Neptune represents a milestone in the history of our knowledge of the universe and in particular of the solar system, because before it was observed in the sky, its existence was predicted on paper using Newton's laws.

Having an orbit, the astronomers pointed the telescopes to the area of ​​the sky where this planet should be, and found it.

The 8th solar system planet, "deduced" from Newton's laws and later discovered in 1846, was named Neptune.

At an average distance of 30 U.A., Neptune takes 165 Earth years to complete an orbit. The rotational motion itself has a period of 16 hours, and the axis of rotation has an inclination of only 29.56º with the plane of orbit, contrary to what we saw in Uranus.

Although visibly similar to Uranus, Neptune has considerable differences. Both have approximately the same diameter and chemical composition (80% hydrogen, 19% helium and 2% methane), but Neptune is 18% more mass. And we already know how the mass of a planet is decisive in its evolution.

Neptune has 13 known moons, 6 of which were discovered by Voyager 2. Little is known about these moons, besides being small and probably made of ice.


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