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Supernovae May Explain Mass Extinctions of Marine Animals During Pliocene Era (theregister.co.uk)
"The Register has an article on the possibility that a supernova or a series of them could explain a mass die-off of marine animals around 2.6 million years ago," writes Slashdot reader KindMind. From the report: A gigantic supernova explosion may have triggered mass extinctions for creatures living in Earth's prehistoric oceans some 2.6 million years ago, according to new research published in Astrobiology. Marine animals like the megalodon [...] suddenly disappeared during the late Pliocene. Around the same time, scientists [...] noticed a peak in the iron-60 isotope in ancient seabeds. "As far back as the mid-1990s, people said, "Hey, look for iron-60. It's a telltale because there's no other way for it to get to Earth but from a supernova.' Because iron-60 is radioactive, if it was formed with the Earth it would be long gone by now. So, it had to have been rained down on us" explained Adrian Melott, lead author of the paper and a physics and astronomy professor at the University of Kansas.
The team believes that a supernova located 150 light years away set of a chain of supernovae bursts and covered the Earth in a shroud of deadly cosmic ray radiation. This was amplified, Melott said, because the Solar System is right on the edge of an area of the interstellar medium called the Local Bubble. The Local Bubble extends about 300 light years across and contains the two main clouds of dust and gas: Local Interstellar Cloud and the G-Cloud. As the supernovae ejected cosmic rays, these beams of energetic particles would have repeatedly bounced off the clouds to create a "cosmic-ray bath" that could have lasted 10,000 to 100,000 years. Some of that radiation such as cosmic ray muons would have leaked onto Earth, and over time it could have led to genetic mutations and cancers [that would have caused animals like the megalodon to die off prematurely].
The team believes that a supernova located 150 light years away set of a chain of supernovae bursts and covered the Earth in a shroud of deadly cosmic ray radiation. This was amplified, Melott said, because the Solar System is right on the edge of an area of the interstellar medium called the Local Bubble. The Local Bubble extends about 300 light years across and contains the two main clouds of dust and gas: Local Interstellar Cloud and the G-Cloud. As the supernovae ejected cosmic rays, these beams of energetic particles would have repeatedly bounced off the clouds to create a "cosmic-ray bath" that could have lasted 10,000 to 100,000 years. Some of that radiation such as cosmic ray muons would have leaked onto Earth, and over time it could have led to genetic mutations and cancers [that would have caused animals like the megalodon to die off prematurely].
BeauHD sucks as an editor
BeauHD sucks as an editor
He tells you three times the same thing... and still no inkling as to WHY that would be the case.
This is not how you write summaries, BeauHD. Thus we see that BeauHD sucks as an editor.
I like the last E.
So any evidence of dinosaur cancers, or are we just making shit up now because maybe?
There were no dinosaurs in the Pliocene (5.3 to 2.6 mya). The dinosaurs died out roughly 70 million years ago (except for birds).
The supernova hypothesis is not just conjecture. The Scorpius Centaurus star cluster passed close (150 ly) to earth during the Pliocene, and there are remnants of supernovae from about that timeframe. The iron isotopes are more evidence.
There are other explanations for the extinctions. The Isthmus of Panama formed about that time, which changed ocean currents and may have disrupted migration paths. The climate was cooling and the ice caps formed. As the ice caps freeze and thaw they change salinity (creating cold saline water that sinks to the depths with they freeze, and brackish surface water when they thaw), and more extreme thermal gradients, as cold and saline polar "bottom water" settles into the ocean depths. This changes currents and reduces upwelling.
It could have been any of these factors, or some combination of all of them. The Pliocene extinctions were not sudden like the Permian and Cretaceous-Tertiary extinctions.
I am curious as to why this would have driven marine animals to extinction without having a similar effect on terrestrial animals. I would want this explained before giving this theory any credence.
If the ocean life got a wallop of cosmic rays, wouldn't the land creatures fare even worse?
Neither the article nor paper's abstract went into it, so I instead have to hypothesize that perhaps the ocean surface micro-organisms were especially sensitive to radiation, leading to an ecological collapse... or maybe the supernovae and extinction events are even unrelated.
simplest explanation for the extinctions is, Chuck Norris.
The dinosaurs died out roughly 70 million years ago (except for birds).
