This event will feature four short presentations by UW Astrobiology researchers sharing their latest science.

Adriana Gomez-Buckley: The Viral Elevator: Modeling Virus and Bacteria Populations in Europa’s Icy Ocean
The prospect of life on the icy ocean world of Europa is an exciting one. A common theory is that hydrothermal vents could produce the necessary reductants for chemosynthesis to take place on the ocean bottom. We propose a ‘viral elevator’, a mechanism which functions similarly to the ‘viral shunt’ in Earth’s oceans, which could create and shuttle dissolved organic matter (DOM) to the sub-ice ocean layer through viral carriers. Using studies based in Earth’s Arctic sea ice and ocean, we model the virus–bacteria population dynamics on Europa, both within the ice and in the sub-ice ocean layer, and explore the system properties necessary to produce a steady-state system. Our findings suggest that future searches for life on Europa should account for the longevity of viral and bacterial populations in these systems, and motivates the inclusion of viruses in the search for life rather than limiting life detection to bacteria or bacteria-analog organisms.

Greta Shum: Modeling Self-Perpetuated Climate and Forest Expansion
Pollen records show rapid expansion of needleleaf evergreen forest in the North American high latitudes during the mid-Holocene. Using this period as a case study, we explore the possible role of plant-atmosphere feedbacks in accelerating forest expansion in a two-step experimental set-up. Using a simplified reconstruction of this period in CESM, we simulated the climate response to initial forest establishment (in a coupled land-atmosphere experiment) and subsequently applied the modified climate to nearby vegetation (in a land-only experiment) to determine if the initial forest expansion could have led to more favorable growing conditions in the region. We isolated the effect of a forest’s presence on nearby climate, examined consequent local productivity changes for plants relevant to boreal forest succession, and explored the potential effect of improved plant functional type parameterization on forest-climate feedbacks within the model.

Thea Weiss: Becoming a tree in Virtual Reality: Investigating the efficacy of an embodied virtual nature experience to alter psychological and physiological states
To continue the search for evidence of life on Mars, NASA plans to initiate human exploration of the planet as early as 2030. Maintaining astronaut psychological and physiological well-being is critical for the success of any future crewed missions. Research with people in isolated, confined, and extreme (ICE) environments on Earth indicates that these conditions produce acute psychological issues related to stress and negative affect. Given that interaction with nature is effective at reducing stress and improving emotional state, emerging Virtual Reality (VR) technologies offer a potential means for providing simulated nature experiences to those in ICE environments. VR interventions in clinical and experimental settings have proven useful for facilitating behavior change and altering negative emotional states, and promising research indicates that these experiences may be more effective when they are presented with olfactory and haptic sensory input. As a proof of concept, I am investigating the capacity of an embodied Virtual Reality (VR) nature experience to alter people’s psychological, emotional, and physiological state. I am collaborating with the creators of ‘Tree VR’ – an immersive multi-sensory virtual experience premiered at the Sundance film festival wherein participants experience themselves embodied as a simulated Kapok tree in the Amazonian rainforest. Ultimately, with this study I seek to answer two primary research questions: 1) To what extent can an embodied immersive virtual nature experience induce emotion and alter human physiological state? 2) How can simulated embodiment as a tree in virtual reality generate individual perspective shift and promote greater planetary stewardship?

Eric Agol: Precise constraints on the properties of the TRAPPIST-1 planets
Although several terrestrial exoplanets have been detected in the habitable zones of their stellar systems, few of these planets have measured masses and radii. One of the most promising of these systems for planet characterization are TRAPPIST-1 with seven transiting planets which span the habitable zone of their small host star. With multi-year monitoring of the transits with Spitzer and other telescopes, we have measured the planets’ masses, radii and densities with unprecedented precision for small HZ planets. We report their properties as well as forecast the times of transit in order to constrain their atmospheres with JWST.