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Exoplanet Biosignatures Workshop Without Walls

The NASA Nexus for Exoplanet System Science (NExSS) and Astrobiology Program are hosting an Exoplanet Biosignatures Workshop Without Walls to review, frame, and advance the science and technology of remotely detectable biosignatures for the search for life on planets around other stars.


The 5 review papers on Exoplanet Biosignatures have been published as a Special Collection in the journal Astrobiology, Volume 18, Number 6.  There is also an introductory guide to the papers.  All papers are Open Access.

Exoplanet Biosignatures Workshop Without Walls

A NExSS & NASA Astrobiology Program Joint Workshop
Pre-workshop online activities were held during: June 13 - July 15, 2016
In-person workshop (and online broadcast): July 27 - 29, 2016, Seattle, WA

Be sure to register so that you can participate in the discussion forum!

Click here for the discussion forum.

Click here for past meetings agendas.

Click here to download the archived presentations.

Manage your group membership.

Science Organizing Committee:
Daniel Apai (University of Arizona, USA)
Shawn Domagal-Goldman (NASA GSFC, USA)
Yuka Fujii (ELSI, Japan, and NASA GISS, USA)
Lee Grenfell (DLR, ESA, Germany)
Nancy Y. Kiang (NASA GISS, USA)
Adrian Lenardic (Rice University, USA)
Nikole Lewis (STSci, USA)
Tim Lyons (University of California, Riverside, USA)
Hilairy Hartnett (Arizona State Univ., USA)
Bill Moore (Hampton University, USA)
Enric Palle (Instituto de Astrofísica de Canarias, Spain)
Niki Parenteau (SETI / NASA ARC, USA)
Heike Rauer (DLR, ESA, Germany)
Karl Stapelfeldt (NASA GSFC/JPL, USA)
Sara Walker (Arizona State University, USA)

Future exoplanet observations will soon focus on the search for life beyond the Solar System. Biosignatures to be sought are those with global, potentially detectable, impacts on a planet. Biosignatures occur in an environmental context in which geological, atmospheric, and stellar processes and interactions may work to enhance, suppress or mimic these biosignatures. Thus biosignature science is inherently interdisciplinary. Its advance is necessary to inform the design of the next flagship missions that will obtain spectra of habitable extrasolar planets.

This Exoplanet Biosignatures Workshop will bring together the astrobiology, exoplanet, and mission concept communities to review, discuss, debate, and advance the science of biosignatures. This process will engage a broad range of experts by merging the interdisciplinary reaches of NExSS, the NASA Astrobiology Program (including the Habitable Worlds Program, the NASA Astrobiology Institute, and the Exobiology Program), 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). Between these groups, we will have expertise in astronomy, planetary science, Earth sciences, heliophysics, biology, instrument/mission development, and engineering.

The workshop will gather these communities in the pursuit of 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?

The 3-day in-person workshop will be coordinated with pre-workshop online activities to summarize the state of the science of exoplanet biosignatures. This review will provide background for the in-person workshop, which will focus on advancing the science of biosignatures, and understanding the technological needs and capabilities for their detection. This information will be exchanged with the Science Technology Definition Teams (STDTs) of upcoming planet-observing missions.

The in-person workshop will include plenary talks to set the stage for small group discussions, which will focus addressing key science questions identified by the Science Organizing Committee. The intent is for the workshop to be highly interactive. The meeting agenda will be posted online approximately 1 month prior to the workshop.

Outputs from this workshop will include summary reports, which will be circulated to the community for feedback. These reports will be filed with a dedicated Exoplanet Biosignatures Study Analysis Group (SAG 16) of the Exoplanet Exploration Program Analysis Group (ExoPAG).

Participation is limited to 31-35 in-person attendees in Seattle, but online participants will be unlimited for all activities. To register for either the in-person workshop or as a remote participant, please fill out our survey.


