Planet Earth :

Planet Earth :
The earth from space - the blue planet , our home . Of all the celestial bodies , only Earth is known to have all the conditions suited for life . At just the right distance from the sun , the earth has an almost circular orbit which keeps temperatures even and comfortable . We have water to drink , Oxygen to breathe , g...ravity strong enough to keep our feet on the ground but not too strong to crush us , and a million other details , all of which must be just right for us to live .
Anthropic principle states :
http://www.ideacenter.org/contentmgr/showdetails.php/id/837