NASA AND THE SEARCH FOR TECHNOSIGNATURES A Report from the NASA Technosignatures Workshop NOVEMBER 28, 2018 NASA TECHNOSIGNATURES WORKSHOP REPORT CONTENTS 1 INTRODUCTION .................................................................................................................................................................... 1 What are Technosignatures? .................................................................................................................................... 2 What Are Good Technosignatures to Look For? ....................................................................................................... 2 Maturity of the Field ................................................................................................................................................... 5 Breadth of the Field ................................................................................................................................................... 5 Limitations of This Document .................................................................................................................................... 6 Authors of This Document ......................................................................................................................................... 6 2 EXISTING UPPER LIMITS ON TECHNOSIGNATURES ....................................................................................................... 9 Limits and the Limitations of Limits ............................................................................................................................ 9 Upper Limits in Continuous Wave Radio Searches ................................................................................................. 10 Upper Limits in Pulsed Radio Searches .................................................................................................................. 13 Upper Limits in Optical/Near-Infrared (NIR) Laser Searches .................................................................................. 14 Upper Limits on Waste Heat and Stellar Obscuration ............................................................................................. 16 2.5.1 Dyson Spheres and Megastructures ............................................................................................................. 16 2.5.2 Upper Limits on Megastructures in Transit ................................................................................................... 17 2.5.3 Upper Limits on Waste Heat from Stars ....................................................................................................... 17 2.5.4 Upper Limits on Waste Heat from Galaxies .................................................................................................. 18 Upper Limits on Solar System Technosignatures ................................................................................................... 18 3 STATE OF THE ART OF TECHNOSIGNATURE SEARCHES ............................................................................................ 20 Radio Technosignatures .......................................................................................................................................... 20 3.1.1 Existing Telescopes and Telescope Arrays .................................................................................................. 21 3.1.2 Existing Analysis Methods and Hardware ..................................................................................................... 22 Optical/NIR Laser Technosignatures ....................................................................................................................... 24 3.2.1 Existing Projects ........................................................................................................................................... 24 Algorithms and Search Strategies ........................................................................................................................... 25 Searches for Astrophysical Exotica ......................................................................................................................... 25 Other Ongoing Searches ......................................................................................................................................... 26 4 CURRENT AND NEAR-TERM ASSETS AND PROJECTS IN THE TECHNOSIGNATURE FIELD .................................... 27 Overview ............................................................................................................................................................................... 27 Technosignature Capabilities at Radio, Millimeter, and Sub-millimeter Wavelengths ............................................. 27 Technosignature Capabilities at Ultraviolet, Optical, Infrared (UVOIR) Wavelengths ............................................. 29 4.2.1 Targeted UVOIR Searches ........................................................................................................................... 29 4.2.2 Space-based Facilities .................................................................................................................................. 29 4.2.3 Ground-based Facilities ................................................................................................................................ 30 Solar System Artifacts and Interlopers .................................................................................................................... 31 Developing Target List for Technosignature Research ........................................................................................... 32 Connections and Potential Partnerships with Industry ............................................................................................ 32 Data Analysis ........................................................................................................................................................... 33 5 EMERGING AND FUTURE OPPORTUNITIES IN TECHNOSIGNATURE DETECTION .................................................... 34 Introduction ........................................................................................................................................................................... 34 Understanding Technosignatures from Theoretical Prospects ................................................................................ 35 5.1.1 Communication Technosignatures ............................................................................................................... 36 NASA TECHNOSIGNATURES WORKSHOP REPORT 5.1.2 Atmospheric Technosignatures .................................................................................................................... 37 5.1.3 Structural Technosignatures ......................................................................................................................... 38 5.1.4 Planet-scale Technosignatures ..................................................................................................................... 39 5.1.5 Time-Evolution of Technosignatures ............................................................................................................ 40 5.1.6 Activities in Disciplines Relevant to Technosignatures ................................................................................. 41 New Approaches to Detecting Technosignatures ................................................................................................... 44 5.2.1 New Surveys with Current Instruments ......................................................................................................... 44 5.2.2 New Instruments: Optical and IR .................................................................................................................. 45 5.2.3 High-contrast Imaging Systems .................................................................................................................... 45 5.2.4 New Instruments: Radio ................................................................................................................................ 47 5.2.5 New Instruments: Non-EM ............................................................................................................................ 47 5.2.6 Emerging Technologies Relevant to SETI .................................................................................................... 49 Ways to Catalyze Significant Advances .................................................................................................................. 49 5.3.1 Private Partnerships ...................................................................................................................................... 50 5.3.2 Philanthropic and Academic Partnerships .................................................................................................... 50 5.3.3 Partnerships with Other Federal Programs ................................................................................................... 52 6 REFERENCES ..................................................................................................................................................................... 55 7 ACRONYMS ......................................................................................................................................................................... 65 NASA TECHNOSIGNATURES WORKSHOP REPORT 1 INTRODUCTION