1. Astronomy

2. Earth in Space Earth moves through space in two major ways: rotation and revolution. Earth moves through space in two major ways: rotation and revolution. The imaginary line that passes through the Earth’s center and the North and South poles is Earth’s axis. The spinning of Earth on it’s axis is called rotation. The imaginary line that passes through the Earth’s center and the North and South poles is Earth’s axis. The spinning of Earth on it’s axis is called rotation. Earth’s rotation causes day and night. Earth’s rotation causes day and night. As the Earth rotates eastward,the sun appears westward across the sky. As the Earth rotates eastward,the sun appears westward across the sky.

3. The Seasons on Earth Near the equator, the sunlight strikes Earth’s surface more directly and is less spread out than near the poles. Near the equator, the sunlight strikes Earth’s surface more directly and is less spread out than near the poles. Earth has seasons because it’s axis is tilted as it revolves around the sun. Earth has seasons because it’s axis is tilted as it revolves around the sun. Summer and winter are caused by Earth’s tilt as it revolves around the sun. Summer and winter are caused by Earth’s tilt as it revolves around the sun. The days when Earth is most tilted toward the sun,June 21 and December 21 are called solstice The days when Earth is most tilted toward the sun,June 21 and December 21 are called solstice The days when Earth is not tilted toward the sun are called equinoxes.

4. Earth in Space In addition to rotating on its axis, Earth travels around the sun. Revolution is the movement of one object around another. In addition to rotating on its axis, Earth travels around the sun. Revolution is the movement of one object around another. One complete revolution of Earth around the sun is called a year. One complete revolution of Earth around the sun is called a year. Earth follows a path, or orbit, as it revolves around the sun. Earth follows a path, or orbit, as it revolves around the sun. Earth’s orbit is not quite circular. It’s slightly elongated circle or ellipse. Earth’s orbit is not quite circular. It’s slightly elongated circle or ellipse.

5. Gravity and Motion What keeps Earth and Moon in Orbit? A force is a push or a pull. A force is a push or a pull. Newton hypothesized that the force that pulls an apple to he ground also pulls the moon toward Earth,keeping it in orbit. This force, called gravity, attracts all objects toward each other. Newton hypothesized that the force that pulls an apple to he ground also pulls the moon toward Earth,keeping it in orbit. This force, called gravity, attracts all objects toward each other. Newton’s law of universal gravitation states that every object in the universe attracts every other object. Newton’s law of universal gravitation states that every object in the universe attracts every other object.

6. Gravity The strength of the force of gravity between two objects depends on 2 factors: the masses of the objects and the distance between them. The strength of the force of gravity between two objects depends on 2 factors: the masses of the objects and the distance between them. Mass is the amount of matter in an object. Because Earth is so massive, it exert a much greater force on you than a book. Mass is the amount of matter in an object. Because Earth is so massive, it exert a much greater force on you than a book. Earth exerts a gravitational force on the moon, large enough to keep the moon in orbit. The moon also exerts a gravitational force on Earth. Earth exerts a gravitational force on the moon, large enough to keep the moon in orbit. The moon also exerts a gravitational force on Earth. The force of gravity on an object is known as its weight. You weigh less on the moon because the moon is much less massive than Earth, so the pull of the moon’s gravity on you would be less. The force of gravity on an object is known as its weight. You weigh less on the moon because the moon is much less massive than Earth, so the pull of the moon’s gravity on you would be less.

7. Gravity, Mass and Distance The strength of the force of gravity between two objects depends on their masses and the distance between them. The strength of the force of gravity between two objects depends on their masses and the distance between them.

8. Inertia Why doesn’t the Earth crash into the moon or sun? Gravity and Inertia Why doesn’t the Earth crash into the moon or sun? Gravity and Inertia Inertia is the tendency of an object to resist a change in motion. Inertia is the tendency of an object to resist a change in motion. The more mass an object has the greater its inertia. The object with greater inertia is more difficult to start and stop. The more mass an object has the greater its inertia. The object with greater inertia is more difficult to start and stop. Newton concluded that 2 factors-inertia and gravity-combine to keep Earth in orbit around the sun and the moon in orbit around the Earth. Newton concluded that 2 factors-inertia and gravity-combine to keep Earth in orbit around the sun and the moon in orbit around the Earth.

