Neptune is the other sub-jovian planet, along with Uranus. Superficially, Uranus and Neptune
appear similar, but there are significant differences inside. It presents a number of differences from
either Jupiter or Saturn. It is quite a bit colder and denser. The blue color of the clouds is due to the
presence of methane gas in the atmosphere. We believe there is an appreciable layer of ice within the
interior of the planet. With no layer of metallic hydrogen to generate a magnetic field, Neptune
apparently uses a layer of highly compressed water as the electrically conducting fluid.
The existence of the eighth planet was revealed to humans in the year 1846. Two men had independently
calculated the supposed planet’s position using its gravitational influence on Uranus. Who discovered Neptune? Was it
John C. Adams or Urbain Leverier? Here’s one version of the story. I guess the answer to that depends on whether you
are French or a loyal British subject. The famous physicist Richard Feynman gives this amusing twist to the story.
Although the first person to see Neptune, and know that it was a planet, was Johann Galle? Wait, did Galileo discover
Neptune?
