[physics.pop-ph] Exploration of planetary bodies within our solar system will be essential for understanding the origin of life on Earth and the distribution of life in the universe.
Planetary protection policy is concerned with balancing this desire for exploration against the risks of contaminating alien planets with Earth life, and contaminating Earth with alien life. However, at present, we have no fundamental scientific understanding of life’s emergence or its nature beyond Earth.
Given this nearly complete ignorance about the possibility of alien life, or Earth life’s capacity to expand beyond our planet, it is difficult to reason about the real risks of space exploration. Here we contend that contemporary understandings of the risks of forward contamination are based on arguments which inconsistently apply our incomplete knowledge to the problem.
We reason that a more assertive posture towards space exploration, focused on determining whether other planets in the solar system are inhabited, is warranted and explain why such a posture may not increase the epistemic risks of planetary contamination. Finally, we explore the consequences of our arguments for planetary protection protocols, and life detection efforts.
The matrix of possibilities resulting from being able to coarse grain both the probability space for abiogenesis into exceptionally rare or exceptionally common, and the probability space for planetary invasion into exceptionally hard or exceptionally easy. Here, we talk about a biosphere being “robust” to invasion or contamination similarly to how the term is used in evolutionary biology—that it can persist (does not collapse, and is not significantly altered) in the face of perturbation (contact from exogenous life). — [physics.pop-ph]
Harrison B. Smith, Cole Mathis
Comments: 18 pages, 2 figures
Subjects: Popular Physics (physics.pop-ph); Other Quantitative Biology (q-bio.OT)
Cite as: arXiv:2609.10604 [physics.pop-ph] (or arXiv:2609.10604v1 [physics.pop-ph] for this version)
https://doi.org/10.48550/arXiv.2609.10604
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Submission history
From: Harrison Smith
[v1] Tue, 8 Sep 2026 05:38:54 UTC (1,229 KB)
https://arxiv.org/abs/2609.10604
Astrobiology
