Most (80% or more) of the planet’s mass is made up of a hot dense fluid of “icy” materials – water, methane, and ammonia – above a small, rocky core. Neptune is one of two ice giants in the outer solar system (the other is Uranus). Neptune’s neighbor Uranus is a blue-green color due to such atmospheric methane, but Neptune is a more vivid, brighter blue, so there must be an unknown component that causes the more intense color. Neptune’s atmosphere is made up mostly of hydrogen and helium with just a little bit of methane. With a radius of 15,299.4 miles (24,622 kilometers), Neptune is about four times wider than Earth. Of course, nothing is simple and the scientific community debated it at the time, before most settled on Neptune as the official name by the end of 1846.īecause Neptune is the god of the sea, and the planet itself is icy blue, this felt fitting to astronomers of the day. LeVerrier himself first pushed the name Neptune, but quickly reverted to naming it after himself. Galle, who had been the first to observe it with a telescope, wanted to name it after Le Verrier.

Like Uranus, we have more detailed discussions about the naming of Neptune because it was discovered less than 200 years ago. Interestingly, one of his enduring symbols was the trident, a three-pronged spear used for spear fishing. In both traditions, Neptune was also a god of horses. With Neptune, we are back to the Roman pantheon. It’s not often that the results of that test are the discovery of an entire planet in our neighborhood. Is there a more pure expression of the scientific method than that? A theory is tested and proven with a new discovery. That’s because of gravitational fluctuations, that, when they calculated it through Newtonain physics, suggested there was an undiscovered planet in the solar system.īased on these calculations made by astronomer Urbain Le Verrier, fellow stargazer Johann Gottfried Galle used the Fraunhofer telescope at the Berlin Observatory and made the first observations of the new planet, only 1 degree from its calculated position. To wit, the discovery of Neptune was the first done not by optics, but by mathematics.īasically, astronomers studied Uranus’ orbit and theorized that there must be another planet nearby. But, from time to time, it’s good to take a step back and let some things fill us with awe.

Blue planet in our solar system