https://www.esa.int/Science_Exploration/Space_Science/Rosetta/Where_life_began# https://www.esa.int/Science_Exploration/Space_Science/Rosett... "However, there

https://www.esa.int/Science_Exploration/Space_Science/Rosetta/Where_life_began# https://www.esa.int/Science_Exploration/Space_Science/Rosett... "However, there is now direct evidence that some of the so-called chemical ‘building blocks’ of life – organic molecules – can be found in comets."