Our solar system

The Sun

sol

What do you see when you look up into the night sky? Do you ever see stars? Let’s start at the most important star in your life: the Sun.

That’s right; the Sun is a star too! It is very hot, and a lot bigger than Earth. All of the planets in our solar system travel around it! We believe that the Sun formed about 5 billion years ago. By mass it is 71% hydrogen and 27% helium. 

Why is the Sun important?

  • It provides the Earth with energy. If there was no Sun there would be no life on Earth
  • It keeps us warm
  • It defines the seasons
  • The light produced tells us and animals when to sleep

Learn about the Sun's surface with this video...

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Rocky Planets

The rocky planets, from left to right: Mercury, Venus, Earth, Mars

Mercury

Mercury is the closest planet to the Sun. It is very small and it has no moons. The entire planet is only slightly bigger than our Moon. It is made out of rock and it has not changed much since it was first formed. If we look at the surface of the planet we see a lot of craters, formed from asteroids hitting the planet!

  • Diameter: 3032.4 miles / 4880 km
  • Distance from earth: 36 million miles (57.9 million km)
  • Orbit around the sun: 88 Earth days
  • One Rotation: 59 Earth days
  • Moons: 0
  • Rings: 0
  • Your Weight: if you weigh 100 pounds on Earth, you would weigh 38 pounds on Mercury

Venus

Venus is the next furthest from the Sun. It is very similar in size to Earth. Have you ever heard about the greenhouse effect? It is currently causing our planet to warm up more than usual. This happened on Venus too. Venus had a lot of carbon dioxide in its atmosphere (a lot more than we do) and all the heat from the Sun got trapped under a thick layer of clouds. Because the heat has nowhere to go, Venus gets hotter and stays hot!

  • Diameter: 7520 miles / 12,100 km
  • Distance from sun: 67.24 million miles / 108.2 million km
  • Orbit around the sun: 225 Earth days
  • One Rotation: 243 Earth days
  • Moons: 0
  • Rings: 0
  • Your Weight: if you weigh 100 pounds on Earth, you would weigh 91 pounds on Venus

Earth

Earth is next to Venus. Our planet is very unique because it is the only one known to be able to support life.

  • Diameter: 7926.2 miles / 12,756 km
  • Distance from sun: 92.9 million miles / 149.6 million km
  • Orbit around the sun: 365.2 Earth days
  • One Rotation: 1 Earth day
  • Moons: 1
  • Rings: 0
  • Your weight: Your weight on Earth is the same

Mars

Mars sits next to Earth. There is little water on Mars at this time, but we think that it used to have large lakes or even oceans on it! Mars has two tiny moons which orbit close to it.

  • Diameter: 4,194 miles / 6,794 km
  • Distance from sun: 141.71 million miles / 227.9 million km
  • Orbit around the sun: 687 Earth days
  • One Rotation: almost 1 Earth day
  • Moons: 2
  • Rings: 0
  • Your weight: if you weigh 100 pounds on Earth, you would weigh 38 pounds on Mars

Gaseous Planets

Jupiter
Saturn
Uranus
Neptune

The gaseous planets, from left to right: Jupiter, Saturn, Uranus, Neptune

Jupiter

Jupiter is the biggest planet. It is made up of 90% hydrogen, and 10% helium. Jupiter is well known for its “red spot” which can be seen from space. It is believed that this red spot is an ancient storm of swirling winds which has lasted now for hundreds of years. The red spot is big enough to hold two Earths!

  • Diameter: 88,736 miles / 142,800 km
  • Distance from sun: 483.88 million miles / 778.3 million km
  • Orbit around the sun: 12 Earth years
  • One Rotation: 9 hours, 55 minutes
  • Moons: 79
  • Rings: 4
  • Your weight: if you weigh 100 pounds on Earth, you would weigh 265 pounds on Jupiter

Saturn

Saturn is smaller than Jupiter, but still much larger than Earth. Saturn is well known for its rings, which are made up of small particles (rocks, ice, water and gases) circling the planet.

  • Diameter: 74,978 miles / 120,668 km
  • Distance from sun: 887.14 billion miles / 1,427 billion km
  • Orbit around the sun: 29 ½ Earth years
  • One Rotation: 10 hours, 40 minutes, 24 seconds
  • Moons: 53-82
  • Rings: 7
  • Your weight: if you weigh 100 pounds on Earth, you would weigh 108 pounds on Saturn

Uranus

Uranus appears blue because its upper atmosphere is made up of methane. The planet has coloured bands, but they are hidden. Uranus spins differently than the other planets, it spins sideways!

  • Diameter: 32,193 miles / 51,810 km
  • Distance from sun: 1,784 billion miles / 2,870 billion km
  • Orbit around the sun: 84 Earth years
  • One Rotation: 17 hours
  • Moons: 27
  • Rings: 11
  • Your weight: if you weigh 100 pounds on Earth, you would weigh 86 pounds on Uranus

Neptune

Neptune is also blue because of the methane gas in its atmosphere. It also has the fastest winds of any other planet (recorded winds of 2000 km/s)!

  • Diameter: 30,775 miles / 49,528 km
  • Distance from sun: 2,769.46 billion miles / 4,497 billion km
  • Orbit around the sun: 687 days
  • One Rotation: 16 hours and 7 minutes
  • Moons: 14
  • Rings: 4
  • Your weight: if you weigh 100 pounds on Earth, you would weigh 114 pounds on Neptune

Dwarf Planet

pluto

Pluto is now a dwarf planet because of its size and location

Pluto

Pluto has been our favourite dwarf planet since 2006. It appears to spin on its side, with its equator pointing up and down and the poles pointing to either side. Pluto is by far, smaller than any of the planets. It has five moons orbiting it. A NASA spacecraft took images of Pluto for the first time in 2015, 5 billion kilometres from Earth, and captured surprising features like young mountain ranges!

  • Diameter: 1,423 miles / 2,290 km
  • Distance from sun: 3.666 billion miles / 5,900 billion km
  • Orbit around the sun: 248 Earth years
  • One Rotation: 6 days, 9 hours, 18 minutes
  • Moons: 5
  • Rings: ?
  • Your weight: if you weigh 100 pounds on Earth, you would weigh 7 pounds on Pluto