How Many Planets Are There in the Solar System?
There are 8 planets in our solar system. The planets orbit the Sun in elliptical trajectories, and they are all different in size, composition, temperature, and characteristics. The planets can be grouped into two categories: the inner rocky planets and the outer gas and ice giants.
Planets of the Solar System in Order
| Rank | Planet | Average Distance from the Sun (km) |
| 1 | Mercury | 57,900,000 |
| 2 | Venus | 108,200,000 |
| 3 | Earth | 149,600,000 |
| 4 | Mars | 227,900,000 |
| 5 | Jupiter | 778,500,000 |
| 6 | Saturn | 1,434,000,000 |
| 7 | Uranus | 2,871,000,000 |
| 8 | Neptune | 4,495,000,000 |
- Mercury
Mercury is the planet closest to the Sun, and it is also the smallest planet in our solar system. Mercury does not have an atmosphere, which leads to extreme temperature changes, boiling hot during the day and freezing cold at night. Mercury has a rocky surface that is heavily cratered. Mercury is nearly the same size as Earth’s Moon. Mercury is hot because it is very close to the Sun, but it is not the hottest planet.
- Venus
Venus is the second planet from the Sun and is often called Earth’s “sister planet” because of its size and structure being very similar to that of Earth. Venus is also covered in thick clouds of carbon dioxide that hold in heat, which makes it the hottest planet in the solar system. Venus has no moons. Venus rotates very slowly in the opposite direction from most planets.
- Earth
Earth is the third planet from the Sun and the only planet known to host life. Earth is about 71% water and has an atmosphere rich in breathable oxygen. Earth has one natural satellite, the Moon; its rotation is rapid, and it has a climate which supports millions of species.
- Mars
Mars is the fourth planet from the Sun and is commonly referred to as the Red Planet. Mars is a cold, desert world, which has the tallest volcano in the solar system, Olympus Mons. Scientists think mars once had liquid water, and other missions are investigating whether Mars will support any life in the future.
- Jupiter
Jupiter is the largest planet in the solar system. It is a gas giant, with a complex atmosphere of hydrogen and helium. Jupiter has swirling storms visible from space, one of them being The Great Red Spot, which is a massive storm larger than Earth. Jupiter has at least 95 moons, and Ganymede is the biggest moon in the solar system.
- Saturn
Saturn is the sixth planet from the Sun and famous for its stunning rings made of ice, dust, and rock. Like Jupiter, Saturn is a gas giant with dozens of moons. Its largest moon, Titan, has lakes of liquid methane and a thick atmosphere. Saturn is also less dense than water—it would float if you had a big enough tub.
- Uranus
Uranus is an ice giant with a bluish-green colour caused by methane in its atmosphere. It’s unique because it rotates on its side, making its seasons extreme and unusual. Uranus is the coldest planet in the solar system and has faint rings and over two dozen moons.
- Neptune
Neptune is the farthest planet from the Sun and also an ice giant. It’s known for its deep blue colour and powerful storms. Neptune has 14 known moons, with Triton being the largest. Its winds are the fastest in the solar system, reaching over 2,000 km/h.
Why Isn’t Pluto a Planet Anymore?
Pluto was once the ninth planet, but in 2006, the International Astronomical Union reclassified it as a dwarf planet. This is because it hasn’t cleared its orbit of other objects, which is one of the three rules a celestial body must meet to be considered a planet.
Which Is The Largest Planet Of The Solar System?
Jupiter is the largest planet in the solar system. It's about 11 times wider than Earth, with an equatorial diameter of 88,846 miles (about 142,984 kilometres). Jupiter is the fifth planet from the Sun, orbiting at an average distance of 483.7 million miles (778 million kilometres).
Which Is The Smallest Planet Of The Solar System?
Mercury is the smallest planet in our solar system. Mercury is a little more than one-third the width of Earth and has an equatorial diameter of about 3,032 miles (4,880 kilometres). Mercury is the closest planet to the Sun, orbiting at an average distance of 36 million miles (58 million kilometres).
