ทางช้างเผือก คืออะไร What is galaxy?
หลุมดำคืออะไร What is black hole?
ระบบสุริยะ คืออะไร What is Solar System?
ระบบสุริยมีดาวกี่ดวง How many Planet contain in Solar System?
พายุสุริยะคือ อะไร What is Solar Storm?
Dwarf Planet ดาวเคราะห์
Why Do Stars Have Names?
Do Stars Fall From the Sky?
Why Do Stars Twinkle?
How Many Stars Are There ?
Do Stars Come in Different Shapes?
How Hot Is the Sun?
Can you make electricity from the heat of the sun?
Why Does the Sun Seem to be Moving?
How Bright is the Sun?
Did people ever worship the sun?
Why does the shape of the moon change?
What are shadows on the moon?
The sun is our largest member of our Planetary System. It weighs about five hundred times as much as anything else in our Planetary System. Wow, now that is a lot! It is the only planet or star in our Planetary System large enough for its center to undergo nuclear fusion. It is able to produce so much energy that it shines. The planets of our Planetary System are so much smaller that nuclear fusion can't occur. Their surfaces are cold. They only shine by reflecting light from the sun. All of our planets do orbit the sun.
The moon is much smaller and lighter than the Earth. Because of this, its force of gravity is much weaker, one sixth of the Earth's. So, our moon is unable to hold an atmosphere.
1. The moon is the only world, apart from the Earth, that people have actully walked on. Twelve U.S astronauts landed on the moon between 1969 and 1972 in the Apollo missions.
2. The moon always shows the same face to the Earth because it takes the same time for it to spin around once as it does for it to orbit the Earth.
3. The moon's suface is covered by craters caused by rocks, called meteorites, that crashed into it from space.
The stars are born within giant gas clouds. Dust swirls deep into the gas clouds. This forms pockets of gas. Deep down in a cloud a pocket of gas grows big enough that the gravity pulls more gas into the cloud. Then gradually, the star's pocket of gas begins to contract, and it slowly warms up.
Our solar neighborhood is an exciting place. The Solar System is full of planets, moons, asteroids, comets, minor planets, and many other exciting objects. Learn about Io, the explosive moon that orbits the planet Jupiter, or explore the gigantic canyons and deserts on Mars.