The clouds that were formed by the sun gravitational pull are our nine planets.(McDonough1) Out of the nine planets that were formed, one sticks out more than all the others. It is special in its own way. It supports life.
In order for life to exist on Earth and for extraterrestrial life to exist, humans need a constant supply of oxygen and water. The temperature needs to be favorable for the beings, not to hot to kill off life, but not to cold to halt life. Not only does the temperture need to be right for the beings, but right for food to grow for a source of energy to the beings Along with that, there needs the right atmosphere to keep strong radiation from a star to be kept out. Finally, the beings need to reproduce to continue on. These are the major conditions involved in supporting life, as we know it. .
Along with having the right conditions favorable to other intelligent beings, like ourselves, evolution of compounds and elements have to form just right to start the complex construction of life. We are uncertain if the way life started on this planet is rare or is something of the norm in other places in the universe. Some scientist believe that it would be completely impossible to have life exist elsewhere because of the complexity of the building blocks of life on Earth would be impossible to repeat itself elsewhere. They say our ancestors of evolution go back for millions of year, each predecessor having to transgress towards human beings. With that, they say the predecessors would have to fallow like or own evolution exactly, which they say is impossible, since there are to many conbinations for life. Though, Others believe that life is more abundant than we think, and life elsewhere is very possible.(Chyba1).
So if life is possible other places, where do we look? The problem with that is there are too many places to look in our universe. From our viewpoint from Earth, we can only see around a billion galaxies.
