The Sun
Age
About 4.6 billion years
Type
Yellow dwarf star (G2V)
Diameter
1.39 million km — 109 Earths across
Share of Solar System mass
99.86%
Did you know? Every second, the Sun fuses about 600 million tonnes of hydrogen into helium — the light hitting your screen started there.
Rocky planet · 1st from the Sun
Mercury
Distance from Sun
57.9 million km
Diameter
4,879 km
Day length
58.6 Earth days
Year length
88 Earth days
Known moons
0
Average temperature
167°C average
Did you know? A single day on Mercury lasts longer than its year — and its surface swings 600°C between day and night.
Rocky planet · 2nd from the Sun
Venus
Distance from Sun
108.2 million km
Diameter
12,104 km
Day length
243 Earth days
Year length
225 Earth days
Known moons
0
Average temperature
464°C average
Did you know? The hottest planet of all — its crushing CO₂ atmosphere traps heat hot enough to melt lead. It spins backwards, too.
Rocky planet · 3rd from the Sun
Earth
Distance from Sun
149.6 million km
Diameter
12,742 km
Day length
24 hours
Year length
365.25 days
Known moons
1
Average temperature
15°C average
Did you know? The only known world with life — and the densest planet in the Solar System. 71% of its surface is ocean.
Rocky planet · 4th from the Sun
Mars
Distance from Sun
227.9 million km
Diameter
6,779 km
Day length
24.6 hours
Year length
687 Earth days
Known moons
2 (Phobos & Deimos)
Average temperature
-65°C average
Did you know? Home to Olympus Mons — a volcano 2.5× the height of Mount Everest — and Valles Marineris, a canyon as long as the USA.
Gas giant · 5th from the Sun
Jupiter
Distance from Sun
778.5 million km
Diameter
139,820 km
Day length
9.9 hours
Year length
11.9 Earth years
Known moons
95+
Average temperature
-110°C average
Did you know? The giant of the system — all other planets could fit inside it. Its Great Red Spot is a storm wider than Earth.
Gas giant · 6th from the Sun
Saturn
Distance from Sun
1,432 million km
Diameter
116,460 km
Day length
10.7 hours
Year length
29.4 Earth years
Known moons
146+
Average temperature
-140°C average
Did you know? Its rings of water ice span 280,000 km yet are often just 10 metres thick. Saturn is so light it would float in water.
Ice giant · 7th from the Sun
Uranus
Distance from Sun
2,867 million km
Diameter
50,724 km
Day length
17.2 hours
Year length
84 Earth years
Known moons
28
Average temperature
-195°C average
Did you know? Knocked onto its side by an ancient impact, Uranus rolls around the Sun at a 98° tilt — with 14-year-long seasons.
Ice giant · 8th from the Sun
Neptune
Distance from Sun
4,515 million km
Diameter
49,244 km
Day length
16.1 hours
Year length
165 Earth years
Known moons
16
Average temperature
-200°C average
Did you know? The windiest world known — supersonic gusts reach 2,100 km/h. It was found by mathematics before telescopes saw it.
Notable moons
Seven worlds that prove moons can be just as exciting as planets.
The Moon
Moon of Earth
Drifting 3.8 cm away each year, it stabilises Earth's tilt — and it is always showing us the same face.
Titan
Moon of Saturn
The only moon with a thick atmosphere — it rains liquid methane into rivers and seas.
Enceladus
Moon of Saturn
A tiny ice world spraying its buried ocean into space through geysers at its south pole.
Ganymede
Moon of Jupiter
The largest moon in the Solar System — bigger than Mercury, and the only moon with its own magnetic field.
Europa
Moon of Jupiter
Beneath its cracked ice shell hides an ocean with more water than all of Earth's oceans combined.
Io
Moon of Jupiter
The most volcanically active body known — hundreds of volcanoes erupt constantly, squeezed by Jupiter's tides.
Triton
Moon of Neptune
It orbits backwards — a captured Kuiper Belt world — and its nitrogen geysers rise 8 km high.
