Five Facts About Neptune

1. Strong Winds – Neptune has the strongest winds in the solar system, reaching speeds of more than 1931 km/h (1,200 mph), which are faster than the speed of sound!

2. Great Dark Spot – Neptune has a Great Dark Spot, a massive storm system similar to Jupiter’s Great Red Spot, but it appears to be temporary—it was gone by the time Voyager 2 passed by.

3. Very Cold – Neptune is one of the coldest planets, with average temperatures around -214°C (-353°F).

4. Moons and Rings – Neptune has 14 known moons, with the largest being Triton, which has geysers of liquid nitrogen erupting from its surface. Neptune also has 5 rings, though they are faint and made of dark material.

5. Discovered Through Mathematics – Neptune was the first planet to be discovered mathematically before it was observed through a telescope. Scientists predicted its existence based on irregularities in the orbit of Uranus, and it was observed in 1846.

Neptune was discovered mathematically in 1846 because astronomers noticed that Uranus wasn't orbiting as expected. Its motion suggested that another planet’s gravity was pulling on it. Two mathematicians, Urbain Le Verrier and John Couch Adams, independently calculated where this hidden planet should be. Le Verrier sent his predictions to an observatory in Berlin, and they found Neptune almost immediately, exactly where he said it would be. This was the first time a planet was discovered using math rather than direct observation! 

Click on any of the names below to learn more about other planets in our solar system. 

Mercury  |  Venus  |  Earth  |  Mars  |  Jupiter  |  Saturn  |  Uranus  |  Neptune  |  Dwarf Planet Pluto