Supernova ash found in fossils could solve a big extinction mystery

Source: NASA
Source: NASA

Scientists just found ash from a supernova in bacteria fossils, suggesting an exploding star may have been responsible for an extinction event millions of years ago.

When a star goes supernova, its core collapses. Then it explodes and ejects a huge cloud of the radioactive isotope iron 60. There is no natural way to get iron 60 on Earth, according to the research

Previously, scientists have found evidence of supernova dust in ocean sediment. Now researchers have taken a closer look at that sediment and discovered iron 60 inside tiny fossils of magnetotactic bacteria. 

Artist's impression of a supernova
Source: 
NASA, ESA, G. Bacon (STScI)

The fossils first appeared about 2.6 million to 2.8 million years ago. Our solar system spent close to one million years passing through the could of supernova debris, according to study co-author Shawn Bishop.

This supernova rain happened around the same time a big extinction event wiped out several types of mollusks on Earth, according to the research. The scientists can't say for sure whether the supernova triggered this extinction, but the evidence seems to suggest it. 

It's also puzzling that the Earth took so long to travel through the supernova debris, since an exploding star sends material flying initially at millions of miles per hour.

"There's a mystery there," Bishop told Business Insider. "Can the ejecta from a supernova explosion be spread out in time? This is something that needs to be explained and understood."

How likely are you to make Mic your go-to news source?

MORE FROM

Twitter was flagging tweets including the word "queer" as potentially "offensive content"

Why Twitter put the word "queer" in the same category as violent, sexual imagery.

How Mark Zuckerberg wants to transform society through Facebook Groups

Facebook has a new mission.

California is making so much solar energy the rest of the country looks like a joke

They're literally paying other states to take their solar power.

This summer, Americans will get the rare chance to see a total solar eclipse

Anyone in the continental U.S. should mark their calendars.

This hilarious 'Floor is lava' meme is way too real for every single millennial

When you were a kid, the floor was just lava. Now it's way more complicated.

The new iOS 11 beta is out and Apple has changed your iPhone's message effects again

A new iOS 11 beta is out and iMessage has a new trick.

Twitter was flagging tweets including the word "queer" as potentially "offensive content"

Why Twitter put the word "queer" in the same category as violent, sexual imagery.

How Mark Zuckerberg wants to transform society through Facebook Groups

Facebook has a new mission.

California is making so much solar energy the rest of the country looks like a joke

They're literally paying other states to take their solar power.

This summer, Americans will get the rare chance to see a total solar eclipse

Anyone in the continental U.S. should mark their calendars.

This hilarious 'Floor is lava' meme is way too real for every single millennial

When you were a kid, the floor was just lava. Now it's way more complicated.

The new iOS 11 beta is out and Apple has changed your iPhone's message effects again

A new iOS 11 beta is out and iMessage has a new trick.