Mars had an oxygen-rich atmosphere around 4 billion years ago
13
MDIF, a New York based non-profit organisation, is planning to beam free Wi-Fi to the entire world from space.
18
The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
13
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
A comet's tail always points away from the sun.
2
There are more nerve cells in the human brain than there are stars in the Milky Way.
349