In pure state and depending on how their atoms are arranged, this element can form both the hardest mineral found in nature, the diamond and one of the softer, graphite. Organized in hexagons and forming sheets, carbon atoms give rise to graphene, a material that everyone has heard about for its “incredible” mechanical and electrical properties.
But, if this were not enough, carbon is the element on which life is based.
The chemical properties of carbon allow this element to join with a large number of different atoms to form huge and complex molecules. In fact, carbon chemistry it is so varied that it is capable of forming more chemical compounds than the rest of the elements of the periodic table together. That is why it is not surprising that there is organic chemistry, a branch of this science that is dedicated to studying only the compounds that form carbon.
On the other hand, living beings are very complex machines with bodies that need to perform a large number of tasks just for the mere fact of existing: our cells are converting sugars into energy in a constant way, deciphering and producing genetic material, transmitting information from a side by side, absorbing and processing nutrients, keeping vital systems functioning… In short, the body performs a lot of different processes at the same time, so it needs a wide variety of different chemical compounds that are compatible with each other, for to be able to carry them out.
So, as far as we know, carbon is the only element that is capable of supplying a complex organismof the chemical diversity that it needs to exist.
That’s why astrobiologists (scientists who study how life could develop elsewhere in the universe) believe that it is more likely to find intelligent life on other planets if it is based on carbon. That is, they do not simply “because they are closed minded and do not admit other possibilities”: carbon is one of the most abundant elements in the universe and is present in the planets to a greater or lesser extent, so it is reasonable to assume that Intelligent life will tend to evolve from it.
And, of course, when you have in your hands the possibility of performing an experiment whose development costs millions, you will direct your research towards the most reasonable possibility.