Summer on Uranus lasts for 21 years.
358
There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
Jupiter has radio storms so strong that they can be picked up and heard by an AM radio.
16
The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
219
There are 5 to 10 times more stars in the known Universe than there are grains of sand on all the world's beaches, but a single grain of sand has more atoms than there are stars in the known Universe.
20
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Earth is the only planet in our solar system that's not named after a god or goddess.
17