All life on earth is made up of carbon, water and oxygen...these 3 elements are the best building blocks for life - especially carbon, because it can bond to different kind of chemicals - but silicon can replace carbon - although its less likely to bond - and ammonia for water...both are less optimal for life but are more likely than most other elements to create life... Well...what do you think...silicone based life-forms would be more like crystals.... they̢̢̮ââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢d be able to withstand higher temperatures but they're be less efficient in the way their body works...they̢̢̮ââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢d be more susceptible to our disease because their chemical makeup would be less able to cope with our germs Scientists think that if there is ''extra-terrestrial life'' that they wouldn't be too dissimela to us. they'de probably have eyes, a digestive system, motorary system (muscles) and some kind of skeletal system...although the idea of a spine would probably be unique. they would have to have some kind of hand or....grabber. Eyes would have to be the most likely because there have been many kind of eyes evolve on earth with different mechanics I believe that if the Universe is truly ̢̢̮ââ¬Å¡Ã¬Ãâ¦Ã¢â¬Åinfinite̢̢̮ââ¬Å¡Ã¬ÃâÃ