Cosmic Scale
The Solar System to scale: sizes and distances of the planets
The Sun is 1,391,000 km across, 109 times wider than Earth, and holds 99.8% of the mass of the Solar System. Neptune, the farthest planet, orbits 30 times farther from the Sun than Earth does: sunlight takes 4.2 hours to reach it.
Fly through the Solar System in 3D
The planets, from the Sun outwards
| Planet | Diameter | From the Sun | Sunlight takes | Year |
|---|---|---|---|---|
| Mercury | 4,879 km | 0.39 AU | 3.2 minutes | 88 days |
| Venus | 12,100 km | 0.72 AU | 6.0 minutes | 225 days |
| Earth | 12,740 km | 1.00 AU | 8.3 minutes | 365.25 days |
| Mars | 6,779 km | 1.52 AU | 12.7 minutes | 687 days |
| Jupiter | 139,800 km | 5.20 AU | 43.3 minutes | 11.9 years |
| Saturn | 116,500 km | 9.57 AU | 79.6 minutes | 29.4 years |
| Uranus | 50,720 km | 19.2 AU | 2.7 hours | 84 years |
| Neptune | 49,240 km | 30.2 AU | 4.2 hours | 165 years |
1 AU (astronomical unit) is Earth's average distance from the Sun, 149.6 million km. See the planets in order of size.
A scale model you can walk
Shrink the Sun to a ball 1 metre wide, the size of a big exercise ball. Then:
- Mercury: a 3.5 mm ball, 41.6 m away
- Venus: a 8.7 mm ball, 77.8 m away
- Earth: a 9.2 mm ball, 108 m away
- Mars: a 4.9 mm ball, 164 m away
- Jupiter: a 10 cm ball, 560 m away
- Saturn: a 8.4 cm ball, 1.0 km away
- Uranus: a 3.6 cm ball, 2.1 km away
- Neptune: a 3.5 cm ball, 3.2 km away
The nearest other star, Proxima Centauri, would be about 28,900 km away.
Beyond Neptune lie the Kuiper belt and the dwarf planets such as Pluto and Eris, and much farther out the Oort cloud: The Oort Cloud is a vast shell of icy bodies surrounding the Solar System, so far out that passing stars can nudge its members loose.
Questions
How big is the Solar System?
Out to Neptune's orbit the Solar System is about 60 AU (9.0 × 10⁹ km) across. The Sun's wind reaches the heliopause at about 120 AU, and the Oort cloud of comets may reach a light-year or more.
What are the planets in order from the Sun?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
What are the planets in order of size?
From smallest to largest: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn and Jupiter.
Why are Solar System pictures never to scale?
Because the gaps are enormous compared with the planets. If the Sun were a 1 metre ball, Earth would be a 9.2 mm pea 108 m away, and Neptune would be 3.2 km away. A picture that shows the planets cannot show the distances.