How do you know the Earth and moon is moving?
Sometimes it is easy to know objects move.It was easy for you to see a ball and players move.It may be hard to know that other objects move.You did not see or feel yourself move away from your books.
Both the Earth and moon move.It is easy to think that the moon moves.You can watch the moon change its place in the night sky.It is not so easy to think that the Earth moves.You cannot watch the Earth change its place.
TWO NATURAL SATELLITES
If you traveled out in space,you would see that the Earth and moon move.They both move around other objects in space.The Earth moves around the sun.The moon moves around the Earth.An object that moves around a larger object is called a satellite.The moon is a satellite of the Earth.
Scientists always know where the moon is in space.The moon follows a path around the Earth.The path is called an orbit.A satellite follows an orbit or path around another object.
The moon is a natural satellite of the Earth.The moon was not made by people.The Earth has other satellites,too.These satellites are machines made by people.They are used by people to lear more about space and the Earth.
TWO MOVEMENTS IN SPACE
Revolving means that one object goes around another object.The revolving object follows an orbit as it moves.Our moon revolves in an orbit around the Earth.The moon takes about 28 days to revolve around the Earth.
The Earth is revolving,too.It follows an orbit around the sun.The Earth follows a larger orbit than the moon.So,the Earth takes a longer time to revolve.It takes the Earth one year to revolve around the sun.
Rotating means that an object spins.The Earth rotates,the Earth rotates one time every 24 hours.The moon does not rotate as fast as the Earth.The moon takes about 28 days to rotate one time.
The moon does not make its own light.Moonlight is really sunlight.Light from the sun shines on the moon.The light bounces off the moon and shines on the Earth.We see this light from earth.We call the light moonlight.
Half of the moon’s surface is always facing the sun.The part facing the sun gets sunlight.The half facing away from the sun is dark.Sometimes you can see the whole lighted side of the moon.At other times,we can see only part of the lighted side.The amount of the lighted side that you see changes from night to night.The lighted part of the moon that you see from Earth is called a phase.
Moon phases change in a cycle.The cycle lasts for about 29 1/2 days.The moon’s cycle begins with the new moon phase.During the new moon,all of the lighted side faces away from the Earth.You cannot see the new moon.You see a small part of the moon on the next night.Each night you see more.People say the moon is waxing.A waxing moon has more of its lighted side showing each night.
You see all of the lighted side of the moon during the full moon phase.The full moon happens halfway through the phase cycle.You see less of the moon each night after the full moon.People say the moon is waning.A waning moon has less of its lighted side showing each night.
People have names for the shapes of the moon during its cycle.Full moon and new moon are two of eight moon phase.The moon does not really shape.