9. Moon Phases The moon is lit by sunlight bouncing off it. That light reaches Earth as moonlight. The moon is lit by sunlight bouncing off it. That light reaches Earth as moonlight. You will see that the moon’s shape appears to change and that the time of night and day that you can see the moon also changes. You will see that the moon’s shape appears to change and that the time of night and day that you can see the moon also changes. The different shapes that the moon appears to have are called the moon’s phases. The different shapes that the moon appears to have are called the moon’s phases. The moon goes through eight phases as it revolves around the Earth once every 27.3 days. The moon goes through eight phases as it revolves around the Earth once every 27.3 days. The phase that you see depends on how much of the sunlit part of the moon you can see. The phase that you see depends on how much of the sunlit part of the moon you can see. The lit part you can see depends on the positions of Earth, moon, and sun. The lit part you can see depends on the positions of Earth, moon, and sun.

10. Moon Phases New Moon-sunlit side faces away from Earth. New Moon-sunlit side faces away from Earth. Waxing Crescent Waxing Crescent First quarter-you can see half of the sunlit side of the moon. First quarter-you can see half of the sunlit side of the moon. Waxing Gibbous Waxing Gibbous Full Moon Full Moon Waning Gibbous Waning Gibbous Third Quarter Third Quarter Waning Crescent Waning Crescent

11. Eclipse An eclipse occurs when one object in space casts a shadow on another. An eclipse occurs when one object in space casts a shadow on another. During a solar eclipse,the moon blocks light from the sun, preventing sunlight from reaching parts of the Earth’s surface. Solar eclipse occurs when a new moon blocks your view from the sun. During a solar eclipse,the moon blocks light from the sun, preventing sunlight from reaching parts of the Earth’s surface. Solar eclipse occurs when a new moon blocks your view from the sun. During a lunar eclipse, Earth blocks sunlight from reaching the moon’s surface. Lunar eclipses occur only when there is a full moon because the moon is closest to Earth’s shadow at that time. During a lunar eclipse, Earth blocks sunlight from reaching the moon’s surface. Lunar eclipses occur only when there is a full moon because the moon is closest to Earth’s shadow at that time. The moon’s reddish tint occurs because Earth’s atmosphere bends some sunlight toward the moon. The moon’s reddish tint occurs because Earth’s atmosphere bends some sunlight toward the moon.

12. Solar Eclipse Total Solar Eclipse- The very darkest part of the moon’s shadow is called umbra, is coned shaped. Total Solar Eclipse- The very darkest part of the moon’s shadow is called umbra, is coned shaped. Partial Solar Eclipse-the largest part of the shadow is called penumbra. Partial Solar Eclipse-the largest part of the shadow is called penumbra.

13. Lunar Eclipse Total Lunar Eclipse-when the moon is n the Earth’s umbra, you see a total lunar eclipse. Total Lunar Eclipse-when the moon is n the Earth’s umbra, you see a total lunar eclipse. Partial Lunar Eclipse occurs when the moon passes partly into the umbra of the Earth’s shadow. Partial Lunar Eclipse occurs when the moon passes partly into the umbra of the Earth’s shadow.

14. Tides Tides are controlled mostly by he pull of gravity between the Earth and moon. Tides are controlled mostly by he pull of gravity between the Earth and moon. Tides usually change four times a day. Every 6 hours there’s a change in tides. Tides usually change four times a day. Every 6 hours there’s a change in tides. Spring Tide is when Earth, the sun and the moon are in a straight line. Spring Tide is when Earth, the sun and the moon are in a straight line. Neap Tide occurs when the moon is at a right angle to the sun. Neap Tide occurs when the moon is at a right angle to the sun.

15. Earth’s Moon The moon surface has dark, flat areas called marias. The moon surface has dark, flat areas called marias. The moon’s surface is marked by large round pits called craters. These craters were caused by the impacts of meteoroids, chunks of rock or dust from space. The moon’s surface is marked by large round pits called craters. These craters were caused by the impacts of meteoroids, chunks of rock or dust from space. Temperatures on the moon vary so much because it has no atmosphere. Temperature range from extremely hot to extremely cold. Temperatures on the moon vary so much because it has no atmosphere. Temperature range from extremely hot to extremely cold. The moon has no water. The moon has no water.

