NASA’s Nexus for Exoplanet System Science and the NASA Astrobiology Institute held a series of joint Exoplanet Biosignatures Workshop Without Walls from June to July 2016, including an in-person workshop, in Seattle, WA that brought together the astrobiology, exoplanet, and mission concept communities to review, discuss, debate, and advance the science of biosignatures. A broad range of experts were engaged, merging the interdisciplinary reaches of NExSS, the NAI, NASA’s Exoplanet Exploration Program (ExEP), and international partners, such as the European Astrobiology Network Association (EANA) and Japan’s Earth Life Science Institute (ELSI).

The report from the NExSS Exoplanet Biosignatures Workshop Without Walls is available to download at:

The workshop focused around three goals:
1. State of the Science Review: What are known remotely observable biosignatures, the processes that produce them, and their known non-biological sources?
2. Advancing the Science of Biosignatures: How can we develop a more comprehensive conceptual framework for identifying additional biosignatures and their possible abiotic mimics?
3. Confidence Standards for Biosignature Observation and Interpretation: What paradigm informed by both scientists and technologists could establish confidence standards for biosignature detection?

Workshop activities included six online videoconference sessions providing interactive review of the State of the Science preliminary to the in-person meeting. Participants spanned astronomy, planetary science, Earth sciences, heliophysics, biology, instrument/mission development, and engineering from around the world. The workshop culminated in five review papers on the science and technology of remote searches for signs of life on exoplanets. Broad participation was solicited for these papers, which will serve as an interdisciplinary, educational, state of the art reference for use across a wide community.

Recordings of talks and presentation slides are archived and available to view at: