Sound doesn't travel in space.
255
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Jupiter has radio storms so strong that they can be picked up and heard by an AM radio.
16
A comet's tail always points away from the sun.
2
Earth is the only planet in our solar system that's not named after a god or goddess.
17
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
Pluto is smaller than Russia.
9