Science relies on signs of water to tell a story of how a celestial body or its region came to be. Now it appears our own solar system holds water older than itself, which could have dramatic consequences for our search for alien life.
To explain this new theory, a previously long-held conception of star formation needs to be examined.
Each star is forged from materials found in its own interstellar molecular cloud.
It also surrounds it with a protoplanetary disk, or a solar nebula – a belt from which its planets are born. Previous research was uncertain whether the ice in this disk comes from open space or is formed in a chemical reaction by the star’s own processes after the previous building blocks of water are evaporated.
That uncertainty is now gone and we can say that our own life is not the result of activity created within the protoplanetary disk at all.
Because water is a definitive marker of life, and because we rely on signs of it to direct our search for new habitable planets, being aware of the conditions required for its survival is a huge leap forward.