LEARNING GUIDE · ORDER, SIZES AND DISTANCES
The eight planets of the Solar System in order
Starting from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first four are rocky; the next four are giant worlds.
THE ANSWER AT A GLANCE
Outwards from the Sun
COMPARISON TABLE
Order, distance, diameter and year length
Distances are averages: orbits are elliptical and actual distances change over time. An astronomical unit, written AU, is approximately the average Earth–Sun distance, about 150 million kilometres.
| Order | Planet | Family | Average distance | Diameter | Orbital revolution |
|---|---|---|---|---|---|
| 1 | Mercury | Rocky planet | 0.39 AU · 57.9 million km | 4,879 km | 87.97 days |
| 2 | Venus | Rocky planet | 0.72 AU · 108.2 million km | 12,104 km | 224.70 days |
| 3 | Earth | Rocky planet | 1 AU · 149.6 million km | 12,742 km | 365.256 days |
| 4 | Mars | Rocky planet | 1.52 AU · 227.9 million km | 6,779 km | 686.98 days |
| 5 | Jupiter | Gas giant | 5.20 AU · 778.5 million km | 139,820 km | 11.86 years |
| 6 | Saturn | Gas giant | 9.54 AU · 1.43 billion km | 116,460 km | 29.45 years |
| 7 | Uranus | Ice giant | 19.19 AU · 2.87 billion km | 50,724 km | 84 years |
| 8 | Neptune | Ice giant | 30.07 AU · 4.50 billion km | 49,244 km | 164.8 years |
TWO MAIN REGIONS
Rocky planets and giant planets
The four rocky planets
Mercury, Venus, Earth and Mars have solid surfaces dominated by rock and metal. They are relatively small and close to the Sun.
The main asteroid belt
This region contains many small rocky bodies and the dwarf planet Ceres. The belt's total mass is far smaller than the Moon's.
The two gas giants
Jupiter and Saturn consist mainly of hydrogen and helium. They have no solid surface on which to land.
The two ice giants
Uranus and Neptune contain larger proportions of materials such as water, ammonia and methane deep inside.
FREQUENTLY ASKED QUESTIONS
Essential answers
How many planets are there in the Solar System?
The Solar System has eight recognised planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Why is Pluto no longer the ninth planet?
Since 2006, Pluto has been classified as a dwarf planet. It orbits the Sun and is nearly round, but is not gravitationally dominant in its orbital neighbourhood.
Which planet is closest to the Sun?
Mercury is the closest planet to the Sun, at an average distance of about 58 million kilometres.
Which planet is farthest from the Sun?
Neptune is the farthest of the eight planets, at an average distance of about 4.5 billion kilometres from the Sun.
Which is the largest planet?
Jupiter is the largest and most massive planet. Its diameter is close to 140,000 kilometres, about eleven times Earth's.
Which is the hottest planet?
Venus is the hottest planet, although Mercury is closer to the Sun. Its very dense atmosphere sustains a powerful greenhouse effect and temperatures near 465 °C.
SCIENTIFIC FACT SHEETS
Explore each world
The Sun and Moon are not planets, but they are included in the atlas alongside Pluto to give a fuller picture of our neighbourhood in space.
Bodies in the 3D experience are deliberately enlarged so they remain visible. Read the scientific method to understand Artistic, Size and Distance modes, or download the printable learning resources.
SOURCES