Our solar neighborhood is really an exciting place. It is full of different heavenly bodies such as planets, moons, asteroids, meteors, comets, and many other exciting objects. Let us learn more about them.
What is a planet?
Planets are large natural objects that orbit, or revolve around, stars. You are standing on one at this moment! Yes, Earth is a planet too. Today, we have eight planets orbit the star called the Sun. In order, from the closest to the Sun, these planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
While some of the planets are small, rocky bodies with a solid ground – Mercury, Venus, Earth and Mars; the others are big gas giants – Jupiter, Saturn, Uranus, and Neptune.
Earlier, the scientists were of the opinion that there are nine planets including Pluto, but in 2006, modern scientists came up with three compulsory conditions to award planet – hood to any heavenly body :
- A planet must revolve around the Sun
- Be spherical in shape
- Its orbit must be free of other small objects
Unfortunately, Pluto failed to meet the third condition and had to step down from being a planet to a “dwarf planet”.
So far, hundreds of worlds beyond our solar system have been discovered and many new ones are in the process of being discovered. Scientists believe some of these planets may sustain alien life. Well, no one knows for sure, but there is a high probability that an alien kid elsewhere in the galaxy is also reading about us and the Earth in an article like this!
What is a star?
Stars are giant spheres of superhot gas, generally made up of hydrogen and helium. Stars get so hot and bright because of a process called nuclear fusion that takes place inside them. Nuclear fusion is a process in which hydrogen gas gets converted into helium, releasing light and heat. Though it seems to us that the stars twinkle in the night, they really don’t. What happens is that the light of the stars has to travel through various layers of our atmosphere during which it bounces around, and we feel that the stars are twinkling.
What is a moon?
Moons are natural objects that orbit planets. There are about 170 moons in our Solar System that revolve around different planets. Our Moon was probably made billions of years ago when a large object hit the Earth. Many small rocks were thrown out by the explosion and they started revolving around the Earth. With the due course of time, they got fused together, cooled down and became the Moon.
How is a planet different from a star?
What are the characteristics of a star?
- A star has its own light.
- Stars do not undergo any noticeable change in their position.
- All stars have very high temperatures.
- There are billions of stars in the galaxy.
What are the defining characteristics of a planet?
- A planet has no light of its own. It shines by reflecting the light of the sun.
- Planets do not twinkle.
- Planets move around the stars and there is a noticeable shift in their position in the sky.
- Planets have low temperatures.
- There are only nine planets in the solar system.
- Similarities between stars and planets
- Planets and stars both orbit other stars. This is a similarity between the two heavenly objects.
Difference between a moon and a planet
If an object revolves around the Sun, it is called a planet; however, if it circles some other heavenly body (generally a planet) other than the Sun, it is called a moon.
Are stars planets or suns?
A star is called a “sun” if it is the center of a planetary system. There is a fair chance of having a large percentage of the stars in the galaxy that have planets orbiting them. You can call all of them “suns”.
What is the Sun?
The Sun is one of the million stars that are present in our galaxy. It is placed at the center of our solar system. It is a huge ball of gases with millions of degrees of heat. Because of its large size, it has a strong gravitational pull which helps in keeping the Earth and the other planets in line. Without the gravitational pull of the Sun, all planets would go spinning off into space.
Without the Sun, there would be no life on Earth and it would be frozen solid. The Sun is also responsible for change in seasons, as the Earth travels around the Sun, on its orbit.
9 Interesting facts about stars, planets and moons
- The Sun’s light reaches the Earth in eight minutes. This is known as the speed of light.
- Water was discovered on the moon in November 2009
- The footprints of Apollo astronauts are still visible on the Moon. They will remain visible for at least 10 million years more as there is no atmosphere or wind-erosion on the Moon.
- Scientists usually refer to moons in the galaxy as planetary satellites. On the other hand, human-made satellites are called artificial moons.
- You can see about 7,000 stars with naked eyes from Earth.
- Many stars and constellations are named after ancient gods and animals that they resemble.
- Every star you see in the sky is larger and brighter than the Sun.
- The largest planet in the solar system is Jupiter and Mercury is the smallest.
- Neptune is the coldest planet and Jupiter is the hottest planet.