Why In News?
The research, published in the Proceedings of the National Academy of Sciences finds that Earth suffered an intense loss of species diversity that lasted for at least 300,000 years, possibly caused by long-lasting ozone depletion.
About:
- The explosion of a nearby star occurred at between Devonian and Carboniferous periods could have caused a mass extinction event that took place 359 million years ago.
- Hangenberg crisis- The event which led to an intense loss of species is thought to have been caused by long-lasting ozone depletion, which would have allowed much more of the Sun’s ultraviolet (UV) radiation to reach and harm life on Earth. This was called the Hangenberg crisis.
What are the Researcher’s viewpoints?
- Extensive volcanism and global warming can also rupture the ozone layer but shreds of evidence for these are indefinite as far as the time period is concerned.
- So, researchers consider that one or more supernovae explosions, at a distance of 65 light-years away from the Earth, may have caused a prolonged loss of ozone.
- Events like gamma-ray bursts, solar eruptions and meteorite collisions end up very soon. As such, they cannot pave the way for gradual ozone depletion that took place at the close of the Devonian aeon.
Theory of supernova incident:
- A supernova event can be powerful enough to bathe its galaxy in light for days and months alike. It can be spotted across the universe as well.
- Supernovae (SNe) are quick sources of ionising photons that include fatal X-rays, UV and gamma rays. Over a longer period of time, the bang clashes with the nearby gas, resulting in a shockwave that causes particle acceleration.
- As such, cosmic rays are generated by SNe. These charged particles with high energies get magnetically confined on the inside of SN remains.
- Researches propose that radioactive isotopes like plutonium-244 and samarium-146 should be discovered from the rocks and fossils dumped at the time of extinction. This, according to them, can prove the theory of supernova incident, mainly because isotopes don’t have a natural existence on Earth.
Conclusion:
- Life began on Earth some 3.5 billion years ago through a series of evolutionary changes. The recent research bounds us to think that life on Earth is not alone. In fact, it is affected by the responses of the cosmos that we all are a part of.
For more such notes, Articles, News & Views Join our Telegram Channel.
Click the link below to see the details about the UPSC –Civils courses offered by Triumph IAS. https://triumphias.com/pages-all-courses.php