Editing Extinction event (section)

==== A nearby nova, supernova or gamma ray burst ====
A nearby [[gamma-ray burst]] (less than 6000 [[light-year]]s away) would be powerful enough to destroy the Earth's [[ozone layer]], leaving organisms vulnerable to [[Ultraviolet|ultraviolet radiation]] from the Sun.<ref name="20 ways">{{cite web | vauthors = Powell CS |author-link=Corey S. Powell |date=2001-10-01 |title=20 Ways the World Could End |url=http://discovermagazine.com/2000/oct/featworld/article_view?b_start:int=0&-C= |access-date=2011-03-29 |publisher=Discover Magazine}}</ref> Gamma ray bursts are fairly rare, occurring only a few times in a given galaxy per million years.<ref>{{cite journal | vauthors = Podsiadlowski P, Mazzali PA, Nomoto K, Lazzati D, Cappellaro E |year=2004 |title=The Rates of Hypernovae and Gamma-Ray Bursts: Implications for Their Progenitors |journal=[[Astrophysical Journal Letters]] |volume=607 |issue=1 |page=L17 |arxiv=astro-ph/0403399 |bibcode=2004ApJ...607L..17P |doi=10.1086/421347 |s2cid=119407415}}</ref>
It has been suggested that a gamma ray burst caused the [[Ordovician–Silurian extinction events|End-Ordovician]] extinction,<ref>{{cite journal |last1=Melott |first1=Adrian L. |last2=Lieberman |first2=B. S. |last3=Laird |first3=Claude M. |last4= Martin |first4=L. D. |last5=Medvedev |first5=M. V. |last6=Thomas |first6=Brian C. |last7=Cannizzo |first7=John K. |last8=Gehrels |first8=Neil |last9=Jackman |first9=Charles H. |url=https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/abs/did-a-gammaray-burst-initiate-the-late-ordovician-mass-extinction/F37A58C811EB82496CEF6CF989159807 |title=Did a gamma-ray burst initiate the late Ordovician mass extinction? |journal=International Journal of Astrobiology |date=5 August 2004 |volume=3 | issue=2 | pages=55–61 |arxiv=astro-ph/0309415 |doi=10.1017/S1473550404001910 |bibcode=2004IJAsB...3...55M |hdl=1808/9204 |s2cid=13124815 |access-date=27 December 2022}}</ref><ref name="Melott & Thomas 2009">{{cite journal | vauthors = Melott AL, Thomas BC |year=2009 |title=Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage |journal=Paleobiology |volume=35 |issue=3 |pages=311–20 |arxiv=0809.0899 |doi=10.1666/0094-8373-35.3.311 |bibcode=2009Pbio...35..311M |s2cid=11942132}}</ref> while a supernova has been proposed as the cause of the [[Hangenberg event]].<ref>{{Cite journal|last1=Fields|first1=Brian D.|last2=Melott|first2=Adrian L.|last3=Ellis|first3=John|last4=Ertel|first4=Adrienne F.|last5=Fry|first5=Brian J.|last6=Lieberman|first6=Bruce S.|last7=Liu|first7=Zhenghai|last8=Miller|first8=Jesse A.|last9=Thomas|first9=Brian C.|date=2020-09-01|title=Supernova triggers for end-Devonian extinctions|journal= Proceedings of the National Academy of Sciences|language=en|volume=117|issue=35|pages=21008–21010|doi=10.1073/pnas.2013774117| arxiv=2007.01887|issn=0027-8424|pmid=32817482|pmc=7474607|bibcode=2020PNAS..11721008F |doi-access=free }}</ref> A supernova within 25 light-years would strip Earth of its atmosphere. Today there is in the Solar System's neighbourhood no critical star capable to produce a supernova dangerous to life on Earth.<ref name="ESO Supernova Exhibition f453">{{cite web | title=ESO Supernova | website=ESO Supernova Exhibition | url=https://supernova.eso.org/exhibition/1218/#:~:text=If%20a%20supernova%20explosion%20were,there's%20no%20reason%20to%20worry. | access-date=2024-04-08}}</ref>