Astrobiology not only investigates how early life took hold of our planet but also life on other planets - both in our Solar System and beyond - and their potential for habitability. The book take readers from the scars on planetary surfaces made by space rocks to the history of the Solar System narrated by those space rocks as well as exoplanets in other planetary systems. But the true question is how life arose here or elsewhere. Modern comparative genomics has revealed that Darwin was correct; a set of highly conserved genes and cellular functions indicate that all life is related by common ancestry. The Last Universal Common Ancestor or LUCA sits at the base of the Tree of Life. However, once that life took hold, it started to diversify and form complex microbial communities that are known as microbial mats and stromatolites. Due to their long evolutionary history and abundance on modern Earth, research on the biological, chemical and geological processes of stromatolite formation has provided important insights into the field of astrobiology. Many of these microbialite-containing ecosystems have been used as models for astrobiology, and NASA mission analogs including Shark Bay, Pavilion and Kelly Lakes. Modern microbialites represent natural laboratories to study primordial ecosystems and provide proxies for how life could evolve on other planets. However, few viral metagenomic studies (i.e., viromes) have been conducted in microbialites, which are not only an important part of the community but also mirror its biodiversity.
This book focuses on particularly interesting sites such as Andean lake microbialites, a proxy of early life since they are characterized by very high UV light, while Alchichica and Bacalar lakes are characterized by high-salt and oligotrophic waters that nurture stromatolites. However, it is only the oasis of Cuatro Ciénegas Basin in México that stored past life in its marine sediments of the Sierra de San Marcos. This particular Sierra has a magmatic pouch that moves the deep aquifer to the surface in a cycle of sun drenched life and back to the depths of the magmatic life in an ancient cycle that now is broken by the overexploitation of the surface water as well as the deep aquifer in order to irrigate alfalfa in the desert. The anthropocene, the era of human folly, is killing this unique time machine and with it the memory of the planet.

Valeria Souza has a bachelor's degree in Biology, master's degree in Genetics and PhD in Ecology from the National Autonomous University of Mexico (UNAM). In 1990 Valeria worked with Rich Lenski at Irvine California (UCI), where she gained experience in experimental evolution. In 1993, she took on a research position at UNAM in Mexico, where she still works today. She was one of the first researchers worldwide to study the evolutionary ecology of microbes. In 1999, Valeria and Dr. Eguiarte were invited by NASA to explore a new world on an expedition that led them to study microbial biodiversity in an unlikely oasis in the Chihuahuan desert. She is an international honorary member of the American Academy of Arts and Sciences.
Antígona Segura has a bachelor's degree in Physics, a master's in Astronomy and a PhD in Earth Sciences. She was a postdoctoral researcher at the Penn State Astrobiology Research Center and the Jet Propulsion Laboratory/California, where she worked with the Virtual Planetary Laboratory (VPL) led by Dr. Victoria Meadows. She is now a researcher at the Instituto de Ciencias Nucleares at the Universidad Nacional Autónoma de México. Her research focuses on understanding the habitability potential of rocky planets around low mass stars (red dwarfs).
Jamie S. Foster is a Professor at the University of Florida Space Life Science Laboratory. Her research interests are astrobiology, microbial ecology, and host-microbe interactions during spaceflight. Her current research activities include examining the processes by which biological ec