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

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).

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

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.

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

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

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.

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.

Neptune cannot support life as we know it.

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