[Paper Review] Searching for technosignatures in exoplanetary systems with current andfuture missions br

Jacob Haqq‐Misra, Edward W. Schwieterman+10 more|arXiv (Cornell University)|Sep 1, 2022

Space Science and Extraterrestrial LifePhysics and Astronomy198 references22 citations

TL;DR

This paper synthesizes recommendations from the 2020 TechnoClimes workshop to advance the search for technosignatures in exoplanetary systems using current and future space and ground-based telescopes. It outlines detectable technosignatures across ultraviolet, optical, and infrared wavelengths—such as atmospheric pollutants, artificial lighting, optical beacons, megastructures, and interstellar probes—and emphasizes that null results from existing data can provide statistically meaningful upper limits, thereby guiding future mission design and broadening community engagement in technosignature science.

ABSTRACT

Technosignatures refer to observational manifestations of technology that could be detected through astronomical means. Most previous searches for technosignatures have focused on searches for radio signals, but many current and future observing facilities could also constrain the prevalence of some non-radio technosignatures. This search could thus benefit from broader participation by the astronomical community, as contributions to technosignature science can also take the form of negative results that provide statistically meaningful quantitative upper limits on the presence of a signal. This paper provides a synthesis of the recommendations of the 2020 TechnoClimes workshop, which was an online event intended to develop a research agenda to prioritize and guide future theoretical and observational studies technosignatures. The paper provides a high-level overview of the use of current and future missions to detect exoplanetary technosignatures at ultraviolet, optical, or infrared wavelengths, which specifically focuses on the detectability of atmospheric technosignatures, artificial surface modifications, optical beacons, space engineering and megastructures, and interstellar flight. This overview does not derive any new quantitative detection limits but is intended to provide additional science justification for the use of current and planned observing facilities as well as to inspire astronomers conducting such observations to consider the relevance of their ongoing observations to technosignature science. This synthesis also identifies possible technology gaps with the ability of current and planned missions to search for technosignatures, which suggests the need to consider technosignature science cases in the design of future mission concepts.

Motivation & Objective

• To expand the scope of technosignature research beyond radio signals by identifying detectable non-radio technosignatures using existing and upcoming astronomical facilities.
• To provide scientific justification for incorporating technosignature science as an ancillary objective in current and planned exoplanet missions.
• To identify technology gaps in current and future missions' ability to detect various technosignatures, informing future mission design.
• To encourage broader participation from the astronomical community by highlighting that negative results (upper limits) are scientifically valuable in constraining the prevalence of technosignatures.
• To promote interdisciplinary collaboration and funding support for technosignature research by demonstrating its feasibility with existing data and instruments.

Proposed method

• Synthesizing recommendations from the 2020 TechnoClimes workshop to identify and categorize potential technosignatures detectable at UV, optical, and infrared wavelengths.
• Analyzing the detectability of atmospheric technosignatures (e.g., SF6, O2, CH4), artificial surface modifications, optical beacons, megastructures, and interstellar probes using current and planned telescopes.
• Evaluating the capabilities of existing and upcoming facilities—such as JWST, ELTs, and mission concepts like Origins—against the requirements for detecting various technosignature types.
• Assessing the potential for detecting technosignatures through commensal observations and archival data analysis, without requiring dedicated observing time.
• Highlighting the role of machine learning and computational methods in identifying anomalies or filtering interference in large datasets relevant to technosignature detection.
• Emphasizing that null results—such as upper limits on signal presence—can be quantitatively meaningful and contribute to statistical constraints on technosignature prevalence.

Experimental results

Research questions

• RQ1 Which non-radio technosignatures are detectable with current and future space and ground-based telescopes across UV, optical, and infrared wavelengths?
• RQ2 How can existing and archival data from exoplanet missions be repurposed to place statistically meaningful upper limits on the prevalence of technosignatures?
• RQ3 What are the key technology gaps in current and planned missions that limit their ability to detect specific types of technosignatures?
• RQ4 In what ways can the broader astronomical community contribute to technosignature science through ancillary science goals or commensal observing?
• RQ5 How can false positives and detection thresholds be better understood and constrained to improve the reliability of future technosignature searches?

Key findings

• Current and future missions, including the James Webb Space Telescope (JWST), Extremely Large Telescopes (ELTs), and mission concepts like Origins, are the most promising facilities for detecting infrared technosignatures.
• Transiting megastructures and optical beacons are detectable with many current and near-future facilities, representing a significant expansion beyond traditional radio-based SETI.
• Atmospheric and surface-based technosignatures—such as artificial molecules (e.g., SF6) or reflective solar arrays—require the next generation of space telescopes and ELTs for detection.
• Null results from existing data, such as upper limits on signal presence, are scientifically valuable and can constrain the prevalence of technosignatures in the galaxy.
• The detection of interstellar flight or artificial objects in exoplanetary systems is feasible with future facilities, but requires further study to define detectability limits.
• Machine learning and computational tools can enhance technosignature detection by identifying anomalies or filtering interference in large datasets, even without new observations.