Editing Hadean (section)

==Possible life==

Abundant Hadean-like [[Geothermal activity|geothermal]] [[Microenvironment (ecology)|microenvironment]]s were shown by Salditt ''et al.'' to have the potential to support the synthesis and replication of [[RNA]] and thus possibly the evolution of a primitive life form.<ref name = Salditt2023>{{cite journal|last1=Salditt|first1=A|last2=Karr|first2=L|last3=Salibi|first3=E|last4=Le Vay|first4=K|last5=Braun|first5=D|last6=Mutschler|first6=H|title=Ribozyme-mediated RNA synthesis and replication in a model Hadean microenvironment|journal=Nat. Commun.|date=2023-03-17|volume=14|issue=1|page=1495|doi=10.1038/s41467-023-37206-4|pmid=36932102|pmc=10023712|bibcode=2023NatCo..14.1495S}}</ref>  Porous rock systems comprising heated air-water interfaces were shown to allow [[ribozyme]]-[[Catalysis|catalyzed]] RNA replication of sense and antisense strands followed by subsequent strand dissociation, thus enabling combined synthesis, release and folding of active ribozymes.<ref name = Salditt2023/> 
A study published in 2024 inferred the [[Last universal common ancestor|last common ancestor of all current life]] to have emerged during the Hadean, between 4.09 and 4.33 Gya.<ref>{{cite journal |last1=Moody |first1=Edmund |last2=Álvarez-Carretero |first2=Sandra |last3=Mahendrarajah |first3=Tara |title=The nature of the last universal common ancestor and its impact on the early Earth system |journal=Nat. Ecol. Evol. |date=12 July 2024 |volume=8 |issue=9 |pages=1654–1666 |doi=10.1038/s41559-024-02461-1 |doi-access=free |pmid=38997462 |pmc=11383801 |bibcode=2024NatEE...8.1654M }}</ref>

Although the early part of the [[Late Heavy Bombardment]] happened during the Hadean, the impacts were frequent only on a cosmic scale, with thousands or even millions of years between each event. As Earth already had oceans, life would have been possible, but vulnerable to [[extinction event]]s caused by those impacts. The risk would not be on the frequency, but on the size of the impactor, and remains on the Moon suggest impactors bigger than the [[Chicxulub impactor]] that caused the [[Cretaceous–Paleogene extinction event|extinction of dinosaurs]]. An impactor big enough may erase all life on the planet, although some models suggest that microscopic life may still survive if underground or in the oceanic depths.<ref>{{cite book |last=Bennett |first=Jeffrey |author-link= |date=2017 |title=Life in the universe |url= |location=United States |publisher=Pearson |pages=124–125 |isbn=978-0-13-408908-9}}</ref>