29. MILKY WAY

Here a picture ,which is not simple "artificial", because it is based om an enormous quantity of measurements. So it is very "realistic" in a sense!
Our galaxy, where we live in, is called: the MILKY WAY, but is, like the sun, a good average with its diameter of 100.000 lightyear. It has a flat spiral shape, in the centre spherically thickened to a thickness of 10.000 lightyear, while the region in which our sun is found has a thickness of about 400 ly. The sun's location is at a distance of 28.000 ly from the centre of the Milky Way. The sun is orbiting that centre with a speed of 250 km/sec. Roughly 200 billion stars have been counted in our galaxy, that has also some neighbours, such as the smaller galaxies: the MAGELLANIC CLOUDS, a system that will be merged with ours in the long run and then completely integrated. In the centre of the Milky Way there is a so-called "black hole", with an very strong attractive power pulling all surrounding matter.
It seems to be rather crowded in the galaxy with so many stars, but if we calculated the average distance between two stars then it appears to be of the order of 4.4 lightyear! Accidentally it is about the distance between the sun and its nearest star: Alpha Centauri: 4.3 ly. But was is "nearest"? Flying to that star with a aeroplane, say a "Hunter" with a speed of ~1000 km/h it will take about 4 million years to arrive there!
Anyhow, also our Milky Way is astonishing empty!