Which planet is named after the Roman god of the sea?

Which planet is named after the Roman god of the sea? Neptune is the planet named for that Roman deity.

In Roman religion, Neptune was associated with freshwater and the sea, and he was later closely identified with the Greek god Poseidon. The planet received his name because its deep blue appearance reminded astronomers of the sea. Neptune was discovered in 1846 after mathematical predictions showed that Uranus was being gravitationally disturbed by an unseen planet.

Neptune is the eighth and most distant recognized planet from the Sun. It is an ice giant, with an atmosphere dominated by hydrogen, helium, and methane; methane absorbs red light and helps produce its blue color. Its largest moon, Triton, travels in a retrograde orbit, suggesting it was captured rather than formed alongside Neptune.

A common mix-up is confusing Neptune with Poseidon: Poseidon is the Greek counterpart, while Neptune is the Roman name. The planet’s vivid blue color also does not mean it has an ocean-like surface; its atmosphere gives way to dense, hot fluid layers far below.