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Neptune is about four times wider than Earth. If Earth were a large apple, Neptune would be the size of a basketball.

Source: NASA

Neptune orbits our Sun, a star, and is the eighth planet from the Sun at a distance of about 2.8 billion miles (4.5 billion kilometers).

Source: NASA

Neptune takes about 16 hours to rotate once (a Neptunian day), and about 165 Earth years to orbit the sun (a Neptunian year).

Source: NASA

Neptune is an ice giant. Most of its mass is a hot, dense fluid of "icy" materials – water, methane and ammonia – above a small rocky core.

Source: NASA

Neptune's atmosphere is made up mostly of molecular hydrogen, atomic helium and methane.

Source: NASA

Neptune has 14 known moons which are named after sea gods and nymphs in Greek mythology.

Source: NASA

Neptune has at least five main rings and four more ring arcs, which are clumps of dust and debris likely formed by the gravity of a nearby moon.

Source: NASA

Voyager 2 is the only spacecraft to have visited Neptune. No spacecraft has orbited this distant planet to study it at length and up close.

Source: NASA

Neptune cannot support life as we know it.

Source: NASA

Because of dwarf planet Pluto’s elliptical orbit, Pluto is sometimes closer to the Sun (and us) than Neptune is.

Source: NASA

Neptune was discovered in 1846. He became the first planet to be discovered through mathematical calculations, and not through observation. The planet's blue color is due to the presence of small amounts of methane in the outer layers of the atmosphere. However, Neptune's neighbor, Uranus, has a blue-green color in the presence of the same amount of methane. Therefore, scientists suggest that a component unknown to science is also present in the atmosphere of Neptune, which gives the planet a bluer hue. Neptune's largest moon, Triton, was discovered just 17 days after the planet's discovery.