astrobiology

COSMIC TRACES

How can we detect extraterrestrial life if it differs from known life?
I will answer on November 28, focusing on life-substate interactions and their products – ichnofossils!

The quest for extraterrestrial life has long captivated humanity, yet potential extraterrestrial organisms might exhibit unfamiliar forms and biochemistry. How can we detect extraterrestrial life if it differs from known life? The talk on November 28 aims to address this question by focusing on life-substate interactions and their products – ichnofossils. As a document of biological behaviour, ichnofossils potentially allow us to detect any type of life, regardless of shape, size, or biochemistry of the tracemaker, thus opening a novel direction in astrobiological research.

Extreme paleoenvironments provide insights into the limits of life on Earth and suggest where its traces might exist elsewhere in the Universe. In this context, the ichnological heritage of Sardinia (Italy) offers spectacular examples of trace fossils produced in harsh conditions, providing robust predictive models for assessing which areas of Mars are more likely to preserve potential ichnofossils.

Additionally, billions of ichnofossils have been documented in the largest Permian megacaldera of Europe, the Bolzano Megacaldera, despite the scarcity of animal body fossils. This, along with examples from Portugal and the Apennines, highlights another astrobiological advantage of ichnofossils: their resilience to geological processes that typically obliterate other biosignatures. Ichnofossils do not decompose and might even withstand meteorite impacts.

The talk will also present the ichnofossil-like structures that have been documented so far in the Vera Rubin Ridge on Mars and in Martian meteorites such as Yamato 000593. Although these findings do not definitively prove the existence of life on Mars, they show that the future of astroichnology holds great promise. By integrating artificial intelligence and paleontological predictive modelling, ichnology could revolutionize our understanding of life in the cosmos, unlocking the secrets of life beyond Earth.