I was watching this documentary about feathered dinosaurs. It had an interview with a Chinese Palaeontologist who has done a lot of work on feathered dinosaurs and specifically the feathered raptors that evolved into birds. At the end he terminated the film by excusing himself to the interviewer because his wife had asked him to buy a dinosaur for dinner on his way home. The documentary ended with a shot of him heading home from the market carrying a chicken. It puts a whole new perspective on going to Kentucky Fried if you realise that you are munching on a bucket of dinosaur drumsticks.
The supernova hypothesis is not just conjecture. The Scorpius Centaurus star cluster passed close (150 ly) to earth during the Pliocene, and there are remnants of supernovae from about that timeframe. The iron isotopes are more evidence.
Supernovae..., perhaps the answer to the Fermi Paradox.
FTFY
Genuinely can't tell if this is sarcasm, but if it was its not terribly funny. B+ trolling.
Because iron-60 is radioactive, if it was formed with the Earth it would be long gone by now. So, it had to have been rained down on us
Joe: We know for sure how old the Earth is, because of radiometric dating.
Bob: Hey cool. BTW, what's that stuff there?
Joe: Iron-60.
Bob: Cool. Wait a minute, how could that still be there?
Joe: Well, it must have fallen on us.
Bob: Cool, how do you know that?
Joe: Er, well ... if it was formed with the Earth it would be long gone by now. So, it had to have been rained down on us.
Bob: Oh ... OK. That's logical ... I guess.
{...}
Bob: Er, so that other stuff over there ... how do you know that didn't rain down on us?.
Joe: I hate you.
Thank you! I am now reassured. I was terrified by the prospect of the Great Tribulation but I now know that this won't happen before the next nearby supernova. We know that IK Pegasi - the closest supernova candidate - is too far away to cause us any harm so I can now assume that the Great Tribulation is not due before we approach another candidate so in several millions years. Thanks again! I can go back sinning.
I've recently viewed a science video with my kids talking about breeding chickens to be more dinosaur like. If you've seen them run, you'd be impressed at how raptor like they probably are. Obviously the claws have been replaced by wings, but the frame and movement looks like it hasn't changed much in the last 70 million years.
Later when we were taught absorption, reflection, scattering and transmission it dawned on me that even if the mirrors were nearly 99.9999% reflective, even that 1.0e-06 or 1.0e-12 scattering would degrade the images and eventually the later images will be less bright and eventually fade to black.
Reflection and scattering from clouds from one supernova burst, and we were bathed by repeated reflections for 10,000 years? And the radiation remained potent for that long? It is boggles my tiny brain. Hope the guys doing the math did not forget a decimal point or two.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Their ancestors 70 million years ago also had wings and feathers. Birds have probably been around since the Jurassic Period, long before T-rex and velociraptor for example. They still had teeth back then so would have looked a bit weird though.
They're one of the many filters. Many stars pass through areas of high numbers of supernovas such as star forming regions. These regions also have large numbers of blue giants that put out a lot of radiation. There's also areas of dense stars where close enough encounters with other stars are likely to perturb any planets orbit as well as send in more material from comet clouds and such.
Just in a stars travels around the galaxy over billions years, there's a lot of stuff that will screw life developing.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
It puts a whole new perspective on going to Kentucky Fried if you realise that you are munching on a bucket of dinosaur drumsticks.
So it's probably yes, the answer to the age old question; do dinosaurs taste like chicken? Clearly my interpolation from watching flintsones cartoons is wrong here.
"Develop interstellar travel" Stop watching TV, it is bad for you. The closest star to Earth is Alpha Centuri and it is 4.22 light years from Earth. Just a guess, but you won't be going there on your imagined interstellar space ship at the speed of light. If you are lucky, you might get to half that speed. Then there is the speed up and slow down phases. So you might get there in 10 years.
You'll be wanting to bring along a lot of food...you cannot build a space ship that big. So you'll be wanting to grow it which means an entire hanger full of plants and what-not, even plants must eat. That's a mighty massive space ship you are assuming...and you need to get all that mass to half light speed.
I know, you could open up a hyperspace window...oh, except that would mean quite an expenditure of energy and done in such a way that it didn't rip your ship apart.
Cancer kills an individual creature. Even if 90% of a species is killed by cancer most species would bounce back. However a mutation that made all of an individuals off spring a single sex would lead to extinction of most species. Our genome is full of defenses against these types of mutations and the genomes of more than a few species are littered with the scares of near misses.
As opposed to what, a small supernova potato?
How about just "supernova"?