Neptune is the eighth and most distant planet in our solar system, orbiting the Sun at an average distance of about 2.8 billion miles (4.5 billion kilometers), which is approximately 30 astronomical units (AU). One astronomical unit is the average distance from the Earth to the Sun. Because Neptune's orbit is slightly elliptical, its distance from the Sun varies between about 2.77 billion miles (4.46 billion km) at perihelion (closest point) and about 2.82 billion miles (4.54 billion km) at aphelion (farthest point)
. To put it simply:
- Average distance: ~2.8 billion miles (4.5 billion km), ~30 AU
- Closest distance (perihelion): ~2.77 billion miles (4.46 billion km)
- Farthest distance (aphelion): ~2.82 billion miles (4.54 billion km)
At this distance, sunlight takes about 4 hours to reach Neptune, and the sunlight intensity there is roughly 900 times weaker than on Earth
