Wood-Cell–Like Microstructures in Martian and Extraterrestrial Samples: Comparative Interpretations

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Abstract

Reports of carbon-bearing materials and microstructures in Martian meteorites, rover imagery, and asteroid samples continue to provoke debate about their potential biological origins. We present three case studies—tubular structures in Martian meteorite NWA 16788, nodule-rich outcrops imaged by Perseverance at “Cheyava Falls,” and nanofibrils in Ryugu asteroid material. Mainstream interpretations emphasize abiotic mineralogical processes (shock melt, vivianite, phyllosilicate crystallization), while alternative interpretations highlight striking morphological parallels to terrestrial wood cells, including vessel elements and cellulose-like fibrils. The cross-scale consistency of these features, spanning micrometers to nanometers, suggests the possibility of fossilized tissue templating. We discuss competing models and argue that integrated morphological, spectroscopic, and isotopic analyses will be essential to resolve whether these structures represent abiotic mimics or preserved remains of ancient life.

Keywords: Mars; meteorites; fossil wood; biosignatures; Ryugu asteroid

1. Introduction

The search for biosignatures on Mars and other planetary bodies is central to astrobiology. Fossil wood cells on Earth exhibit diagnostic architectures—vessels, tracheids, pits, and fibrillar ultrastructure—that provide a useful template when evaluating extraterrestrial textures. Several Martian meteorites (e.g., NWA 16788, EETA79001, Tissint) contain microstructures resembling vascular plant tissue. Similarly, the Perseverance rover has imaged nodules and organics within sedimentary outcrops at Jezero crater. Finally, Ryugu asteroid particles reveal nanostructures suggestive of fibrillar templating.

The interpretation of these features remains controversial. Planetary scientists typically favor abiotic models (mineral precipitation, shock features, diagenesis), while independent investigators have proposed biogenic hypotheses. Here we compare three representative cases to illustrate the tension between these views.

2. Materials and Methods

This study analyzed images from three distinct sources: (1) thin-section micrographs of Martian meteorite NWA 16788; (2) rover-acquired images from Perseverance’s SHERLOC instrument at the “Cheyava Falls” outcrop; and (3) TEM images of Ryugu asteroid particle C0068 published in peer-reviewed sources. Annotated high-resolution images were accessed from Fossil_Lin’s Flickr collection, preserving scale bars and interpretive arrows.

Comparative morphological analysis was performed by examining tubular, nodular, and fibrillar textures across micro- to nanometer scales. Each structure was interpreted under two frameworks: (a) mainstream mineralogical models, and (b) the wood-cell hypothesis, which emphasizes parallels with terrestrial xylem architecture.

3. Results

3.1 NWA 16788 Meteorite

Observation: Tubular structures with pits, 30–80 µm across.Mainstream view: Shock melt vein textures, vesicles, mineral inclusions. Alternative view: Fossilized vessel elements.