Water and Earth
 

Of all the planets, Earth is the only one with water. The water can occur because the earth has temperature and pressure conditions which make water stable.  The other planets all fail to match. Surface temperature is controlled by solar heating and by the planet’s atmosphere.  Solar heating is strongly affected by distance from the sun because the amount of energy a planet receives is affected by the inverse square law, as more and more energy misses the planet, travelling in another direction.  Earth receives enough energy to stay between 0 and 100 degrees C on average. This makes Earth receptive to living things which use liquid water.