Since Neptune was named for the Roman god of the sea, its moons are named for various lesser sea gods and nymphs in Greek mythology. Neptune's largest moon Triton was discovered on October 10, 1846, by William Lassell, just 17 days after Johann Gottfried Galle discovered the planet. This means that Neptune experiences seasons just like we do on Earth however, since its year is so long, each of the four seasons lasts for over 40 years.

Neptune’s axis of rotation is tilted 28 degrees with respect to the plane of its orbit around the Sun, which is similar to the axial tilts of Mars and Earth. This repeating pattern prevents close approaches of the two bodies.

Pluto can never crash into Neptune, though, because for every three laps Neptune takes around the Sun, Pluto makes two. This switch, in which Pluto is closer to the Sun than Neptune, happened most recently from 1979 to 1999. Pluto's highly eccentric, oval-shaped orbit brings it inside Neptune's orbit for a 20-year period every 248 Earth years. Sometimes Neptune is even farther from the Sun than dwarf planet Pluto. And Neptune makes a complete orbit around the Sun (a year in Neptunian time) in about 165 Earth years (60,190 Earth days). One day on Neptune takes about 16 hours (the time it takes for Neptune to rotate or spin once). Credit: NASA Visualization Technology Applications and Development (VTAD) From this distance, it takes sunlight 4 hours to travel from the Sun to Neptune.Ī 3D model of Neptune, an ice giant planet. One astronomical unit (abbreviated as AU), is the distance from the Sun to Earth. If Earth were the size of a nickel, Neptune would be about as big as a baseball.įrom an average distance of 2.8 billion miles (4.5 billion kilometers), Neptune is 30 astronomical units away from the Sun. With a radius of 15,299.4 miles (24,622 kilometers), Neptune is about four times wider than Earth. The temperatures, pressures, and materials that characterize this planet are most likely too extreme and volatile for organisms to adapt to. Neptune's environment is not conducive to life as we know it. The planet is named after the Roman god of the sea, as suggested by Le Verrier. Using predictions made by Urbain Le Verrier, Johann Galle discovered the planet in 1846. The ice giant Neptune was the first planet located through mathematical calculations. The warm light we see here on our home planet is roughly 900 times as bright as sunlight on Neptune. Neptune is so far from the Sun that high noon on the big blue planet would seem like dim twilight to us. In 2011 Neptune completed its first 165-year orbit since its discovery in 1846. More than 30 times as far from the Sun as Earth, Neptune is the only planet in our solar system not visible to the naked eye. This ring of small icy worlds is dominated by Neptune’s gravity in the same way that Jupiter dominates that of the asteroid belt thus shaping its structure.Dark, cold, and whipped by supersonic winds, ice giant Neptune is the eighth and most distant planet in our solar system. Neptune’s orbit actually has a profound impact on regions that lie directly beyond it. In fact, it has the most pronounced one in the entire Solar System. Also, since Neptune is not a solid body, its atmosphere also goes under differential rotation. Because of the fact that its axial tilt is similar to that of the Earth’s the variations in the length of its days don’t get any more extreme.

Its sidereal rotation or day lasts for about 16.11 hours a day on Neptune is equivalent to 16.11 Earth hours. However, the planet’s long orbital pretty much means that the seasons last for about forty Earth years at a time. As a result, Neptune would often experience seasonal changes that are similar to ours. Neptune’s axial tilt is 28.32 degrees, which is similar to the Earth’s tilts as well as that of Mars. Because of its 0.011 eccentricity, the distance between Neptune and the Sun often varies by around 101 million km between the perihelion and aphelion, which are the nearest and the farthest points of the planet from the Sun along its orbital path, respectively. Neptune’s elliptical orbit is inclined at 1.77 degrees when compared to our own planet. Despite this fact, it never appears in the same position in our sky because the Earth would have rotated in a different location during its 365.25 day orbit. The average distance between the Sun and Neptune is 4.55 billion km, and Neptune completes its orbit every 164.79 years a year on Neptune is 164.79 Earth years.

Neptunes days