This was a very popular question even before the first man made satellites went into orbit. Now we are planning to go into space and this makes us still more curious about the heavens. We learn that some stars are billions of miles away and beyond them are more stars. Naturally, we stretch out our minds and ask where it all ends. If we get an answer, we stop stretching and turn our minds to learning what science has so far found out about the Universe.

A rocket traveling at 1,000 miles an hour could reach the moon in about ten days and the sun in about a year, The Solar System is more than 7,000 million miles from side to side and the nearest star to our sun is about 26 million, million miles out in space. Some of the stars in our sky are many billions of miles away, yet we can see only a small corner of the great Galaxy of stars called the Milky Way,

This vast system of stars is shaped somewhat like a pinwheel and from orr little earth we can gaze out across it. We see the Milky Way as a pale arch of hazy light looping over the night sky. It is made of billions of brilliant suns, so far away that their light blurs and dims to a ghostly haze.

We measure the Milky Way by the speed of light which travels about six million, million miles in a year, or about 186,000 miles a second. Six followed by 12 zeros is the number of miles in a light year   and our Milky Way Galaxy is about 80,00() light years from side to side. Our bitsy Solar System is about 26,000 light years from the center of the starry wheel.

The Milky Way is called an Island Universe, for it is surrounded by vast oceans of empty space, But this is not the end of the Universe. Some 75,000 light

Some 75,000 light years from the Milky Way we have a sister Island Universe, bigger than our own. Within 250 million light years of the sun there are 25 similar star systems. Our telescopes have probed 1,000 million light years in all directions and in this vast space there are perhaps 100 million Island Universes.

The real Universe includes our world, our Solar System, our Island Universe and all its sisters. It includes countless Island Universes and all the vast oceans of space between them. Our minds cannot even imagine the end of the real Universe. If someone claimed to reach it, we would ask what is on the other side   and this too would be part of the Universe.

Our minds cannot imagine a limit to the Universe which includes everything. But our telescopes are probing deeper and deeper into outer space and the count of all the newly discovered galaxies is still being made, They seem to be speeding away from each other and our present knowledge indicates that the vast Universe is expanding. This is another mystery of the Universe which we cannot explain,