Origin of Organic Molecules in the Tissint Meteorite

All articles by Wretch Fossil are here: http://www.wretch.cc/blog/lin440315&category_id=0

Figure 1. Wood cell structures in the Tissint meteorite. Source: https://www.flickr.com/photos/fossil_lin/54643468081/in/dateposted-public/

Abstract

The Tissint meteorite’s organic molecules have been attributed solely to abiotic processes. However, morphological and chemical evidence suggests a biogenic contribution remains plausible. This note argues why the standard abiotic model may be incomplete and calls for renewed investigation.

Main Text

The Tissint Martian meteorite, which fell in Morocco in 2011, has become a key specimen in the debate over possible traces of ancient life on Mars. In a 2023 study published in Science Advances, Steele et al. reported complex organic carbon compounds embedded within olivine macrocrystals and melt veins, concluding that these organics are entirely the product of abiotic geochemical processes.

While the high-temperature geochemistry explains some carbon species plausibly, a growing body of evidence suggests that the abiotic interpretation is incomplete. Morphological, chemical, and contextual factors point to the possibility that some of Tissint’s carbon compounds may instead reflect the remnants of ancient Martian biology that survived partial melting and shock.

The paper focuses on molecular analyses but pays minimal attention to highly organized polygonal and tubular structures visible in high-resolution imaging. These cell-like features closely resemble terrestrial wood cells or organized biological tissues. Repeated, contiguous “cell walls” in Tissint appear ordered and confined to specific mineral zones — a hallmark of preexisting biological templates.

Steele et al. detected aromatic and aliphatic hydrocarbons, including PAHs and organomagnesium species. These can arise from abiotic synthesis but are also well-known pyrolysis products of lignin and cellulose. Impact-induced heating could degrade fossil wood, preserving only heat-stable aromatic clusters.

Mars’ crust is complex, with interbedded igneous and sedimentary phases. Fossilized carbon could be entrained as xenoliths or inclusions during magma ascent. On Earth, fossil wood is sometimes preserved in volcanic tuffs and basalts — a direct analogue for Mars.

While the paper presents a robust case for abiotic pathways, it does not conclusively rule out a biogenic contribution. The morphological evidence and chemical match to fossil wood pyrolysis products point to the need for renewed, unbiased testing.

Key Takeaway

Abiotic synthesis pathways do not automatically exclude the preservation of fossil biosignatures. Tissint’s organic carbon deserves a full, unbiased biogenic vs. abiotic re-examination. 

Wretch Fossil’s website:http://wretchfossil.blogspot.com/

Source: https://wretchfossil.blogspot.com/2025/07/origin-of-organic-molecules-in-tissint.html