Agenda for Pre-Workshop Online Activities

Start date: June 13, 2016
Meeting time: Meetings will be held twice a week at different times to ensure maximum participation from international participants
Meeting length: 75 minutes

Theme 1: State of the science review

Meeting 1: Topic: Review biosignatures described in Des Marais et al., (2002) Astrobiology 2(2):153-181
Session A (watch archive here): June 13 at 13:00 EDT/17:00 UTC (timed to engage European time zones)
Moderator: Shawn Domagal-Goldman
Speaker: David Des Marais (Slides)
Session B (watch archive here): June 16/17 at 19:00 EDT/23:00 UTC/08:00 am JST (timed to engage Asian time zones)
Moderator: Nikole Lewis
Speaker: David Des Marais (Slides)
Goal/work session: After presentation, fill in rubric recording characteristics of biosignatures described in the review.

Meeting 2: Discuss advances in biosignature research since 2002 review
Session A (watch archive here): June 27 at 13:00 EDT/17:00 UTC
Moderator: Hilairy Hartnett
Speaker: Sarah Rugheimer (atmospheric biosignatures)
Session B (watch archive here): June 30/July 1 at 18:00 EDT/22:00 UTC/07:00 am JST (NOTE: 1 hour earlier!)
Moderator: Nancy Kiang
Speaker: Charles Cockell (surface biosignatures)
Goal/work session: Continue to fill in rubric with published atmospheric and surface biosignature research since 2002.

Meeting 3: Overview of observation technologies
Session A (watch archive here): July 11 at 13:00 EDT/17:00 UTC
Moderator: Maggie Turnbull
Speaker: Karl Stapelfeldt
Session B (watch archive here): July 14/15 at 19:00 EDT/23:00 UTC/08:00 am JST
Moderator: Daniel Apai
Speaker: Drake Deming
Goal/work session: Add observation technology capabilities to the rubric.

Agenda for In-Person Workshop (and Online Broadcast)

Day 1 July 27

  • Breakfast 7:30 - 8:30

  • 8:30 - 11:30 morning session

    • 8:30 - 8:45 Introduction/welcome/agenda overview: Shawn Domagal Goldman and Mary Voytek

    • Advice on how to participate remotely:  Shawn/Mike Toillion

    • 8:45 - 9:30 “Around the room” intros of everyone (90 slots)

      • 30 second voice introduction for in-person attendees, remaining slots for remote attendees

      • Submit 1 Powerpoint slide (use template for same aspect ratio) for book and for video display at venue.

    • 9:30 - 9:45 BREAK

    • Theme 1:  State of the Science Review of Pre-Workshop Online Activities

      • Moderator:  Shawn Domagal-Goldman

      • 9:45 - 10:45 State of the Science - Vikki Meadows (watch video) (Slides)

    • 10:45 - 11:30 Plenary discussion (watch video)

  • 11:30 - 12:30 Lunch

  • 12:30 - 4:30 Afternoon session

    • Theme 2, Part I:  Advancing the Science of Biosignatures (watch video)

      • 12:30 - 12:35: Moderator: Tim Lyons - Geochemical context for rise of O2 (Slides)

      • 12:35 - 1:05: O2 as a biosignature: How likely is it for photosynthesis (especially oxygenic photosynthesis) to evolve? Bob Blankenship (Slides)

      • 1:05 - 1:35: How can we think outside the box and develop alternative atmospheric biosignatures? William Bains (Slides)

      • 1:35 - 2:30: Q&A/Discussion (watch video)

      • 2:30 - 2:45: Instructions for Breakout Groups

      • 2:45 - 3:00: Break

      • 3:00 - 4:30:   Breakout groups I - Frameworks

        • Breakout group I-1

        • Breakout group I-2

        • Breakout group I-3

        • Breakout group I-online: Day 1 Online Breakout Session (watch video)

