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How many planets in the solar system? This question has always occurred to us, and although the answer to this question is supposed to be easy, it is not accurate for everyone. Especially after discovering that one of these planets does not have the characteristics and qualities of a planet, so it was demoted to a dwarf planet. So what is this planet? How many planets in the solar system? This is what we will learn about on the reference site in our next article.
What is the solar system
The solar system is approximately 4.6 billion years old, and our solar system consists of the sun, planets revolving around it, dozens of moons, and millions of asteroids, comets, and meteorites due to gravity. It is located within the Milky Way galaxy, and there are tens of billions of other solar systems in the Milky Way galaxy, and some of these systems contain more than one star, and are then called binary-star systems if they contain two stars, and multi-star systems if they contain three stars or more. .[١]
Also read: One of the common characteristics among the planets of the group
How many planets in the solar system
The number of planets in the solar system is eight. This is after excluding Pluto and considering it a dwarf planet, because it does not have the specifications and characteristics of the other planet. These planets, according to their proximity to the sun, are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
What are the bodies of the solar system?
The bodies of the solar system are divided into three categories:
planets
A planet is a celestial body that has an orbit around the sun. It has a gravity resulting from its possession of mass, and gravity is responsible for creating a balance that causes the planets to form in spherical or elliptical shapes. Its gravity is responsible for expelling neighboring bodies from the planet’s orbit. These planets are:
- Mercury: Mercury is the closest planet of the solar system to the sun, and it is also the smallest and slightly larger than Earth. It revolves around the sun in just 88 days. Because it is so close to the sun (about two-fifths of the distance between Earth and the sun), Mercury experiences dramatic temperature changes between night and day. Daytime temperatures reach 840 F (450 C), hot enough to melt lead. Meanwhile on the night side, temperatures drop to minus 290 degrees Fahrenheit (minus 180 degrees Celsius).
- Flower: Venus The second planet in distance from the Sun, Venus is Earth’s twin in size. Radar images under its atmosphere reveal that its surface has various mountains and volcanoes. It is also hotter than Mercury. The average temperature on the surface of Venus is 900 F (465 C). Surprisingly, Venus rotates slowly from east to west, which is the opposite direction for most other planets.
- Earth: The third planet in distance from the sun, two-thirds of the Earth is covered by oceans. It is the only planet known to have life. The planet orbits the sun at more than 18 miles per second (29 km per second).
- Mars: The fourth planet in distance from the sun, a cold, desert-like place covered in dust. This dust is composed of iron oxides, giving the planet its distinctive red colour. Mars is similar to Earth in terms of terrain, with mountains, valleys, and canyons, and storm systems ranging from hurricane-like dust devils to dust storms sweeping across the planet.
- Buyer: The fifth planet in distance from the sun, it is a gas giant and is the largest planet in our solar system with more than twice the mass of all the other planets combined, according to NASA. Its swirling clouds are also colored by different types of rare gases.
- Saturn: The sixth planet in terms of the sun, and it is known for its rings made of ice and rocks, and scientists are not yet sure of how they are formed.
- Uranus: The seventh planet from the Sun, Uranus is an eccentric. They contain clouds of hydrogen sulfide, the same chemical that makes rotten eggs smell so bad. It rotates from east to west like Venus. But unlike Venus or any other planet
- Neptune: The eighth planet from the Sun, Neptune is the size of Uranus and is known for its supersonic winds. Neptune is far from Earth and cold. The planet is more than 30 times farther from the Sun than Earth. Neptune was the first planet to be predicted using mathematics, before it was discovered visually. [٢]
dwarf planets
Celestial bodies have an orbit around the sun. It has gravity, and it has a mass that is responsible for forming spherical or elliptical shapes. Examples of dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris.
small solar system bodies
Small solar system objects are all objects in the solar system, except for planets and dwarf planets. It includes all comets, meteorites, most asteroids, near-Earth objects, and objects beyond Neptune. Examples of small solar system bodies and their definitions:
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- Asteroids: They are small solar system bodies ranging in size from planets to meteorites. The difference between them and comets is that when comets approach the sun, tails come out of them, but nothing comes out of asteroids.
- Comets: They are small solar system bodies when they approach the sun, tails emerge from them.
- meteorites: They are small solar system bodies, which are solid bodies whose sizes are larger than atoms and smaller than asteroids.
See also: The sun is not a solid body, so different parts of it rotate at different rates
Conditions for considering a celestial body as a planet
In 2006 AD, the International Astronomical Union (IAU) changed the conditions and criteria by which a celestial body was classified as a planet. Thus, the list of planets was changed, and the celestial body that did not meet the conditions was considered not a planet. And a new list of the names of the planets that fulfill the conditions, and these conditions are:
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- Every celestial body that revolves around the sun is a planet.
- It must be a massive object with considerable gravity responsible for giving it the spherical shape.
- It should also clean its orbit.
- It prevents other celestial bodies from entering its own orbit.
Why was Pluto excluded from the solar system?
The standards of Pluto do not coincide with the standards of other planets, so for many reasons it was excluded from the solar system, including:
- Its small mass does not give it enough gravity to dominate its surroundings, or to pave the way around its orbit. Pluto’s orbit is somewhat untidy.
- The orbit that Pluto takes is different from that of the other planets. All the planets in the solar system revolve around the sun in a relatively flat plane, but Pluto revolves around the sun at an angle of 17 degrees.
- From this plane, in addition, its orbit is exceptionally elliptical and intersects the orbit of Neptune.
- Also, scientists have discovered that Pluto is one of the many bodies that revolve around the sun in a region of the solar system called the Kuiper belt, and scientists believe that there are many icy and rocky bodies in this crowded region that are considered as large or larger than Pluto, and when they are discovered, scientists will have to To recognize thousands of objects as complete planets as well.
How many planets in the universe
After we got to know the number of planets in our solar system and that it consists of eight planets, we must have a question about the number of planets in the universe? To this day, scientists have no idea about the total number of these planets. And we still don’t have the technology to observe anything outside the Milky Way. We live in just one of thousands of star systems in our galaxy, the Milky Way. It is believed that the universe contains trillions of galaxies as well.
And after we answered a question How many planets in the solar system? We touched on the number of planets of the solar system according to their proximity to the sun, and we also talked briefly about the characteristics of each planet, so we have finished our article for today.