Earth

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Earths Seasons

• What is the reason we have seasons?

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• Earth orbits the sun on a tilted axis. Different
• hemispheres face the sun at different
• times. At any time during the summer or
• winter, one part of the planet is more
• exposed to the sun. This exposure changes
• as Earth spins in its orbit.

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The Earth has 4 seasons in one year!
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What gives us the 4 seasons?

• Earths seasons happen because of the tilt
• of the Earths axis. This tilting is what gives
  us
• the four seasons of the year.
• Spring
• Summer
• Autumn
• Fall

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• The northern and southern hemispheres
• have opposite seasons in the same month.
• It is summer in the hemisphere that is tilted
• towards the sun and winter in the
• hemisphere that is tilted away from the
• sun.

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During the year, we see effects of the axis tilt
on Earth

• The length of the days change
• Summer is warmer than winter

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• Two days of the year have equal periods
• of sunlight and darkness. These days are
• called equinoxes.
• March 20th or 21st
• September 22nd or 23rd

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• Solstices are the days when the sun
• reaches its farthest northern and southern
• declinations.
• Solstices happen twice a year
• December 21st or 22nd
• June 20th or 21st

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Earth orbits the sun on a ____________ axis.

• Straight
• Tilted
• Parallel

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B. Tilted
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What are the four seasons?

1. Spring, Hemisphere, Autumn, Winter
2. Summer, Spring, Winter, Solstice
3. Winter, Autumn, Summer, Spring

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C. Winter, Autumn, Summer, Spring
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There are two days in the year that have equal
periods of sunlight and darkness. These days are
called

1. Hemispheres
2. Solstices
3. Equinoxes
4. Direct days

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C. Equinoxes
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The days when the sun reaches its farthest
northern and southern declinations are called

1. Equinoxes
2. Southern Hemispheres
3. Acute Days
4. Solstices

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D. Solstices