The compounds, which include ammonia, carbon dioxide, carbon monoxide, sodium and, surprisingly, silver, could have come from the Earth, from the moon's interior, or from comets and asteroids.

Heterotrophic bacteria eat most of the carbon-based materials in raw sewage while autotrophic bacteria consume ammonia and nitrogen compounds.

Not only did it contain water, but a plethora of other compounds and elements including mercury, calcium, magnesium, carbon monoxide and dioxide, ammonia, sodium - and small traces of silver.