The solar system consists of eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, and Uranus.While Mercury is the closest to the Sun, Uranus is the farthest planet graced with very little sunlight due to the greater distance from the Sun. With different distances from the Sun, the planets’ atmospheres also change.The whole of the solar system can be divided into two groups; the inner planets close to the Sun; and the outer planets that are farther from the Sun. Then, other celestial bodies like moons, dwarf planets, asteroids, and comets form the entire solar system. Hydrogen, helium, and carbon dioxide are abundant elements in space.Here are some of the most important facts related to inner planets and outer planets.Inner PlanetsThe inner planets consist of Mercury, Venus, Earth, and Mars, as these four are the closest to the Sun.As these planets are closer to the Sun, they have smaller orbits than those farther away.Even the planets are smaller compared to the gas giants and have no rings surrounding them.Mercury is the closest planet to the Sun, with a diameter of 1,516 mi (2,439 km). Mercury has a thin atmosphere that contains oxygen, hydrogen, helium, sodium, and potassium. The extreme proximity to the Sun means that life can not thrive on Mercury. There is no moon orbiting the planet Mercury.Venus is the twin planet of Earth and the second planet from the Sun. The diameter of Venus is 3,760 mi (6,051 km) which is quite close to that of the Earth at 3,963 mi (6,377 km). Venus can not support life either due to its toxic thick atmosphere and scorching temperatures on the surface. It has a thick, poisonous atmosphere filled with carbon dioxide, and no moon orbits the planet Venus.The only known planet in space to harbor life is Earth. Earth is the third planet from the Sun, with the atmosphere primarily comprising nitrogen and oxygen, but no rings orbit the Earth. Earth is also the only planet with liquid water on the surface. Earth has one of the most stable atmospheres in the solar system. The moon orbiting Earth is the largest in terms of the size of the host planet.Mars is the fourth planet from the Sun and the last inner planet on this side of the Asteroid Belt.Outer PlanetsThe planets farther away from the Sun in the solar system are called outer planets or jovial planets.They are Jupiter, Saturn, Neptune, and Uranus and have orbits that are pretty large compared to the inner or terrestrial planets.They are generally composed of hydrogen and helium gases, are often referred to as the gas giants, and are much larger than the inner planets.The elements forming these planets are similar to the elements of the Sun. While this is true, the gases helium and hydrogen being lighter escaped the atmosphere of these planets due to low gravitational forces.Jupiter is the largest planet in the solar system and is entirely composed of Hydrogen and Helium. Jupiter is also known as the vacuum of the solar system and keeps the space around Earth safe from various rogue asteroids. Jupiter has a faint ring system around it. The atmosphere of Jupiter is quite violent, with numerous storms present at all times. After the Sun, Jupiter is the largest body in the solar system. Astronomers from the Earth can observe Jupiter using a good land-based telescope.Saturn is the neighbor of Jupiter and the second-largest planet in the solar system. Saturn has the highest number of moons in the solar system and a low density due to the presence of lighter elements in its atmosphere. The ring system of Saturn is its most outstanding feature. Astronomers can easily identify Saturn in the night sky. Saturn is the lightest of the outer planets. The atmosphere features hydrogen, helium, and methane.Uranus is an ice giant which is the neighbor of Saturn. It has planetary rings like Saturn, but they are very faint. Uranus experiences the weirdest tilt around its axis and has a magnetic field that defies standard physics. Its atmosphere is primarily composed of hydrogen, helium, and methane.Neptune is the outermost planet of the solar system discovered by William Herschel, one of the most famous astronomers. Like the atmospheres of most outer planets, this ice giant has an atmosphere featuring hydrogen, helium, and methane. Neptune features six very faint rings.The Asteroid BeltThis can be considered the border dividing the terrestrial planets from the jovial planets as it is found roughly between Mars and Jupiter. As the name suggests, this belt is made up of asteroids, dust, and dwarf planets. All the particles in the asteroid belt also circle the Sun; while some remain in this belt due to the gravity of the planets, some are pushed out of the solar system as well.Let’s look at some of the crucial points of this asteroid belt.Most of the belt consists of four major objects, Ceres, a dwarf planet, and Vesta, Pallas, and Hygiea, asteroids.While there are thousands of asteroids in this belt, the biggest is Ceres which earned it the title of a dwarf planet.As this belt is between planets Mars and Jupiter, the shape of this belt is in a disc form and was discovered in the year 1801.The asteroids consisting of this belt are made up of rocks and metals which are irregular in shape.These asteroids can be thrown out of the belt in outer space and can also be pulled towards a planet due to gravitational attractions.This asteroid belt can sometimes be called the central belt to avoid confusion between it and some groups of asteroids found in the solar system.Three Major Characteristics Of The Inner PlanetsThere might be something common to all the solar system’s terrestrial planets. These can be termed as the characteristics that make them similar. Though all the planets in the solar system are different and have different properties, these similarities between the first four planets make them part of the inner planets.The first character will be their rocky core. All the planets have iron in their core and have no ring systems.The next characteristic is that of solid surfaces. All four planets share the same type of rocky surface.The orbits for inner planets are smaller, and the rotation speed is also slow as these planets are closer to the Sun’s gravitational influence.Similarities Between The Terrestrial And Jovian PlanetsAfter talking about the inner planets and the outer planets, there are some similarities between the two. Though the similarities are not many, the differences are more than compared to the similarities. Here, under this section, we will discuss those similarities we talked about.Both these types of planets revolve around the Sun on their fixed orbits.Both types of planets have moons as their natural satellite.The shape will be the next similarity; they are both spherical.Both the types, inner and outer, have four planets in each category.And lastly, both together consists of the solar system.Difference Between Inner And Outer PlanetsAs we talked about them, it’s time to look at their differences. These differences are the reason which divides them into outer and inner planets. Let us sum them up:Inner planets are closer, while the outer planets are farther away from the Sun.While terrestrial planets are smaller in size, the jovial planets are quite bigger in comparison.The composition of the inner planet is that of a rockier surface. The outer planets are primarily composed of gases.The surface of the inner planets is solid, while this is not the case with inner planets, which have gaseous balls as their surface.Inner planets have no rings around the planets, while the outer planets do have them.The inner planets have different atmospheric compositions, while the inner planets share a similar atmosphere.The density of the inner planets is higher than compared to the outer planets.The inner planets’ orbiting rate is faster than the outer planets.While an asteroid belt marks the end of the inner planets, this belt acts as the starting point of the outer planets.Finally, the spinning rate of the outer planets is much slower than that of the inner planets.
The solar system consists of eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, and Uranus.
