// The Moon Mr. Harpers science mini lesson with audio Click on the speaker icon to hear the words
Some planets in our solar system have moons that orbit around them. Mercury and Venus dont have a moon. Earth has 1 moon. Mars has 2 moons. Jupiter has more than 60. Saturn also has more than 60 moons. Uranus has 27. Neptune has 13. Jupiter with its 4 biggest moons. Mars is orbited by 2 moons
// Earth has many man-made satellites in orbit around it. Some relay TV and telephone signals. Some send pictures of Earths weather.
// The science term for a moon is natural satellite. But most people call them moons so we will too.
// Earths moon is made of the same kinds of materials as Earth. It is rocky. But the moon has little or no atmosphere or water. There is probably no life there at all.
Astronauts from Earth first traveled to the moon in 1969. In all, 12 people have walked on the moon. The last one was in 1972. Earth
Astronauts had to wear pressurized space suits to be able to breathe, because there is no air on the moon. Even with the sun shining, the sky is black because there is no atmosphere.
The moon has much less mass (its smaller and weighs less) than Earth. That makes moons gravitational attraction much less than Earths. A person on the moon would weigh about 1/6 th of their Earth weight.
25,000 miles circumference The moon orbits at about 220,000 miles from Earth. Thats about 9 times Earths circumference. (Circumference is the distance all the way around the Earths equator).
// On Earth, we can only see the part of the moon that is illuminated by sunlight. As the moon orbits Earth during a month we see the light change. These different looks are called phases of the moon.
// The moon completes a phase cycle every 28 days because thats how long it take the moon to orbit Earth.
If you are on the moon, Earth has phases too. These are real photos of Earth taken from the moon.
// If you were on the moon you would see Earth turn every 24 hours. The periods of the moons rotation (spinning on axis), and its orbit and are the same, about 28 days. The rotation is also in the same direction as as its orbit. What this means is that the same side of the moon is always facing Earth.
// Only astronauts have seen the far side of the moon. It is often called the dark side of the moon but its only dark half the time just like any planet or moon.
Sometimes the moon passes directly between Earth and the sun. This makes a shadow on parts of Earth called a solar eclipse. Many people damage their eyes looking directly at the sun during a solar eclipse. Most sunglasses cant protect you. Moons shadow Earthss shadow Partial eclipse Total solar eclipse
// A lunar eclipse is when Earth is between the sun and moon. It takes a few hours for the Earths shadow to pass over the moon.
// The moon can help us see on a dark night. The moon doesnt make light, but it reflects the suns light.
// Another interesting effect of the moon is the changing tides that happen every day along the coast between land and sea.
// The moon stays in orbit around Earth because of Earths gravity. But the moons gravity pulls on Earth, too. The liquid ocean changes shape and bulges a few feet toward the moon during high tide. high tide low tide
Moon Tides on brainpop.com To learn more, check out these Brainpop cartoons Moon Solar system on brainpopjr.com