Could supernovae be responsible for two mass extinctions on Earth? 💥

Nearby stellar explosions may have influenced two major mass extinctions on Earth. A recent study explores this link between supernovae and species disappearances.

Researchers from Keele University analyzed the impact of supernovae on Earth's atmosphere. These stellar explosions could have damaged the ozone layer, exposing life to harmful solar radiation. The Ordovician and Late Devonian extinctions, occurring 445 and 372 million years ago respectively, are the focus of this study.


The study, published in Monthly Notices of the Royal Astronomical Society, establishes a correlation between the rate of nearby supernovae and these extinctions. Supernovae disperse heavy elements essential for life, but their proximity can be devastating. This duality between creation and destruction is at the heart of the research.

Scientists mapped massive stars near the Sun to estimate the frequency of supernovae. Their method allowed them to compare this frequency with that of mass extinctions attributed to external causes. The results support the hypothesis of a link with supernovae.

Only two nearby stars, Antares and Betelgeuse, could potentially explode as supernovae in the near future. However, their distance of over 500 light-years minimizes the risks to Earth. Simulations confirm that their explosions would have no significant impact on our planet.

This research opens new perspectives on cosmic threats to terrestrial life. It highlights the importance of understanding stellar phenomena to anticipate their effects on our environment. Supernovae, though distant, remain a crucial subject of study for scientists.

The collected data will also be useful for the development of gravitational wave detectors. These instruments help study the structure of the Universe and the origins of cosmic phenomena. Research on supernovae thus contributes to multiple fields of astrophysics.

Why are the Ordovician and Late Devonian extinctions unique?

These mass extinctions primarily affected marine life, which was dominant on Earth at the time. The Ordovician saw the disappearance of 60% of marine invertebrates, while the Late Devonian eliminated 70% of all species.

Unlike other extinctions, such as the Cretaceous-Tertiary event caused by an asteroid impact, these events lack clear terrestrial causes. Supernovae offer a plausible explanation for these sudden disappearances.

These periods also correspond to major shifts in marine biodiversity. Supernovae may have accelerated these transitions by eliminating certain species and favoring the emergence of others.

How can a supernova affect Earth?

A nearby supernova can damage Earth's ozone layer, exposing life to high levels of ultraviolet radiation. This radiation can cause genetic mutations and disrupt ecosystems.

Supernova explosions also release energetic particles that can ionize the atmosphere. This ionization may lead to acid rain and alter Earth's global climate.

Supernovae also disperse heavy elements into space, which are essential for the formation of new stars and planets. However, an explosion too close could saturate Earth's environment with these elements, with consequences that are still poorly understood.