What is the solar system
The Solar System comprises of the Sun and all the other objects that rotate around it. These objects are bound by the Sun’s gravitational force. The Solar System includes nine planets, including Earth and five dwarf planets. Asteroids, planets, moons, comets, and planets orbiting the Solar System have their own gravity and try to get away from the Sun. The Sun, however, has a greater gravitational force than all these objects and keeps on pulling them towards it. Due to the two opposing forces the planets keep on orbiting around the Sun. The Solar System was discovered in the 17th century by Galileo.
Scientists believe that the Solar System was formed around 4.6 billion years ago when a giant cloud of gas and dust burst due to its own gravity. After the explosion, the dust and other matter in the cloud starting revolving in circular motion. Soon a star was formed at the center of the circle. The star started growing in size amassing dust and gases. Smaller bodies of gas and dust started revolving round the star, which eventually grew in size to become the Sun. the smaller bodies of gas and dust became planets, comets, moons, and asteroids.
The inner Solar System vs the outer Solar System
The Solar System is divided into two parts: inner Solar System and outer Solar System.
Inner Solar System
Inner Solar System primarily comprises of four inner planets and an asteroid belt.
Mercury: Mercury is the tiniest planet in the Solar System. It is also the closest to the Sun. Mercury does not have moons.
Venus: Venus is the hottest among nine planets. The most likely reason behind its hot climate is the large quantities of greenhouse gases found in its environment. Venus, just like Mercury, does not have any natural satellites.
Earth: Earth is the densest and the largest inner planet. Till date Earth is the only known planet to support life . Moon is Earth’s natural satellite. Earth is unique in the sense that it contains 21 percent free oxygen.
Mars: Mars’ atmosphere primarily consists of carbon dioxide. The planet’s red color is due to the vast levels of iron oxide found in its soil. Mars has two satellites.
Asteroid belt: Comprises primarily of ice and metallic minerals. Scientists believe that these objects fail to come together due to Jupiter’s gravitational force.
Outer Solar System
The outer part of the Solar System primarily comprises of four giant planets, their moons, centaurs, and comets. Due to their cold climate, these planets contain a large amount of volatiles. The four planets in the outer Solar System comprise about 99 percent of the total mass that orbits around the Sun.
Jupiter: Is the largest among none planets. The planet’s mass is around 2.5 times more than that of all the other planets put together. Jupiter has 79 known satellites.
Saturn: Is distinguished by its rings. The planet has 62 known satellites. Saturn is the only planet in the Solar System with a lesser density than that of water.
Uranus: Has less mass than all the other outer planets. Unlike other planets, Uranus orbits the Sun on its side. Till date scientists have discovered 27 satellites of Uranus.
Neptune: Neptune is denser than Uranus. One of the 14 known satellites of Neptune, Triton has a retrograde orbit, meaning that it revolves in the opposite direction to that of Neptune.
Centaurs: Are comet-like bodies. The first centaur discovered was named 2060 Chiron.
Some interesting facts about the Solar System
- Pluto’s diameter is less than that of the U.S.
- Many meteorites found in Antarctica are believed to have originated on Mars.
- Almost all elements found on Earth are rare.
- Mercury, the closest planet to the Sun is not the hottest.
- All the larger planets, and not just Saturn have rings.