Comets: Potential Sources of Prebiotic Molecules for the Early Earth

Why should we be interested in comets when studying the origin of life on Earth? First, comets are rich in water and carbon, two essential constituents of terrestrial life; part of Earth’s water and carbon might be of cometary origin. But comets might also have brought Earth one step further on the way to the emergence of life. Early last century, Chamberlin and Chamberlin proposed that infalling carbonaceous chondrite meteorites could have been an important source of terrestrial organic compounds (Chamberlin and Chamberlin 1908). Oro was the first in 1961 to propose from observations of carbonand nitrogen-containing radicals in cometary comae that comets may have played a similar role (Oro 1961):