Big Fireworks II

You don’t have to get too close to an exploding star for it to ruin your day. A recent study, for example, says that one or more exploding stars about 65 light-years from Earth could have caused a mass extinction.

The extinction took place about 360 million years ago. Some fish and other animals survived, but most organisms died off. Over the decades, scientists have proposed several possible causes, from huge volcanic eruptions to a collision with a comet or asteroid.

But the new study has another explanation: a supernova.

According to the study, a massive star — or maybe two of them — exploded when it reached the end of its life. That flooded Earth with radiation, destroying its protective ozone layer. Later, the supernova also bathed our planet in cosmic rays — heavy particles accelerated to near the speed of light. The combination created both a long decline in life — lasting a few hundred thousand years — and a shorter “pulse” of extinctions.

Other studies in recent years also suggested supernovae as engines of mass extinction. None of those ideas has been confirmed. But the new study offers a way to confirm it. Researchers say that debris from the explosion could be found in rock layers from the time of the die-off. In particular, even tiny amounts of plutonium or some other radioactive elements would be the “smoking gun” — confirmation that an exploding star zapped Earth almost 360 million years ago.

Script by Damond Benningfield