Mungo, your mum is quite right. You and her and all of us, we are all made from the same stuff as the stars. I am not sure if this means that you should be more careful when climbing trees but it is true, and amazing.

You see, your body is made out of lots of different building blocks which are called the chemical elements. Most of your body is made out of five of them - oxygen, carbon, hydrogen, nitrogen and calcium - but there are about 55 others also involved in making you. These elements stick together in millions of different ways to form substances you know like water (which is made out of hydrogen and oxygen).

The thing is, when the universe began, only about 14,000 million years ago, there were only two of these elements, hydrogen and helium. The other elements were all put together as old stars began to die. When dying stars start to collapse they heat up very very much and new elements are created and when they die these elements are released into the universe.

If carbon and oxygen and all the rest had never been released into the universe by dying stars, there would be no carbon and oxygen and all the rest to make you. You would not be. There would be no life of any sort, not as we know it. Your mum is right - you are made out of star-dust.

So, be a wee bit careful, because what was star-dust will again be star-dust. Look after that wonderful thing which is you! And listen to your mum!