Reacción a "A study challenges the theory that comets played a key role in the origin of life on Earth"

This is a very interesting, high-quality article, focusing primarily on global computer simulations, numerical models, recent advances in simulations of cometary impacts and comet–atmosphere interactions, as well as on modelling the origin and evolution of comets. From the perspective of so-called ‘frontier or hybrid compounds’ between organic and inorganic matter, it focuses on HCN. It is within this specific context, combining simulations and models, that the study must be viewed.

This research does not clearly contradict existing knowledge, but it does highlight uncertainties, questions and limitations regarding the experimental evidence linked to cometary missions and numerous previous studies, based on the compositional analysis of cometary ices and on earlier simulations.

In fact, it is a study that aims, if not to refute, then certainly to challenge much of what we currently know about comets, their abundance of organic compounds and their contribution, alongside asteroids, as planetesimals relevant to the origin of life on Earth (and perhaps on other planets; Mars is mentioned, amongst others, from this astrobiological perspective).

However, there are significant limitations, not so much associated with the research carried out—on models and simulations, which I consider rigorous—but rather with its overly broad extrapolation regarding the implications of its conclusions. Furthermore, by focusing too heavily on HCN, it fails to address the astrobiological importance of water itself and of many other organic compounds present in comets. Nevertheless, in this regard, the authors themselves are cautious and state that ‘their results are not intended to rule out the significant contribution of prebiotic compounds from comets’.