The sun is actually a star. It appears much larger, because it is so much closer. You can try out at home by putting your thumb in front of your eyes, and comparing it to the more distant standing  mum. Mother appears the size of a thumb, because she t is further away. This phenomenon is called a perspective.

The stars are huge fireballs. Actually, they have a huge amount of gas, whose own weight to keep star together. The star is an ongoing fusion reaction, a bit like nuclear power plants. The result is an enormous amount of light, warmth and a lot of different types of invisible radiation.

After Sun the closest star is Proxima Centauri, which is about four light-years away. It is so far away that with the world’s fastest spaceship it would take more than 73 000 years to get there. It is a long time. 73 000 years ago, the cave men learned to use tools and make drawings in the cave walls. The same spacecraft would circulate around the earth in about three quarters of hour.

There is almost infinite number of stars in space. Most of them are so far away that they can not be seen with the naked eye in the night sky. There are much more stars, than there are grains of sand on the beach. Around each star may have planets such as Earth.

Stars form star clusters and galaxies. Galaxy may be hundreds of billions of stars. Galaxies tend to look helical wafer. Our galaxy, the Milky Way, may be visible in the night sky as a light stripe. The Milky Way is a spiral galaxy, but we see it from the inside so it appears as a stripe.

Clouds are made of water. In general, they consist of water droplets or ice crystals. As the droplets and crystals grow sufficiently heavy, they fall down as rain. Fog is a cloud that reaches the earth’s surface. The clouds are created when moist air rises it cools and condenses into very small droplets or ice crystals.

Clouds cool the planet by reflecting solar radiation back into space. On the other hand they have a warming effect in the winter also prevents the heat escaping from the Earth’s surface.

In addition to the regulation of the temperature, the clouds are vital for plants and animals, as they carry water from the rivers and the wetter regions to drier regions. If there were no clouds, it would not rain water and many plants die from drought. Then there would be no food for the animals.

In deserted lands it is usually not raining. They are dead spots, in which only species that can survive are those, that specialize in surviving such hostile environments.

“Where does man come from” -article talked about Charles Darwin and evolutionary theory.  When animals get babies, they are all different. Then, when these babies grow to adulthood and have their own offspring, some of their properties inherited by their descendants.

Animal breeding means that you look for certain properties in animals, and pick those to reproduce. When you keep doing this over decades, all of that species share the same properties. Take always hens that lay largest eggs and little by little, all the eggs of all hens will be larger.

The dog has been bred from wolf. People have domesticated wolves as their pets and most well behaving ones made puppies together and this went on over and over again. This way the current dog breeds were born.

At first one might say that it has always been there. However, scientists have discovered that space is expanding all the time, like a balloon. Strangely it seems like all points in space move farther apart all the time. You can try drawing points on an empty balloon with a marker and then ask your dad to inflate it  carefully. You will notice that the points move away from each other when the ball grows bigger.

By calculating backwards it was thought that sometimes, some 14 billion years ago, all material in the universe was one hot and dense mass. Much hotter than the sun. Then came a huge explosion which threw stuff around and at the same moment space and time were created. Little by little material got colder and began to form elements, which formed molecules which, while colliding, began little by little to form clouds, which are then condensed into stars and planets over billions of years.