16. Origin of the Moon Scientists theorize that a planet -sized object collided with Earth to form the moon (4.6 billion years ago). This theory is called the collision-ring theory. Scientists theorize that a planet -sized object collided with Earth to form the moon (4.6 billion years ago). This theory is called the collision-ring theory.

17. What was the Space Race? The space race was the rivalry between the U.S and the Soviet Union to explore space. It began in 1957,when the Soviets launched the satellite Sputnik 1 into orbit. The U.S. responded by speeding up its own space program, which led to the Apollo moon mission in the 1960’s. The space race was the rivalry between the U.S and the Soviet Union to explore space. It began in 1957,when the Soviets launched the satellite Sputnik 1 into orbit. The U.S. responded by speeding up its own space program, which led to the Apollo moon mission in the 1960’s. A satellite is an object that revolves around another object in space. Sputnik 1, launched by the Soviets, was the first artificial satellite to orbit Earth. A satellite is an object that revolves around another object in space. Sputnik 1, launched by the Soviets, was the first artificial satellite to orbit Earth.

18. How are Space Shuttles and Space Stations used? A space shuttle is a spacecraft that can carry a crew into space, return to Earth, and be reused for the same purposes. NASA has used space shuttles to perform many important tasks. These include taking satellites into orbit, repairing damaged satellites, and carrying astronauts and equipment to and from space stations. A space shuttle is a spacecraft that can carry a crew into space, return to Earth, and be reused for the same purposes. NASA has used space shuttles to perform many important tasks. These include taking satellites into orbit, repairing damaged satellites, and carrying astronauts and equipment to and from space stations.

19. What is a Space Station? A space station is a large artificial satellite. A space station provides a place where long-term observations experiments can be carried out in space. In the 1980s, the US and 15 other countries decided to construct the International Space Station (ISS). A space station is a large artificial satellite. A space station provides a place where long-term observations experiments can be carried out in space. In the 1980s, the US and 15 other countries decided to construct the International Space Station (ISS).

20. How are Space Probes Used? A space probe carries scientific instruments but has no human crew. A space probe collects data about the solar system and sends the information back to Earth. A space probe carries scientific instruments but has no human crew. A space probe collects data about the solar system and sends the information back to Earth.

21. What are conditions like in space? Conditions in space that differ from those on Earth include near vacuum, extreme temperatures and microgravity. Many types of engineers and scientists have worked together to respond to the challenges of space. Conditions in space that differ from those on Earth include near vacuum, extreme temperatures and microgravity. Many types of engineers and scientists have worked together to respond to the challenges of space. Space has no air and is nearly a vacuum, a place that is empty of all matter. Space has no air and is nearly a vacuum, a place that is empty of all matter. Astronauts in orbit experience a feeling of weightlessness, or microgravity. Astronauts in orbit experience a feeling of weightlessness, or microgravity. Astronauts feel weightless because they are falling through space with their spacecraft. They don’t fall to Earth because their inertia keeps them moving forward. Astronauts feel weightless because they are falling through space with their spacecraft. They don’t fall to Earth because their inertia keeps them moving forward.

22. How has space technology benefited people? A space spinoff is an item that has been used on Earth but was originally developed for use in space. Often such spinoffs are modified somewhat for use on Earth. The space program has led to the development of many thousands of products, new materials, medical devices, and communication satellite. A space spinoff is an item that has been used on Earth but was originally developed for use in space. Often such spinoffs are modified somewhat for use on Earth. The space program has led to the development of many thousands of products, new materials, medical devices, and communication satellite. Satellites are used for communication and collecting weather data, and other scientific data. Satellites are used for communication and collecting weather data, and other scientific data. Observation satellites are used for many purposes, including tracking weather systems, mapping Earth’s surface, and observing changes in Earth’s envoronment. Observation satellites are used for many purposes, including tracking weather systems, mapping Earth’s surface, and observing changes in Earth’s envoronment.