Exploding Stars May Have Assaulted Ancient Earth (sciencemag.org) 24
sciencehabit shares a report from Science Magazine: Over the past 2 decades, researchers have found hundreds of radioactive atoms, trapped in seafloor minerals, that came from an ancient supernova explosion marking the death of a nearby star. Erupting from hundreds of light-years away, the flash of x-rays and gamma rays probably did no harm on Earth. But the expanding fireball also accelerated cosmic rays -- mostly nuclei of hydrogen and helium -- to close to the speed of light. These projectiles arrived stealthily, decades later, ramping up into an invisible fusillade that could have lasted for thousands of years and might have affected the atmosphere -- and life. In a flurry of studies and speculation, astronomers have sketched out their potential effects, including a depleted ozone layer, cancer-causing particles, wildfires, and a cooling of the climate that could have helped initiate the ice ages 2.5 million years ago. Most paleontologists are yet to be convinced, but astronomers argue that such supernovae could explain some extinction events that lack customary triggers like volcanic outbursts or asteroid impacts.
Hundreds of atoms (Score:1)
When dealing with something like atoms, hundreds is not a big number...
Re: (Score:3)
When dealing with something like atoms, hundreds is not a big number...
From reading TFA, they think they're from a supernova explosion in what is now a part of the Scorpius-Centaurus OB Association (Sco OB2), which seemed to be in the perfect spot—300 light-years from Earth—about 2.5 million years ago. How many atoms of iron-60 would you expect to (easily) find here from that radius, so long ago?
One team also found 181 atoms of plutonium-244, which they believe is a product of collisions between neutron stars—cinders left behind by supernovae. These collis
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REAL NEWS: Natural Plutonium found
Actually we knew that natural Pu existed when the earth was formed due to the ratios of specific decay products but we believed it had all since decayed. And this is the second wave of papers from this team. That was the headline in the first set of papers when the raw data was released. This is the second set where they are theorizing about the effects of what they observed.
Re: Hundreds of atoms (Score:2)
I'm fascinated by their ability to quantify the number of atoms so precisely. AMS technology is really impressive. I found myself more interested in that aspect of the article than the scientific conclusions and speculation.
Please (Score:1, Funny)
My dog died in a supernova explosion, you insensitive clod!
Re:Please (Score:4, Funny)
You can't be Sirius.
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I can be and quit calling me Sirius
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Re: (Score:3, Informative)
Modded "offtopic"? /. humour?
Is there no longer any recognition of classic
Oh the humanity.
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Is there no longer any recognition of classic /. humour?
No. Slashdot has been taken over by humorless progressives/autists.
Assault charges? (Score:2)
What's the statute of limitations on interstellar assault? How many light years before you can't pursue charges?
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Re: Assault charges? (Score:2)
When you're a star, they let you grab them in the
This is why we need to get off planet (Score:3)
and become a space faring species with colonies hundreds of light years away. A supernova close by could wipe out complex life on earth. This is in addition to the other threats that could harm us, eg: asteroid impact, or things as a result of our own stupidity like climate change and atom bombs.
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Yeah, I know "solipsist" is probably inaccurate in that AC believes in other people and just doesn't care about them, but I thought it sounded a little gentler than "sociopath."
Interesting idea. (Score:1)
Math... (Score:3)
"hundreds of light-years away...."
"decades later...."
Math. As if anyone really uses it anymore.
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Allow me to clarify: "These projectiles arrived stealthily, decades [after the arrival of the flash of x-rays and gamma rays] later"
The word "later" is meant in respect to the arrival time of the x-rays, not the creation time of said x-rays.
Re: Math... (Score:2)
And yes, I was referring to arrival time, though so long as I'm referring to the same time, creation or arrival, the difference is ...?
Re: Math... (Score:1)