Neptune Facts for Kids

8th From the Sun!

Neptune is the 8th and farthest planet from the Sun in our solar system! It is so far away that it takes sunlight over 4 hours to reach Neptune. Imagine waiting 4 hours just for a ray of sunshine to arrive!

An Ice Giant!

Neptune is called an ice giant because deep inside it is made of super-hot slushy ices of water, ammonia, and methane! Even though they are called ices, they are actually boiling hot because of the incredible pressure!

The Beautiful Blue Planet!

Neptune is a gorgeous deep blue color! The methane gas in its atmosphere absorbs red light from the Sun and reflects blue light back to us. That is what gives Neptune its stunning ocean-blue look!

Fastest Winds in the Solar System!

Neptune has the fastest winds of ANY planet - they blast at over 1,200 miles per hour! That is almost twice the speed of sound! Even the most powerful hurricanes on Earth are gentle breezes compared to Neptune!

The Great Dark Spot!

When the Voyager 2 spacecraft flew past Neptune in 1989, it discovered a huge storm called the Great Dark Spot! It was as big as the entire Earth! But when the Hubble telescope looked later, the storm had disappeared and new ones had formed!

58 Earths Fit Inside!

Neptune is a giant planet - about 58 Earths could fit inside it! Its diameter is nearly 4 times wider than Earth. If Earth were the size of a nickel, Neptune would be as big as a softball!

165-Year Orbit!

Neptune takes about 165 Earth years to go around the Sun just once! That means since Neptune was discovered in 1846, it has only completed ONE full orbit! It just finished its first known trip around the Sun in 2011!

Triton: The Backwards Moon!

Neptune's biggest moon Triton orbits BACKWARDS compared to Neptune's spin! Scientists think Triton was actually a dwarf planet from the Kuiper Belt that Neptune captured with its gravity long ago!

Triton's Ice Geysers!

Triton has incredible geysers that shoot nitrogen gas 5 miles high into the sky! Even though Triton is one of the coldest places in the solar system at minus 391 degrees Fahrenheit, these geysers still erupt!

Short Days on Neptune!

Even though Neptune is huge, it spins pretty fast! One day on Neptune is only about 16 hours long. So while you would barely start your school day on Earth, Neptune would already be starting its next day!

Neptune Has Rings Too!

Neptune has a set of 5 thin rings made of dust and rock! They are much darker and harder to see than Saturn's famous rings. Scientists named them after people who studied Neptune: Galle, Le Verrier, Lassell, Arago, and Adams!

Discovered With Math!

Neptune is the only planet that was discovered using math before anyone even saw it! Scientists noticed that Uranus was wobbling in a strange way, so they calculated that another planet must be pulling on it - and when they pointed their telescope there, they found Neptune!

Only One Visitor!

Only one spacecraft has ever visited Neptune - Voyager 2 in 1989! It flew past Neptune and took amazing photos before heading out of the solar system forever. No other spacecraft has been back since!

It Rains Diamonds!

Deep inside Neptune, the pressure is so incredibly intense that it actually squeezes carbon atoms together to form diamonds! Scientists think it literally rains diamonds deep inside this planet. How cool is that!

16 Known Moons!

Neptune has 16 known moons! The biggest one is Triton, which is so large it makes up more than 99 percent of the mass orbiting Neptune. Most of the other moons are tiny and were discovered much later by powerful telescopes!

Named After the Sea God!

Neptune is named after the Roman god of the sea! With its beautiful deep blue color, it was the perfect name. In ancient mythology, Neptune ruled over the oceans with his mighty trident - a three-pronged spear!

More Heat Than It Gets!

Neptune gives off more than twice as much heat as it receives from the Sun! Scientists are still trying to figure out what is generating all that extra energy deep inside the planet. It is one of Neptune's biggest mysteries!

17 Times Heavier Than Earth!

Neptune is 17 times more massive than Earth! Even though it is not the biggest planet, it is incredibly heavy because it is packed with dense icy materials deep inside its core!

Layers of Atmosphere!

Neptune's atmosphere has beautiful layers of clouds made of methane ice crystals! The highest clouds cast shadows on the cloud deck below, just like clouds on Earth. Sometimes bright white clouds zip across the blue planet at incredible speeds!

A Tilted Magnetic Field!

Neptune's magnetic field is super weird - it is tilted 47 degrees from its spin axis and does not even go through the center of the planet! It is like if Earth's magnetic north pole was somewhere near Japan instead of the North Pole!