1.58k likes | 3.5k Views
What Causes Day and Night?. Vocabulary. Rotation =Spinning of the Earth on its axis Revolution =one orbit of an object in space around another object in space; such as the Earth around the sun.
E N D
Vocabulary • Rotation=Spinning of the Earth on its axis • Revolution=one orbit of an object in space around another object in space; such as the Earth around the sun. • Orbit=path an object in space follows as it revolves around another object, such as Earth around the sun or a satellite around Earth.
What causes day and night? • Earth rotating on its axis • It takes 24 hours for Earth to make one complete rotation.
Day Night
Notice that during the changing seasons, some parts of the Earth receive more or less sunlight!
Winter • Spring • Summer • Fall
Daytime for different parts of the world! • Some parts of Alaska can receive 85 straight days of sunlight during the summer months! • Some parts of Alaska are in complete darkness for many days during the winter months.
Because the earth's axis is tilted, the sun's rays strike parts of the earth at different angles at different times of year.
What the Earth looks like in our winter time. • December 21 to March 21 Earth
What Earth looks like during our spring time. • March 21 to June 21 Earth
What Earth looks like in our summer time. • June 21 to September 21 Earth
What Earth looks like during the fall time. • September 21 to December 21
the moon reflects the sun's light, and so its shape changes along with its position relative to the sun and the Earth. What makes the moon appear to change shape?
Moon phase facts to know… • Each phase lasts 2-3 days • A lunar cycle is the time it takes for one phase of the moon (ex. A full moon) to return (ex. To another full moon) • Lunar cycles take approximately 29 days
There are 2 types of eclipses… • Solar eclipse • occurs when the Moon passes between the Sun and the Earth. The Moon fully or partially covers the Sun as viewed from some location on Earth. • Lunar eclipse • occurs when the moon passes behind the earth so that the earth blocks the sun's rays from striking the moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle.
Tides • Rise and fall in sea level with respect to the land • They are not waves!! • There are 2 high and 2 low tides everyday! • produced by the gravitational attraction of the moon and the sun. • Spring and neap
Spring Tides • Occur when the Earth, the Sun, and the Moon are in a line. • New and full moons
Neap Tides • Occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). • Quarter moons