  • Dinner 6:00 - 8:00


Day 2 July 28

  • Breakfast 7:30 - 8:30

  • 8:30 - 11:30 Morning session

    • Theme 2, Part II:  Advancing the Science of Biosignatures (watch video)

      • 8:30 - 8:35: Moderator: Lee Grenfell

      • 8:35 - 9:05:  Statistical search for life - Sara Walker (Slides)

      • 9:05 - 9:35: How is a biosignature responsive to its environment (chemistry, climate) and geography (distribution)? David Catling (Slides)

      • 9:35 - 10:15:  Q&A/Discussion

      • 10:15-10:30:  Break

      • 10:30 - 11:00  Report-back from Breakout I

      • 11:00-12:30:  Breakout II - Standards

        • Breakout group II-1  

        • Breakout group II-2

        • Breakout group II-3

        • Breakout group II-online

  • 12:30 - 1:30  Lunch

  • 1:30-4:30 Afternoon session

    • 1:30 - 2:30 Report-back from Breakout II (watch video)

      2:30 - 2:45 Instructions for Working Groups (watch video)

    • 2:45 - 3:00 Break and find working group rooms

    • 3:00 - 4:30:  Working groups (for white paper)

      • Working group 1

      • Working group 2

      • Working group 3

      • Working group Online

  • Dinner 6:00 - 8:00


Day 3 July 29

  • Breakfast 7:30 - 8:30

  • 8:30 - 11:30 Morning session

    • Theme 3:   Confidence Standards for Biosignature Observation and Interpretation (watch video)

      • 8:30 - 8:35: Part 3 Moderator: Nick Siegler

      • 8:35 - 9:05:  What can we measure now and in the future? Heike Rauer (Slides)

      • 9:05 - 9:35: Modeling 3-D Planetary Climates as Context for Interpreting Exoplanet Observations - Tony Del Genio (Slides)

      • 9:35 - 10:30: Q&A/Discussion

      • 10:30 - 10:45: Break

    • 10:45 - 12:30: Plenary Activity: What can we measure and/or model? Moderator:  Lee Grenfell (watch video)

  • 12:30-1:30:  Lunch
  • 1:30-2:00: Closing words, instructions for last-day work session, discussion of future work/meetings/goals

  • 2:00 - 4:30: Working groups (for white paper)

    • Working group 1

    • Working group 2

    • Working group 3

    • Working group Online

Presentation File Archive

Download presentation files from the above activities here.
William Bains - "How can we think outside the box and develop alternative atmospheric biosignatures?"
Robert Blankenship - "How likely is it for oxygenic photosynthesis to evolve?"
David Catling - "Metrics to find life from remote sensing data & their limitations"
Tony Del Genio - "Modeling 3-D Planetary Climates as Context for Interpreting Exoplanet Observations"
David Des Marais - "Remote Sensing of Planetary Properties and Biosignatures on Extrasolar Terrestrial Planets"
Tim Lyons - "Some Lessons Learned From Early Earth: the importance of the environmental context"
Heike Rauer - "Biosignatures: What can we measure now and in the future?"
Sara Imari Walker - "Statistical Signatures of Life"

What is NExSS?

NExSS is a coordinating body formed in 2015 whose goal is to foster an interdisciplinary network of researchers spanning astrophysics, heliophysics, planetary science, and the biogeosciences, within the Solar System and beyond, who, through inclusive community activities and cross-discipline collaboration, seek to advance exoplanet science and discovery, and the search for life in the Universe.

This website is being run by Knowinnovation Inc. and is supported by the Lunar and Planetary Institute (LPI). LPI is operated by the Universities Space Research Association (USRA) under a cooperative agreement with NASA. The purpose of this site is to facilitate communication from and between scientists that are part of the Nexus for Exoplanet Systems Science (NExSS). Although NExSS is led by researchers whose funding comes from NASA, NExSS is a community endeavor. As such, any opinions, findings, and conclusions or recommendations expressed on this website are those of the author(s) and do not necessarily reflect the views of NASA.