"Look at the Pole Star some night, and you will not see it as it is now,
but as it was more than sixty-two years ago. All this time its light
has been on its way to Planet Earth. If a planet travels around the Pole
Star, or Polaris, as it is sometimes called, and an astronomer on that
planet looked at the earth he would not see it as it is now, but as it
was more than sixty-two years ago. There are other stars so far away that
light takes hundreds of years in coming here. Perhaps they faded out
long ago, but the message is still on its way. It does seem strange to
think of people who may be living on distant worlds in space, watching
our little world, but we need not fear. The earth is so small that it
could not be seen at all, even from the nearest star. At that distance
Giant Sun would not look quite as bright as Sirius does to us, and giant
Planet Jupiter would only appear as a faint speck of light near the sun."
"How far away everything seems to be!" said Harry. "Yet you said just
now that we could tell what the stars are made of. How can we do that?"