Supernovae are powerful explosions in space which are triggered when massive stars die. These stellar events forge many different elements — including potassium, iodine, and iron—which are essential for life. But a recent report explains that these events also release heavier elements too — like gold and lead — and radioactive elements — like plutonium and uranium — which counters some of the current ideology.
Now, Scientists plumbing the depths of the ocean have made a surprise finding that could change the way we understand supernovae. They have analysed extraterrestrial dust thought to be from supernovae, that has settled on ocean floors to determine the amount of heavy elements created by the massive explosions.
The study conducted by the Australian National University that examined plutonium 244 obtained from the deep earth crust and ocean sediments implies that heavy elements were made only in super massive explosions like the merging of two neutron stars.
“Small amounts of debris from these distant explosions fall on the earth as it travels through the galaxy,” explained Australian National University researcher Anton Wallner. “We’ve analyzed galactic dust from the last 25 million years that has settled on the ocean and found there is much less of the heavy elements such as plutonium and uranium than we expected.”
In studying a 10cm thick sample of dust that represents 25M years of accretion of galactic dust, the researchers found 100 times less plutonium-244 than predicted. The radioisotope is thought to be produced by standard supernovae. It’s startling scarcity suggests otherwise.
“It seems that these heaviest elements may not be formed in standard supernovae after all,” said Wallner. “It may require rarer and more explosive events such as the merging of two neutron stars to make them.”
“Radioactive elements in our planet such as uranium and thorium provide much of the heat that drives continental movement, perhaps other planets don’t have the same heat engine inside them,” said Wallner.
The findings don’t just reveal a bit more about our own planet, but also tell scientists a bit more about supernovae. Not only that, but it’s possible that the Earth’s oceans could contain more evidence for this type of space dust.
This is of course just the first study of its kind to make such a claim. Additional experiments will be needed to confirm the findings.
Bottom line: a supernova is a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the Sun or any ordinary star is expected to emit over its entire life span, before fading from view over several weeks or months. A supernova sends titanic shock waves rumbling through interstellar space. It leaves behind an ultra-dense neutron star in its wake, which spews out a blizzard of high-energy particles.
Journal reference: http://goo.gl/LFK2BH.