Editing Endolith (section)

==Relationship with astrobiology==
Endolithic microorganisms have been considered a model for the search for life on other planets by inquiring about what sort of microorganisms on [[Earth]] inhabit specific [[mineral]]s, which helps to propose those lithologies as life detection targets on an extra-terrestrial surface such as [[Mars]]. Several studies have been carried out in extreme places that serve as analogs for Mars's surface and subsurface, and many studies in [[geomicrobiology]] on Earth's hot and cold deserts have been developed.<ref>{{cite journal |last1=Warren-Rhodes |first1=K. A. |last2=Rhodes |first2=K. L. |last3=Pointing |first3=S. B. |last4=Ewing |first4=S. A. |last5=Lacap |first5=D. C. |last6=Gomez-Silva |first6=B. |last7=McKay |first7=C. P. |title=Hypolithic cyanobacteria, dry limit of photosynthesis, and microbial ecology in the hyperarid Atacama Desert |journal=Microbial Ecology |date=2006 |volume=52 |issue=3 |pages=389–398 |doi=10.1007/s00248-006-9055-7|pmid=16865610 |s2cid=1914122 }}</ref> In these [[extreme environment]]s, microorganisms find protection against thermal buffering, UV radiation, and desiccation while living inside pores and fissures of minerals and rocks.<ref name="Cryptoendolithic algae of hot semia">{{cite journal |last1=Bell |first1=R. A. |title=Cryptoendolithic algae of hot semiarid lands and deserts |journal=Journal of Phycology |date=1993 |volume=29 |issue=2 |pages=133–139 |doi=10.1111/j.0022-3646.1993.00133.x|s2cid=85033484 }}</ref><ref name="Wierzchos et al. 2011"/> Life in these endolithic habitats might face similar stress due to the scarcity of water and high UV radiation that rule on modern Mars.<ref name="Academic press"/>

An excellent example of these adaptations is the non-hygroscopic but microporous translucent gypsum crusts, which are found as potential substrates that can mitigate exposure to UV radiation and desiccation and allow microbial colonization in hyper-arid deserts.<ref>{{cite journal |last1=Cockell |first1=C. |last2=Osinski |first2=G. |last3=Lee |first3=P. |title=The impact crater as a habitat: effects of impact processing of target materials |journal=Astrobiology |year=2003 |volume=3 |issue=1 |pages=3181–191 |doi=10.1089/153110703321632507|pmid=12804371 |bibcode=2003AsBio...3..181C }}</ref><ref>{{cite journal |last1=Oren |first1=A. |last2=Kühl |first2=M. |last3=Karsten |first3=U. |title=An endoevaporitic microbial mat within a gypsum crust: zonation of phototrophs, photopigments, and light penetration |journal=Marine Ecology Progress Series |date=1995 |volume=128 |pages=151–159 |doi=10.3354/meps128151|bibcode=1995MEPS..128..151O |doi-access=free }}</ref> In the same way, the ability to grow under high water stress and oligotrophic conditions confer to endolithic microorganisms to survive in conditions similar to those found on Mars. There is evidence of the past existence of water on the red planet; perhaps, these microorganisms could develop adaptations found in current deserts on the Earth. Furthermore, The endolithic structures are a good way to find ancient or current biological activity ([[biosignature]]s) on Mars or other rocky planets.