By rocket to Neptune: about 8.4 years
By rocket (61,000 km/h) it would take about 8.4 years to get to Neptune – at the average distance of 4.5 billion km, non-stop and in a straight line.
Because the distance keeps changing, the travel time ranges from 8 years (closest) to 8.8 years (farthest).
For comparison
Voyager 2 needed 12 years (1977–1989) because it visited Jupiter, Saturn and Uranus on the way.
How it is calculated
- Closest distance
- 4.3 billion km
- Average distance
- 4.5 billion km
- Farthest distance
- 4.69 billion km
- Speed
- 61,000 km/h (speed of the Voyager 1 probe)
- Formula
- Travel time = distance ÷ speed
- Result
- 4.5 billion km ÷ 61,000 km/h ≈ 8.4 years
Assumption: constant speed in a straight line, with no stops, acceleration or braking. Real spacecraft fly curved paths and use the gravity of planets.
Good to know: Neptune
Neptune is the outermost planet and in 1846 became the first planet found by calculation rather than by observation. It is about 30 times as far from the Sun as Earth and needs 165 years for one orbit. Only one spacecraft has ever visited it: Voyager 2 in 1989.
→ Fact sheet: NeptuneNeptune: travel time by every vehicle
| Vehicle | Speed | Travel time | Range |
|---|---|---|---|
| Car | 100 km/h | 5,100 years | 4,900 years – 5,400 years |
| Airplane | 900 km/h | 570 years | 550 years – 590 years |
| Rocket | 61,000 km/h | 8.4 years | 8 years – 8.8 years |
| Speed of light | 1,079,252,849 km/h | 4.2 hours | 4 hours – 4.3 hours |