The Solar System is a collection of celestial bodies consisting of a star called the Sun and all objects that are bound by its gravitational force. These objects include eight known planets with elliptical orbits, five dwarf planets\/dwarfs, 173 identified natural satellites,[b] and millions of other celestial bodies (meteors, asteroids, comets).<\/p>\n\n\n\n
Origin of the solar system<\/p>\n\n\n\n
Many hypotheses about the origin of the Solar System have been put forward by experts, some of which are:<\/p>\n\n\n\n
Nebula Hypothesis
The nebula hypothesis was first put forward by Emanuel Swedenborg (1688\u20131772)[1] in 1734 and refined by Immanuel Kant (1724\u20131804) in 1775. A similar hypothesis was also developed by Pierre Marquis de Laplace[2] independently in 1796. This hypothesis, better known as the Kant-Laplace Nebula Hypothesis, states that at an early stage, the Solar System was still a giant fog. This fog is formed from dust, ice, and a gas called a nebula, and a gaseous element that is mostly hydrogen. Its gravitational force causes the fog to shrink and rotate in a certain direction, the temperature of the fog heats up, and eventually becomes a giant star (the sun). The giant sun continued to shrink and spin faster and faster, and rings of gas and ice were ejected around the sun. Due to the force of gravity, these gases condense as their temperature decreases and form the inner and outer planets. Laplace argued that the nearly circular orbits of the planets were a consequence of their formation.<\/p>\n\n\n\n
Planetesimal Hypothesis
The planetisimal hypothesis was first put forward by Thomas C. Chamberlin and Forest R. Moulton in 1900. The planetisimal hypothesis says that our Solar System was formed as a result of other stars passing quite close to the Sun, during the early formation of the Sun. This closeness causes a bulge on the Sun’s surface, and together with the Sun’s internal processes, pulls material back and forth from the Sun. The star’s gravitational effect results in the formation of two spiral arms extending from the Sun. While most of the matter is pulled back, some will remain in orbit, cool and solidify, and become smaller objects they call planetisimals and some large ones as protoplanets. These objects collide from time to time and form planets and moons, while other remnants of matter become comets and asteroids.<\/p>\n\n\n\n
Star Tidal Hypothesis
The stellar tidal hypothesis was first put forward by James Jeans in 1917. Planets are thought to have formed due to the approach of other stars to the Sun. The near-collision caused the pulling of large amounts of matter from the Sun and other stars by their shared tidal forces, which then condensed into planets. But astronomer Harold Jeffreys in 1929 denied that such a collision was nearly impossible. Similarly astronomer Henry Norris Russell raised his objections to this hypothesis.<\/p>\n\n\n\n
Condensation Hypothesis
The condensation hypothesis was originally put forward by the Dutch astronomer G.P. Kuiper (1905\u20131973) in 1949. The condensation hypothesis explains that the Solar System was formed from a giant ball of fog that rotated to form a giant disk.<\/p>\n\n\n\n
Twin Star Hypothesis
The twin star hypothesis was originally put forward by Fred Hoyle (1915\u20132001) in 1956. The hypothesis suggests that our Solar System was once two stars of almost the same size and close together, one of which exploded leaving small fragments. The debris is trapped by the gravity of the unexploded star and begins to surround it.<\/p>\n\n\n\n
Protoplanetary Hypothesis
This theory was put forward by Carl Van Weizsaecker, G.P. Kuipper and Subrahmanyan Chandarasekar. According to the protoplanetary theory, around the sun there is a mist of gas that forms clumps that evolve gradually into solid clumps. These clumps of gas are called protoplanets.<\/p>\n\n\n\n
History of the discovery of the solar system<\/p>\n\n\n\n
At first, the Solar System was just a disk containing a cloud of hot dust and gas, the Solar Nebula. As the gas at the edge of the nebula began to cool, the starting material began to condense into solid particles rich in the elements calcium and aluminum. And when the gas then cools, the other material begins to condense. Solid particles of various types then begin to coalesce to form comets, asteroids, and planets.<\/p>\n\n\n\n
But, what really happened in the past, when the Solar System formed? At that time there were no living witnesses who could witness this historic event. However, that does not mean the formation of the Solar System has no witnesses at all. There were many witnesses who later told their stories in their own way. The rocks that fell to Earth turned out to store a myriad of stories and information from the past. One by one the mysteries were revealed. The observations and missions sent bring home stories of the Solar System’s past.<\/p>\n\n\n\n
This time, another story is revealed with the discovery of 3 asteroids which are also the 3 oldest objects in the Solar System. The evidence was obtained from observations in visible and infrared light with the telescope on Mauna Kea, Hawaii. The three ancient asteroids have not undergone significant changes since their formation about 4.55 billion years ago, and they are also much older than the oldest meteorites ever found on Earth. The results of the identification of these three asteroids indicate that they have never been found before, with a time scale of formation in the early period of the formation of the Solar System. Therefore, it would be very interesting to place these three asteroids as candidates for future space missions. It is hoped that the mission will be able to collect and bring samples from the asteroid back to Earth for research. In this way, we will be able to further understand the process of the formation of the Solar System in the first few million years.<\/p>\n\n\n\n
Solar system structure<\/p>\n\n\n\n
The Solar System is a collection of celestial bodies consisting of a star called the Sun and all objects that are bound by its gravitational force. The Solar System is divided into the Sun, the four inner planets, the asteroid belt, the four outer planets, and in the outermost part is the Kuiper Belt and scattered disk.<\/p>\n\r\n