Nep Sli

Ten Things to Know About Neptune

1: GIANT

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

2: EIGHTH WANDERER

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).

3: SHORT DAY, LONG YEAR

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

4: ICE GIANT

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.

5: GASSY

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

6: MANY MOONS

Neptune has 13 moons (and one more awaiting confirmation of discovery), which are named after sea gods and nymphs in Greek mythology.

7: FAINT RINGS

Neptune has six known rings.

8: ONE VOYAGE THERE

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.

9: LIFELESS

Neptune cannot support life as we know it.

10: ONE COOL FACT

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