When stars exploded, they formed a supernova. And the leftover supernova formed a huge cloud of gases and dust particles. If there was any other supernova explosion nearby, it sent pressure waves to this huge cloud, causing matter to clump. The clumping of matter caused the gravity between these particles to increase. And these gravitational forces intensified to cause the formation of primitive planets within the gas disk. That process is the most plausible theory of planet formation.
The eight planets in our solar system form only a small part of an arm of the Milky Way Galaxy. The sun, a star, is responsible for the forces that keep the planets aligned and orbiting around itself. Here is a look at all the eight masses that make up the solar system. You’re sure to find facts about these orbiting bodies that you never knew!
Mercury is not the hottest planet in the solar system, even though it’s the closest to the sun. Its orbit is the most eccentric among all other orbits. During orbit, its distance from the Sun changes from 46 million kilometers to 70 million kilometers, due to the elliptical orbit. Mercury orbits the fastest around the sun, completing one revolution in 87.9 earth days. It is the smallest planet in the solar system, with a diameter of 4,878 kilometers which is 2/5th of Earth’s. Its mass is about 5% of Earth’s mass. The absence of an atmosphere on the planet is the reason temperatures fall very much on some places of the planet. Mercury has a molten iron core, which is very large. This makes it the second most dense planet after Earth.
Venus is the second planet from the Sun, and closest to the Earth. It orbits the Sun at a distance of 108 million kilometers in an almost circular orbit and takes 225 Earth days to orbit. The diameter of Venus is 12,100 kilometers, very similar to the Earth’s. Its mass is 80% of the Earth’s mass, and it is the hottest planet in the solar system with a constant temperature of 460° C. Its temperature is so high due to its thick atmosphere, which is the reason Venus has the strongest greenhouse effect for any planet.
Our own planet is the largest and densest of the inner planets. Its orbit is about 150 million kilometers from the Sun, and it takes 365.25 days to complete an orbit, and it rotates around its axis once every 23 hours, 56 minutes and 4 seconds. Its axis is tilted at an angle of 23.4° to the vertical. The diameter of Earth is 12,742 kilometers. Thought to be 4.54 billion years old, Earth is the first of planets to have a moon, and the only planet to have life. The moon, with a diameter of 3,474 kilometers, and orbits Earth at a distance of about 362,000 kilometers to 405,000 kilometers. Our Earth is protected from the solar radiation by the strong magnetic field generated by its molten iron core.
The fourth planet from the Sun. Mars orbits the sun in 686 Earth days, at a distance of 230±20 million kilometers from the Sun. It also rotates around its axis in 24 hours and 37 minutes and its axis is tilted at an angle of 25.1° to the vertical. Its rotation and tilt are very similar to Earth’s and this is the reason why Mars has day and nights, and seasons like the Earth. Its diameter is 6,792 kilometers, which makes it the second smallest planet in the solar system. Mars has a very thin atmosphere, which cannot store any heat. This causes the temperatures on the planet to drop to -135° C in the winters. Mars is mainly composed of Carbon dioxide, is prone to dust storms and shows evidence of the presence of water. It also has two moons, Phobos and Deimos, and some people claim that they are just asteroids.
The largest planet in the solar system, Jupiter has a diameter of a whopping 142,984 kilometers and is 318 times more massive than the Earth. It rotates on its axis once every 9.9 hours and has an average temperature of -110°C. It orbits the sun at a distance of 740 to 817 million kilometers and takes 11.9 Earth years to complete a revolution. It is considered 75% hydrogen and 24% helium. It has about 79 satellites as of 2018, but most of these have diameters smaller than 10 kilometers. It’s four largest moons are Io, Ganymede, Europa, and Callisto. All of these were discovered by Galileo Galilei in 1610.
It has over 400 volcanoes and is geologically very active. Europa has Avery smooth surface, comprised of water ice, and there is a possibility of finding life on this moon. Ganymede is a month larger than Mercury, and has craters and ridges, with some of its surfaces covered in ice. Callisto has an atmosphere of Carbon dioxide and oxygen, along with a surface of the ice.
Saturn has a diameter of 120,536 kilometers and its mass is 95 times the Earth’s mass. It rotates on its axis once every 10.7 hours. It orbits the sun once in 29 years, at a distance of about 1440 million kilometers from the Sun. Its average temperature is -140°C. It is best known for the rings that surround it. These rings are made up of dust particles and ice. It has an amazing 62 moons, out of which only seven are large enough to be spherical in shape. Even though Saturn’s surface is cold, it’s core is quite hot, and has a temperature of 11,700°C. It is estimated to complete its rotation on its axis in 10 Hours and 39 minutes, but the exact figure is not known.
Having a mass of 86.8 yotta grams, which is about 86,800,000,000,000,000,000,000 kilograms! And even though this number looks quite large, Uranus is not the most massive planet in the solar system. Uranus has a diameter of 51,118 kilometers and has a rotation-proof of 17.2 hours. Its orbit is at a distance of about 2,750 kilometers from the sun, and it takes 84.92 years to complete an orbit. It has an axial tilt of 97.8° and has a mean temperature of -195° C. It has 27 moons and a well-known ring system.
Heavier than Uranus, it has a mass of 102 yottagrams. Its diameter of 49,528 kilometers is the reason Neptune is denser than Uranus. It is the only planet to have a gravitational field stronger than Earth’s. It completes a rotation on its axis in 16.1 hours and has an orbit of about 4,400 million kilometers from the sun. Once the Neptunian revolution takes 164.77 Earth years to complete. Having 14 known moons, Neptune is the farthest planet from the Sun, with a significant ring system!
Fiber other planets were included in the solar system before, but their size has led to being declared ‘dwarf’ planets. And even though their planets are very massive, they are not more than a tiny speck in the Milky Way, which is a very little part of the Universe. Scientists, therefore, have not able to find the end of this universe yet and are working in this direction!