Earth's Precision in Life Support
In terms of supporting life, the planet Earth scores higher than any other celestial body that astronomers have ever come across. Its distance from the scorching Sun is remarkably precise. A little closer and all the water on the Earth would boil and vaporize. A little further and all the water would freeze solid. Either way, life would cease to exist.
Earth also is large enough so that its gravity is sufficient to hold an atmosphere capable of deflecting hazardous UV radiation and cosmic rays. It also serves to destroy foreign objects such as meteors and asteroids from harming the surface. It has a remarkable terrain and a rich collection of chemicals and elements.
In combination with a fortuitous climate, a beautifully balanced ecosystem can exist. In general our planet Earth is the most diverse and interesting celestial body in our universe as we know it. To date, no where else in the Universe have we found evidence of biological organisms existing in such abundance.