SEASONSby: Jimnaira U. Abanto

Earth moves in TWO WAYS

1. ROTATION-- The spinning of Earth on its axis.

Axis-the imaginary line that goes through the center of the Earth.

“EARTH ROTATES AROUND ITS AXIS ONCE A DAY.”

2. REVOLUTION---is the movement of the Earth its orbit.

ORBITThe path that an object follows as it revolves around another object.

“EARTH REVOLVES AROUND THE SUN ONCE A YEAR.”

Why do we have seasons? The seasons are

caused by tilt of Earth’s axis as it moves around the sun.

The Earth’s orbit around the sun is NOT a perfect circle. It is an ellipse.

EQUINOXES literally means "equal night". This occurs twice a year.

The vernal equinox occurs March 21 in the Northern Hemisphere, marks the start of spring.

The autumnal equinox occurs September 22 in the Northern Hemisphere, marks the start of autumn.

SOLSTICES---occur on the two days each year when the sun is directly overhead at latitude 23.5 north or 23.5 south.

Winter solstice is the shortest day of the year. In the Northern Hemisphere. It occurs on December 21 and marks the beginning of winter.

The Summer Solstice is the longest day of the year. It occurs on June 21 and marks the beginning of summer.

THANK YOU!

ACTIVITY 8

WHAT TO DO:1. Study the figure carefully. It shows the Earth at different locations along its orbit around the Sun. Note that the axis of Earth is not perpendicular to its plane of orbit; it is tilted. The letter “N” refers to the North Pole while “S” refers to the South Pole.

2. Answer the following questions briefly.A. In which month is the North Pole tilted toward the Sun- in June or December? Why?B. In which month is the North Pole tilted away from the Sun- in June or December? Why?C. In June, Which hemisphere receives direct rays from the Sun?D. In December, which hemisphere receives direct rays from the Sun?E. Predicting: How might Earth’s weather be different if Earth were not tilted on its axis?

CONCLUSION:

What determines the change in seasons? Why

does Earth have seasons?