- Date of Discovery: 23 September 1846
- Discovered By: Urbain Le Verrier, John Couch Adams, Johann Galle
- Orbit Size Around Sun
- Metric: 4,498,396,441 km
- Metric: 62,525,703,987,421 km3
- Metric: 102,410,000,000,000,000,000,000,000 kg
- Metric: 1.638 g/cm3
- By Comparison: 0.297 x Earth
Facts about Neptune
Nearly 4.5 billion kilometers (2.8 billion miles) from the Sun, Neptune orbits the Sun once every 165 years. It is invisible to the naked eye because of its extreme distance from Earth. Interestingly, the highly eccentric orbit of the dwarf planet Pluto brings Pluto inside Neptune’s orbit for a 20-year period out of every 248 Earth years.
Neptune has six known rings.
Neptune has 13 known moons, six of which were discovered by Voyager 2. A 14th tiny, very dim, moon was discovered in 2013 and awaits official recognition. Triton, Neptune’s largest moon, orbits the planet in the opposite direction compared with the rest of the moons, suggesting that it may have been captured by Neptune in the distant past.
How many missions have visited Neptune?
Just one: Voyager 2 in 1989.
How long is a day on Neptune?
One day on Neptune takes about 16 hours.
Does Neptune have rings?
Yes, Neptune has six rings.
Does Neptune have a magnetic Field?
Yes, it is about 27 times more powerful than Earth’s magnetic field.