Jun 13, 2023 00:00:00

The effect range of a supernova explosion that could cause mass extinction may be about three times larger than previously assumed

A supernova explosion is a large-scale explosion that occurs when a huge star or white dwarf ends its life. When a supernova explosion occurs, intense gamma rays are emitted to the surroundings, and it is said that life forms living on planets within 50 light years will be devastated. A study by a research team led by Ian Blanton of the University of Illinois suggested that even a supernova explosion that occurred at a distance about three times as far away as previously assumed could have a serious impact on the planet's atmosphere. .

X-Ray-luminous Supernovae: Threats to Terrestrial Biospheres - IOPscience
https://doi.org/10.3847/1538-4357/acc728

Supernova X-rays zap planets' atmospheres, 160 light-years away

https://earthsky.org/space/supernova-x-rays-planets-within-160-light-years/

In previous research, when a supernova explosion occurred, all life forms living on the surface of the planet within a radius of 5 light years were exterminated by the emitted gamma rays, half of the life forms on the planet within 25 light years were extinguished, and within 50 light years. Life on the planet was supposed to cause catastrophic damage.

But new data from NASA's

Chandra X-ray Observatory , Neil Gehrels Swift , NuSTAR , and other observations of 31 supernovae show that in the event of a supernova explosion, the X-rays emitted will produce the maximum amount of radiation. It turns out that it can seriously damage the atmosphere of a planet 160 light years away.

Quick Look: New Stellar Danger to Planets Identified by NASA's Chandra-YouTube


The emission of gamma rays from a supernova explosion subsides in a few days to a few months, but the X-rays generated when the blast from the explosion collides with a dense gas cloud are emitted over months to decades, and the shock waves are much faster than the gamma rays. reach far.

X-rays from supernova explosions can severely affect planetary atmospheres at distances of up to 160 light years. ``If the X-ray torrent hits the earth directly, most of the ozone layer will be destroyed and the ability to protect living things from harmful ultraviolet rays will be lost,'' Blanton said. ``If the ozone layer is destroyed , humans and animals will be unable to survive outside the deep sea or underground.'

However, Connor O'Mahony of the University of Illinois reports, ``So far, there are no stars near the Earth that could cause mass extinction due to X-rays.''

On the other hand, Mr. O'Mahony said, ``Earth may have been affected by supernova explosions in the past,'' and ``In the geological past of the earth, supernova explosions have occurred many times in the vicinity.'' . According to O'Mahony, a study

of radioactive isotopes of iron collected around the world suggests that a supernova explosion may have occurred about 2 million to 8 million years ago, about 65 to 600 light years away from Earth. That's what I'm talking about.

``One or more of these supernova explosions interacted to emit intense X-rays into the Earth's atmosphere, suggesting that they may have played a role in the evolution of life,'' said the research team. reporting.

In addition, it has been pointed out that such supernova explosions may shrink the habitable zone , which is the area where life similar to Earth can exist in the galaxy.

Brian Fields of the University of Illinois said, ``Further research on X-rays associated with supernova explosions may have implications not only for understanding the life cycle of stars, but also for fields such as astrobiology, paleontology, and earth and planetary science. There is.”