<p>The light from the sun is white and space is black.</p>
<p>When it reaches the Earth's atmosphere the light from the sun is scattered by the molecules of gas in the air.&nbsp;</p>
<p>Blue light has a shorter wavelength than other colours (except violet) and is scattered more than the other colours, making the sky appear blue.</p>
<p>There is less violet light in sunlight than blue, otherwise the sky would look purple.</p>