Seasons

What is the approximate age of the Earth according to the sources?

4.54 billion years

What is the approximate equatorial diameter of the Earth?

7,900 miles

What is the approximate polar diameter of the Earth?

7,926 miles

What is the shape of the Earth described as in the sources?

Oblate spheroid

As viewed from the North Pole, in which direction does the Earth rotate?

Counterclockwise

As viewed from the South Pole, in which direction does the Earth rotate?

Clockwise

What is the approximate maximum rotational velocity of the Earth at the equator?

1,038 mph

What is the approximate rotational velocity of the Earth at 34˚ latitude?

860 mph

What is the approximate rotational velocity of the Earth at 66.5˚ latitude?

414 mph

What is the rotational velocity of the Earth at 90˚ latitude?

0 mph

Approximately how long does it take for the Earth to complete one rotation as viewed from the Sun?

23 hr 56’ 04”

Approximately how long does it take for the Earth to complete one rotation as viewed from a fixed point?

24 hrs

Approximately how long is the Earth's orbit around the sun?

~584,088,000 miles

What is the approximate orbital velocity of the Earth around the sun?

~67,100 mph

What is the shape of the Earth's orbit around the sun?

Elliptical

What is eccentricity a measure of?

How much an ellipse differs from a perfect circle

What is the approximate eccentricity of Earth's orbit?

0.0167

When does Perihelion occur for the Earth?

January 3

Approximately how far is the Earth from the sun at Perihelion?

91.4 million miles

When does Aphelion occur for the Earth?

July 3

Approximately how far is the Earth from the sun at Aphelion?

94.5 million miles

What causes differential heating of the Earth's surface?

Variations in solar intensity

What are the two main types of variations in solar intensity discussed in the sources?

Location and Time

How does the amount of solar intensity vary based on location?

It varies by latitude, with warmer temperatures at the equator and colder temperatures at the poles.

What is the primary reason for the variation in solar intensity based on location (latitude)?

The angle of the sun on the surface

According to the sources, the steeper the angle of the sun on the surface, the ____ the heating.

more intense

Where are high sun angles generally experienced on Earth?

In the Tropics

Where are medium sun angles generally experienced on Earth?

At Midlatitudes

Where are low sun angles generally experienced on Earth?

In the Arctic

What is the secondary reason mentioned for colder temperatures at higher latitudes (shallower sun angles)?

Sunlight travels through more atmosphere, leading to more energy loss.

How does the amount of solar intensity vary based on time of year?

It changes from one time of year to another, resulting in seasons.

Why is it generally warmer during the summer and colder during the winter?

The angle of the sun on the surface is steeper during the summer and shallower during the winter.

What is the primary reason why the angle of the sun varies throughout the year?

The tilt of the Earth’s axis

What is the approximate tilt of the Earth's axis relative to the Sun's axis?

23.5˚

How often does the season change according to the 'Seasons Rule of Three' mentioned in the sources?

Every 3 months

Around what time of the month do the seasons typically change according to the sources?

The third week

According to the sources, is the distance to the sun a significant factor in causing the seasons?

It has a minor influence.

When is the Earth closest to the sun (Perihelion) in relation to the Northern Hemisphere seasons?

Winter

When is the Earth farthest from the sun (Aphelion) in relation to the Northern Hemisphere seasons?

Summer

What is consistent about the orientation of the Earth's axis throughout the year?

The Northern Hemisphere axis points to the North Star (Polaris).

What is denoted by the Tropic of Cancer and the Tropic of Capricorn?

The limit of vertical noon sun, at least once a year.

What is the latitude of the Tropic of Cancer?

23.5˚N

What is the latitude of the Tropic of Capricorn?

23.5˚S

What is denoted by the Arctic Circle and the Antarctic Circle?

The limit of 24 hrs of daylight/darkness at least once a year.

What is the latitude of the Arctic Circle?

66.5˚N

What is the latitude of the Antarctic Circle?

66.5˚S

At 90˚N latitude, what is the approximate maximum sun angle and when does it occur?

90˚ on 3/21

At 90˚N latitude, what is the approximate minimum sun angle and when does it occur?

0˚ on 9/21-3/21

According to the sources, what is the approximate difference between the maximum and minimum sun angle at any location on Earth?

47˚

At 0˚N latitude (the Equator), when do the maximum sun angles of 90˚ occur?

6/21 & 12/21