八大行星是那些

八大行星是那些
八大行星是那些

八大行星是那些
从太阳开始水星→金星→地球→火星→木星→土星→天王星→海王星

水星、金星、地球、火星、木星、土星、天王星、海王星

大概有金星、水星、木星、火星、土星、天王星、海王星和地球

Our solar system consists of the sun, eight planets and their moons, an asteroid belt, and many comets and meteors. The sun is the center of our solar system; the planets, their moons, the asteroids, ...

全部展开

Our solar system consists of the sun, eight planets and their moons, an asteroid belt, and many comets and meteors. The sun is the center of our solar system; the planets, their moons, the asteroids, comets, and other rocks and gas all orbit the sun.
The eight planets that orbit the sun are in order from the sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, . A belt of asteroids lies between Mars and Jupiter. These objects all orbit the sun in roughly circular orbits that lie in the same plane, the ecliptic .
The largest planet is Jupiter. It is followed by Saturn, Uranus, Neptune, Earth, Venus, Mars and Mercury. Jupiter is so big that all the other planets could fit inside it.
The Inner Planets vs. the Outer Planets
The inner planets are quite different from the outer planets .
The inner planets are: Mercury, Venus, Earth, and Mars. They are relatively small, composed mostly of rock, and have few or no moons.
The outer planets include: Jupiter, Saturn, Uranus and Neptune. They are mostly huge, mostly gaseous, ringed, and have many moons
Temperatures on the Planets
Generally, the farther from the Sun, the cooler the planet. Differences occur when the greenhouse effect warms a planet ,like Venus, surrounded by a thick atmosphere.
The outer, gaseous planets are much less dense than the inner, rocky planets.
The Earth is the densest planet. Saturn is the least dense planet; it would float on water.
The Mass of the Planets
Jupiter is by far the most massive planet; Saturn trails it. Uranus, Neptune, Earth, Venus and Mars are orders of magnitude less massive.
Gravitational Forces on the Planets
The planet with the strongest gravitational attraction at its surface is Jupiter. Although Saturn, Uranus, and Neptune are also very massive planets, their gravitational forces are about the same as Earth. This is because the gravitational force a planet exerts upon an object at the planet's surface is proportional to its mass and to the inverse of the planet's radius squared.
A Day on Each of the Planets
A day is the length of time that it takes a planet to rotate on its axis . A day on Earth takes almost 24 hours.
The planet with the longest day is Venus; a day on Venus takes 243 Earth days.
The planet with the shortest day is Jupiter; a day on Jupiter only takes 9.8 Earth hours! When you observe Jupiter from Earth, you can see some of its features change.
The Average Orbital Speed of the Planets
As the planets orbit the Sun, they travel at different speeds. Each planet speeds up when it is nearer the Sun and travels more slowly when it is far from the Sun .

收起