المجموعة الشمسية

Near-Earth Objects are relatively small celestial bodies whose orbits revolve around the Sun

The solar system or the solar system or the solar system is the planetary system that consists of the sun and all the bodies that revolve around it, including the earth and other planets. The solar system includes other smaller objects, dwarf planets, asteroids, meteorites and comets, in addition to a thin cloud of gas and dust known as the interplanetary medium. They also revolve around the sun, but indirectly, the satellites of the planets, which are called natural satellites, or moons for short,

Of the more than 150 known moons in the solar system, most of them orbit gas giants. Two of these moons are larger than the planet Mercury.

The largest body in the solar system remains, and the most important of these bodies, of course, is the sun, the star that is located in the center of the system and is linked to its gravity, its mass is 99.9% of the mass of the entire system, and Jupiter takes the lion's share of what the sun did not take. It is the sun that radiates the light and heat that make life on Earth possible, and yet it is only a medium-sized star. After the sun comes the planets, as there are eight planets in the solar system, arranged in order of distance from the sun: Mercury, Venus, Earth, Mars (rocky planets), Jupiter, Saturn, Uranus and Neptune (the gas giants). The two larger planets, Jupiter and Saturn, are composed primarily of hydrogen and helium; While the other two planets that are farther from the sun, Uranus and Neptune, are made of materials with relatively higher melting points than hydrogen and helium. Water, ammonia, and methane are examples. All eight planets of the solar system rotate in a semi-circular path around the sun, in a plane located in an almost flat disk called the path of the solar system.

There are many solar system bodies that can be seen with the naked eye other than the sun and the moon, and among the planets these bodies are Mercury, Venus, Mars, Jupiter and Saturn, and sometimes the brightest asteroids

And transiting comets as well, in addition to meteors, where they can be seen when they enter the Earth's atmosphere and burn up, forming meteors. Of course, much more than that can be seen from the solar system's objects using the telescope.

Most astronomers currently believe that the solar system was born 4.6 billion years ago from a huge cloud of gas and dust known as the solar nebula. According to this theory, this nebula began to collapse on itself as a result of its gravity, which its internal pressure could not resist. Most of the solar nebula's material was attracted to its center, where the sun formed. It is believed that small particles of what remained of matter accumulated with a few after that, forming larger and larger bodies, until they turned into the eight planets, and what remained of them turned into moons, asteroids and comets.