Earth in Space

Earth in December

In December, people in the Southern Hemisphere receive the most direct sunlight, so it is summer there. At the same time, the sun's rays in the Northern Hemisphere are more slanted and there are fewer hours of daylight. So it is winter in the Northern Hemisphere.

Where is the Earth tilted in June?

In June, the north end of the Earth's axis is tilted toward the sun. In the Northern Hemisphere, the noon sun is high in the sky and there are more hours of daylight than darkness. The combination of direct rays and more ours of sunlight heats the surface more in June than at any other time of the year. It is summer in the Northern Hemisphere. At the same time south of the equator, the sun's energy is spread over a larger area. The sun is low in the sky and days are shorter than nights. The combination of less direct rays and fewer hours of sunlight heats Earths's surface less than at any other time of the year. It is winter in the Southern Hemisphere.

Earth movement through space

Two ways: rotation, spinning on its axis, and revolution, orbiting around the sun.

Seasons

Occur in most places outside the tropics and polar regions: winter, spring, summer, autumn.

Earth's seasons

Occur because its axis is tilted as it goes around the sun. Earth's axis is always tilted at an angle of 23.5. Large, very powerful earthquakes can change the tilt by making the day less than a millisecond shorter.

Egyptians

Among first to study stars using appearance of Sirius to predict the flood of the Nile.

Day and Night

Caused by rotation of earth to the east. It takes 24 hours to rotate once (a day)

Why is it warmer near the equator not the poles?

Direct sunlight at equator vs steep angle of sunlight at poles spread out over a wider area.

What is an equinox?

It is the halfway point between the solstices, neither hemisphere is tilted toward or away from the sun. This occurs twice a year, when the noon sun is directly overhead at the equoatr. Each of these days is known as an equinox.

What does equinox mean?

It means equal day and night are each about 12 hours long everywhere on Earth.

What is the autumnal equinox and when does it occur

It occurs around september 22. It marks the beginning of fall in the Northern Hemisphere.

What is a March and September Equinoxes

Neither end of Earth's axis is tilted toward the sun. Both hemispheres receive the same amount of energy.

Astronomy

Study of the moon, stars, and other objects in space.

What would happen to temperatures if the Earth's axis were straight up and down relative to its orbit.

Temperatures would remain fairly constant.

Is the change of Seasons due to Earth's distance from the Sun?

The change in seasons is not caused by changes in Earth's distatnce from the sun. In fact, Earth is farthest from the sun when it is summer in the Northern Hemisphere

Revolution

The movement of one object around another. (Earth's movement around the sun)

What is the June Solstice?

The north end of the Earth's axis is tilted toward the sun. It is the summer in the Northern Hemisphere and winter in the Southern Hemisphere.

Orbit

The path of revolution. The Earth's path around the sun, for instance. It is not quite circular, but elongated or like an ellipse.

What is the December Solstice?

The south end of the Earth's axis is tilted toward the sun. It is summer in the Southern Hemisphere and winter in the Northern.

Rotation

The spinning of Earth on its axis that runs through the North and South Poles.

What happens around Dec 21

The sun is farthest south of the equator. This is the winter solstice in the Northern Hemisphere and the summer solstice in the Southern Hemisphere.

Solstices

The sun reaches its greatest distance north or south of the equator twice each year. Each of these days, when the sun is farthest north or south of the equator, is known as a solstice. The day when the sun is farthest north of the equator is the summer solstice in the Northern Hemisphere. It is also the winter solstice in the Southern Hemisphere. This solstice occurs around June 21 each year. It is the longest day of the year in the Northern Hemisphere and the shortest day of the year in the Southern Hemisphere.

What is the vernal spring and when does it occur.

The vernal spring equinox occurs about March 21 and marks the begninning of spring in the Northern Hemisphere.