On the likelihood of non-terrestrial artifacts in the Solar System (1111.1212v1)

Abstract: Extraterrestrial technology may exist in the Solar System without our knowledge. This is because the vastness of space, combined with our limited searches to date, implies that any remote unpiloted exploratory probes of extraterrestrial origin would likely remain unnoticed. Here we develop a probabilistic approach to quantify our certainty (or uncertainty) of the existence of such technology in the Solar System. We discuss some possible strategies for improving this uncertainty that include analysis of moon- and Mars-orbiting satellite data as well as continued exploration of the Solar System.

• The paper develops a probabilistic model using Bayesian inference to evaluate the likelihood of non-terrestrial artifacts in defined Solar System volumes.
• It shows that limitations in current observational resolution and surveyed coverage inhibit definitive detection of these potential artifacts.
• The study advocates for targeted, high-resolution exploration of celestial bodies like the Moon and Mars to incrementally confirm or refute NTA presence.

On the Likelihood of Non-Terrestrial Artifacts in the Solar System

This paper systematically addresses the possibility of unobserved extraterrestrial technology residing within our Solar System. It employs a probabilistic framework to assess the confidence level of detecting or ruling out non-terrestrial artifacts (NTAs), such as interstellar probes, within predefined volumes of space. The analysis distinguishes between technological artifacts that could be detectable through current or near-future observational strategies and those concealed either deliberately or due to insufficient technological advancement on our part.

Theoretical Framework

Central to the paper's argument is the construction of a probabilistic model to evaluate the likelihood of NTAs being present yet undetected in the Solar System. The framework hinges on defining a hypothesis $H$ that NTAs exist within a specific spatial volume $V$. The authors then employ Bayes' theorem to compute the conditional probability $p(\bar{H}|\bar{V}_{R})$, representing the confidence that no NTAs reside within volume $V$ given the absence of detection from any search with resolution $R$. This formulation takes into account both the extent of the volume surveyed ($\bar{V}_{R}/V$) and the comparative spatial resolution ($R$) necessary to detect NTAs assumed to have a size range between 1 to 10 meters.

Implications for Solar System Search

The practical implications for astronomical searches are significant: much of the current astronomical infrastructure lacks sufficient resolution and coverage to confidently ascertain the absence of NTAs. The authors identify that only a minuscule fraction of the Solar System has been observed at the required resolution to potentially detect NTAs of the proposed size, exemplified by a systematically more complete search of Earth's surface compared to other celestial bodies.

The search for NTAs is framed within the context of possible remote exploration strategies by extraterrestrial intelligences, drawing parallels with future human explorations using similar-sized probes. As the Solar System is vast, achieving comprehensive coverage at necessary resolutions remains a significant challenge, one that current explorative missions are only beginning to address.

Towards a Systematic Search Strategy

The authors argue for the potential utility of NTAs residing within various locations such as near-Earth objects, the moon, Mars, and stable Lagrange points. Given these strategic considerations, there is an implication that targeted exploration using advanced satellite data from missions like the Lunar Reconnaissance Orbiter could incrementally rule out these hypotheses. A methodical analysis of thermal signatures, spectral anomalies, or unexpected mineral compositions could signal NTAs, though such an endeavor remains speculative without technological improvements.

Conclusion

In conclusion, the probabilistic framework proposed by the authors emphasizes the importance of methodical, high-resolution examination of the Solar System, positing that while the evidence for NTAs is currently lacking, a conclusive dismissal based on current search efforts is premature. This work encourages continued exploration and refinement of detection methodologies, highlighting the potential to validate or refute the presence of extraterrestrial probes with future technological advancements. These efforts form a nuanced part of the broader SETI discourse, aiming to bridge the gap between theoretical possibility and observational reality in the search for extraterrestrial intelligence.