Free Astronomy Magazine November-December 2014

ASTROBIOLOGY 12 NOVEMBER-DECEMBER 2014 We live on a planet full of water and it is very likely that that liquid was transferred on Earth by countless comets, along with prebiotic organic matter. But where did all that water come from? Was it formed with the planetary sys- tem or did it exist billions of years before the Sun began to shine? The answers to these questions have finally arrived. Is water o the Sun? A water droplet can be taken as a symbol of that essential element that for many bil- lions of years ac- companies the formation of plan- ets and heavily encourages the emergence of life.