This is a reprint of an entry I did for an
Abecedarium project in 2004*. I have edited it to remove the word "the" when referring to Earth (David William Fischer pointed out that no one says, "The Mars"), and to remove a sentence about exoplanets.
Earth is the only object in the Universe known to create and sustain life. Our point of view is biased: Earth is our home and mother. The size of the Universe gives us hope that there are other, similar places, that life can occur again and again. Our limitations prevent us from proving this, however. We can stand on her surface and point telescopes into the void, and we can even send small craft away from her body to transmit information back to us. Distances in space prevent us from ever visiting a planet outside of our Solar System.
How Earth created life is not understood. How she sustains life is the more important mystery. We don't really know to what degree human activity is disrupting Earth's ability to sustain us. My belief is that we may destroy Earth's ability to sustain our species (and the species that have come to depend on us) but we will never destroy her ability to sustain life itself. The important thing to know, is that if we can not live on Earth we have no where else to go.
*never did finish that abecedarium.