The dimensions of the universe are unimaginable. Can we speak in km for the solar system, even when it is in the millions, in cosmic sense this is totally useless. That is why astronomers are measuring distance in "light-years". One light-year is the distance that light (and other forms of electromagnetic radiance) can travel in one year with its speed of 300.000 km per sec. This is 100.000.000.000.000.km (hundred thousand billion km). Earth is 8 to 10 light-minutes away from the sun. Neptune is about 4 light hours away but the closest star next to our sun is approximately 10 light-years away. Our galaxy measures 100.000 light-years across. The light and other radiation from the most distant parts of the universe has traveled for 15 billion years before it reached our telescopes and listening devices. That is a distance of 1500.000.000.000.000.000.000.000.000 km……………

How did this come into being? Most astronomers nowadays think that the universe started in a split second of zero time, space and matter. They call this THE BIG BANG THEORY. They have many arguments for this, all based on observations and difficult calculations. One of the discoveries was, that all galaxies are moving apart form each other with great speed. This process of expansion (or explosion) is going on for about 15.000.000.000 years. In this time span countless stars have been born and dying. The resulting stardust was molded into new stars, planets, planetoids, comets and meteorites by cosmic forces. In fact we ourselves are made of this billions of years old stardust.