A LOOK AT EARTH


click on the picture
for a larger view.

THIRD PLANET FROM THE SUN

Earth is shaped like a sphere. Earth has the things that are needed for life - the right amount of sunlight, air and water. Because Earth is close enough to the Sun the living things on Earth receive the heat and light they need to grow. Earth is surrounded by a blanket of air called the atmosphere . Oxygen is one of the main gases in the atmosphere. Earth rotates on its axis once every 24 hours. This is how we have day and night. Earth has one moon.


EARTH'S SURFACE

Earth's surface is about 70 percent water. Water helps to control Earth's weather and climate. Water breaks up rocks into soil so that plants can grow. There are seven large land areas called continents that make up the rest of the surface. On these continents are mountains, plains, volcanoes, deserts, rainforests and glaciers.

THE SEASONS

It takes 365 days for Earth to travel around the sun (revolve). At the same time. Earth rotates on its axis. The four seasons are the result of the tilt of the Earth's axis. During the winter the Northern Hemisphere is tilted away from the Sun and the days are shorter and cooler.

When it is summer in the Northern Hemisphere, the North Pole is tilted towards the Sun. This tilting causes the Sun to appear higher in the sky during the summer than during the winter. The higher Sun means more hours of daylight and direct sunlight. This makes it hotter on the surface of the Earth.

When the sunlight reaches the ground it is absorbed into the grass, rocks, and soil and becomes heat energy.



SPACE INDEX

photo of the Earth - as seen by Apollo 17 crew
Image courtesy of Johnson Space Center.

web page by J.Giannetta
2005
updated April 2009