About this Book
As you all might know solar system is a gravitationally bound system. It consists of the sun and all the objects that orbit it.
These objects might orbit the sun either directly or indirectly.
The eight planets are the largest objects that orbit the sun directly. Rests of them are significantly smaller objects such as dwarf planets, small solar system bodies etc. It is said that solar system was formed about 4.6 billion years ago. The reason behind such gigantic formation was gravitational collapse of an interstellar molecular cloud that has the size even bigger than our current solar system.
Most amount of the system’s mass is packed within the sun itself. A significant amount of remaining mass is contained in Jupiter. Main eight planets are often studied in two groups, inner planets and outer planets. Inner planets are mercury, Venus, Earth and Mars. These planets are often referred as terrestrial planets since their primary elements are rock and metals. Remaining outer planets are also referred as giant planets since they are noticeably massive compared to inner planets. Two largest among them that are Jupiter and Venus are known as gas giants since they are mainly formed with hydrogen and helium. Remaining two outermost planets are known as ice giants (Uranus & Neptune). These ice giants are formed with elements with high melting points compared to hydrogen and helium. These elements are called ices such as water, ammonia and methane. All planets possess their unique orbit that is almost circular. These orbits lie within a flat surface that is known as ecliptic.