequential changes in appearance of the moon  Waxing  Increase in portion of sunlight side of the moon  Waning  Decrease in amount of sunlit side of the Moon

 New Moon  Moon is between Earth and Sun  Dark side of the moon faces Earth  Waxing Crescent  Less than half the lit portion during increase  First Quarter  Half the sunlit side during increase

 Waxing Gibbous  More than half of the lit portion during increase  Full Moon  Earth is between Moon and Sun  Can see entire sunlit side of moon  Waning Gibbous  More than half the lit portion during decrease

 Third Quarter  Half the sunlit side during decrease  Waning Crescent  Less than half the lit portion during decrease  New Moon  Beginning of cycle again

Third

 As the moon orbits, the same side always faces Earth at all times  It spins exactly once each time it orbits Earth  Lunar Month  The length of time it takes for 1 complete cycle of phases ▪ About 29.5 days

 The moon’s gravity pulls on Earth  Creates bulges of ocean water on near and far sides of Earth

 Solar Eclipse  When the Moon passes directly between the Sun and Earth ▪ Moon blocks out view of Sun  Lunar Eclipse  When the Moon passes through Earth’s shadow ▪ Only occurs with there is a full moon