SIGNPOSTS TO SPACE

There are no fixed distances in space, as everything is moving. The figures given below are approximate distances. For each planet, the figure given is when the earth and planet make their nearest approach to one another. However, a rocket travelling to a planet must follow a curved path which is much longer.

From the EARTH to

PLUTO - follows an unusual path round the sun. This can bring it inside the path of Neptune, as will happen from 1969 to 2009. 

The nearest star is called Proximo Centauri, and its light takes just over four years to reach us, travelling at about 186,000 miles a second. A light-year, the unit we use to measure distances to the stars, is six million, million miles.