25m-year-old dust on ocean floor at odds with Supernovae hypotheses

Researchers have recently analysed galactic dust from the last 25 million years that has settled on the ocean floor, which has provided new insight into supernovae theories.

They have analysed extraterrestrial dust thought to be from supernovae, which has settled on ocean floors to determine the amount of heavy elements created by the massive explosions.

Anton Wallner, from the Research School of Physics and Engineering at The Australian National University (ANU), said that small amounts of debris from these distant explosions fall on the earth as it travels through the galaxy.

They found that there was much less of the heavy elements such as plutonium and uranium than they expected, he further added.

The findings are at odds with current theories of supernovae, in which some of the materials essential for human life, such as iron, potassium and iodine are created and distributed throughout space.

Supernovae also create lead, silver and gold, and heavier radioactive elements such as uranium and plutonium.

Dr Wallner's team studied plutonium-244 which serves as a radioactive clock by the nature of its radioactive decay, with a half-life of 81 million years.

The team analysed a 10 centimetre-thick sample of the earth's crust, representing 25 million years of accretion, as well as deep-sea sediments collected from a very stable area at the bottom of the Pacific Ocean.

Dr Wallner further mentioned that it seems that these heaviest elements might not be formed in standard supernovae after all and it might require rarer and more explosive events such as the merging of two neutron stars to make them.