There are 8 planets in the solar system. The sun is a star, not a planet. It is at the center of the solar system. The sun gives heat and light to all the planets. The planets are always in the same order from the sun.
The planets in order:
An easy way to remember the order of the planets is:
The sun is much bigger than the planets and has a greater gravitational pull, so the planets can all move around the sun in an elliptical path. All the planets take different amounts of time to orbit the sun. For example, the Earth takes approximately 365 days to orbit the sun fully. Planets further from the sun will take longer to orbit the sun.
The is a large ball of gas (hydrogen and helium) that is constantly burning. Due to this, the sun provides light and heat.
The moon is not a planet, rather it is a small celestial body. A celestial body is essentially a natural body of rock. The Earth’s gravity keeps the moon in orbit. The moon takes approximately 28 days to orbit the Earth. Although the moon looks bright, it doesn’t actually produce light. The moon just reflects the light from the sun. The moon is spherical; however, when it is in different positions around the Earth it looks like it is different shapes. The reason for this is that the moon orbits the Earth. The sun’s rays illuminate the different parts of the moon. The Earth is a planet that orbits the sun. This is like all the other planets.
While the Earth orbits the sun, it also rotates around an imaginary line between the north and south poles called an axis. It takes around for the Earth to make a full turn on its axis. As the Earth rotates the side facing the sun receives warmth and light – this is the daytime. The side facing away from the sun will be cooler and darker – this is the nighttime . The amount of time a place spends in the light and the dark usually changes throughout the year. Generally, daytimes are longer in the summer and shorter in the winter. The axis of the Earth is not vertical, it is slightly tilted. This impacts the seasons and the amount of daylight. As the Earth is continually rotating, the sun appears to move across the sky. However, the sun is actually stationary. At sunrise, some parts of the Earth are rotating towards the sun. This makes it look like the sun is rising into the sky. At midday, the sun is at the highest point in the sky. At sunset, the same parts of the Earth are rotating away from the sun. The sun appears to be going down.
Mercury is the smallest planet that is the closest to the sun. Although it is small, Mercury is also the fastest planet in the solar system to orbit the sun. It takes 88 days for Mercury to orbit the sun. Mercury looks like the moon as it has a rocky outer surface; however, Mercury doesn’t have a moon of its own. Lastly, the temperature on Mercury is both hot and cold depending on the sunlight. The temperature is boiling hot in the sun and freezing cold in the shade.
Venus is a similar size to the Earth, however, they look very different. Venus is extremely hot and is known as the hottest planet in the solar system. Venus is also very bright, it is the brightest object in the sky after the moon and sun. Venus doesn’t have a moon of its own.
Earth is the place we call home. It is the only known planet to have living organisms. The Earth takes approximately 365 days to orbit the sun. The Earth’s surface consists of around 71% water and 29% land. Earth also has a mixture of gases such as oxygen, carbon dioxide, nitrogen, and argon which we need to survive.
The Earth has four layers. These layers include:
- Outer core
- Inner core
The crust is the thin outer layer of the Earth. It is the solid rock layer that we live on. The Earth’s crust is either continental or oceanic.
The mantle is the thickest section of the Earth. This layer is mostly made up of magma. Magma is a semi-molten rock.
The outer core is the layer that surrounds the inner core. It is a liquid layer made up of iron and nickel.
The inner core is right in the center of the Earth. It is the hottest part. The inner core is solid and it is made up of iron and nickel.
Mars is known as the red planet. This is because the surface material of Mars contains iron oxide which makes it appear red. Mars is smaller than Venus and Earth; however, it is larger than Mercury. It is a dusty, cold planet with a thin atmosphere. Scientists have found that Mars has two moons of its own.
Jupiter is the largest planet in the solar system. It is mostly made of gases and liquids such as hydrogen and helium. Jupiter is known to have over 60 moons. Jupiter also has 4 sets of rings around it made up of small pieces of rocks and dust.
Saturn is a unique planet as it has a system of icy rings around it. The rings surrounding Saturn are made from particles of ice, rocks, and dust. Saturn is known to have over 80 moons, all of different shapes and sizes. Therefore, it is the planet with the most number of moons.
Uranus is also a unique planet as it is tilted so much that it spins on its side, almost at a 90-degree angle. This planet also has rings around it; however, these rings are much smaller than the rings surrounding Saturn. Uranus is known to have 27 moons orbiting it. This planet is also a blue colour due to the presence of the gas methane.
Neptune is the farthest planet from the sun. Due to this, it takes Neptune a very long time to orbit the sun. Neptune also has 6 ring systems surrounding it. Similar to Uranus, Neptune is the colour blue due to the presence of the gas methane; however, it is a darker shade of blue for which the reason is not known. Neptune is known to have 14 moons orbiting it.
For a long time, Pluto was considered a planet; however, after more research, scientists have concluded that Pluto is a dwarf planet due to its small size.