Warming Ourselves by the Fire!
This artist's impression (albeit the sun is too large on a realistic scale) emphasises the fragile nature of our existence in the Cosmos.
Key Facts and Ideas
The nearest star system beyond our own is over 4 light years away (Centauri), some 7000 times further distant than from earth to the edge of our own system. In a very real sense, we warm ourselves by a "fire" that will itself last no longer than 5 billion years. There are stars in our galaxy much older than our own, usually smaller cooler furnaces that tend to last longer. The heavier more brightly burning stars last for a much shorter period of time.
Formation of the Solar System
Here we have the first constraint for the creation of life in any system. The star mustn't be too big. Next, the system itself has a fairly narrow habitable zone which can support complex life, at least as far as we recognise such life in terms of energy processing and genetic coding. Moreover, having a gas giant such as Jupiter in the outer system to mop up most of the system debris isn't a bad idea either; otherwise a continuous rain of asteroids might make life intolerable. What a blessing that we live in a system which like Goldilock's bed is "just right."
This is a local version of the so-called anthropic principle. This system seems to have been "designed for life." Yet, can this really be true? By December 2005 157 planets had been detected in other systems of our own galactic neighbourhood, but very few were in systems with conditions comparable to our own. The probable rarity of our own system profile is nonetheless balanced by the vast number of planets in our galaxy alone, in which there might be at least 10,000 "earths." We should perhaps NOT therefore be surprised that we live in a system such as this. We shall speak more of the anthropic principle proper here. It is one of the most crucial aspects in the debate raging right now over whether or not the Universe is "designed for life."
It's wonderful that life can exist in this Universe but we cannot base any significance for own own biosphere or humanity religiously speaking on the particular conditions that have made life possible here.
The 16th century philosopher Giordano Bruno speculated that "the universe is infinite, composed of many worlds and animated by common life and common cause" ... a prescient insight that didn't exactly make him very popular with the Catholic Church.
In your view, does the probable existence of many worlds and many life forms with abilities at least matching our own make it more or less likely that the Creator cares about any one species such as our own?
1. The Eight Planets by Bill Arnett
2. PlanetQuest - the search for another earth from NASA Jet Propulsion Laboratory (C.I.T.)
Your Own Questions Answered Here