College of Arts and Sciences|Astronomy|Astrobiology

Astrobiology Colloquium Frankie Pavia Presenting

Tuesday, Apr 7, 2026, 3 – 4 p.m.

Title: Using cosmic dust to understand sea ice, ice melt, and polar biogeochemistry

Abstract: Connections between ice coverage shifts and marine productivity in the Arctic are difficult to discern using short instrumental records spanning only decades. The geologic past holds clues that could unlock these connections, but existing mechanisms to reconstruct sea ice coverage and ice melt produce equivocal results. We have developed a new technique to reconstruct ice coverage in the Arctic using the accumulation history of fine-grained interplanetary dust particles, which accrete to Earth’s surface at a constant rate in space and time. During periods of prolonged sea-ice coverage, this cosmic dust is blocked from deposition at the seafloor. We will present results from cosmic dust-based sea-ice reconstructions in combination with reconstructions of surface nutrient utilization by Arctic phytoplankton to deduce future controls on Arctic marine productivity under conditions of sea-ice decline.

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Online Meeting Link: uw.hosted.panopto.com…
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics

Astrobiology Colloquium Jordyn Robare

Tuesday, Apr 14, 2026, 3 – 4 p.m.

Title: From Earth to Enceladus: Using Chemical Thermodynamics to Explore the Relationship between Life and Environment

Abstract: Life relies on materials and energy from the environment, and the transfer of this energy to organisms can be quantified by thermodynamic modeling. I explored this relationship across several systems. First, I quantified energy supplies available to microorganisms in Yellowstone National Park (YNP) hot springs. Using geochemical data from 959 samples collected over more than 20 years, I calculated affinities of 111 redox reactions and found that 67 can supply energy to microorganisms. Aerobic ammonia and sulfide oxidation offer the highest energy supplies park-wide, followed by ferrous iron oxidation at low pH. On the demand side, I built propfit, an open-source Python package that estimates thermodynamic properties of organic molecules ranging from simple solutes to complex membrane lipids. From Yellowstone samples, I identified several membrane-spanning bacterial lipids previously undescribed in hot springs, whose methylation patterns correlate strongly with pH. Finally, I applied affinity calculations to hypothetical organic synthesis reactions in the plumes of Saturn's moon Enceladus, suggesting that the sign of reaction affinities can distinguish plausibly abiotic molecules from potentially biotic ones. I am currently extracting lipids from drill core samples from Atlantis Massif near the Lost City Hydrothermal Field.

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics

Astrobiology Colloquium Andrew Fountain

Tuesday, Apr 21, 2026, 3 – 4 p.m.

Title: Cryoconite Holes - A refugia in icy environments.

Abstract: Cryoconite holes are water-filled cylindrical shaped depressions in glacier ice that provide a habitat for microorganisms. Solar radiation preferentially heats sediment patches residing on a glacier, which then melts the underlying ice creating a depression. The solar heated sediment maintains the water phase throughout the summer. The sediment (and biota) is typically wind transported and sourced from the soils surrounding the glacier. Although cryoconite holes are common to all glaciers, those in the McMurdo Dry Valleys, Antarctica are unique in that they are ice-capped and isolated from the atmosphere. These entombed habitats can survive as such for as much as a decade and develop unusual chemistries. This presentation will emphasize the physical aspects of cryoconite formation and evolution, and summarize some of the chemical and biological characteristics.

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics

Astrobiology Colloquium Don Brownlee

Tuesday, Apr 28, 2026, 3 – 4 p.m.

Title: The composition of habitable terrestrial planets

Abstract: Earth, the only proven habitable planet, was assembled by the rapid accretion of large planetesimals in the early solar system. Although many rocky exoplanets might be similar to Earth, the composition of our planet varies from all other solid solar system bodies including the asteroids and comets. It is reasonable to expect that rocky exoplanets may differ from each other in ways that may influence their longterm habitability.

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics

Astrobiology Colloquium Research Rotations An Li and Morgan Raimondo

Tuesday, May 5, 2026, 3 – 4 p.m.

An Li
Title: Tale of two sugars: trehalose and hyaluronic acid in a frozen Enceladus-analog brine

Abstract: Erupting from a subsurface ocean, the plumes of Enceladus are composed of flash-frozen ice grains composed of varying amounts of salts and organics. How the organics within these plumes partition during freezing relative to the salts and ice grains is not fully understood. While prior works have focused on amino acids and chondritic organics in analog frozen brines for Enceladus and Europa, more complex molecules such as sugars have not been studied. Here we evaluate the hydrophilic sugars trehalose and hyaluronic acid using micro-Raman imaging. We conducted flash-freezing and slow-freezing experiments of these sugars in an analog Enceladus brine made of NaCl, Na2CO3, NH4Cl, and KCl. Raman maps revealed that in both freezing scenarios, trehalose and hyaluronic acid have similar spatial distributions to those of the salt minerals natron (Na2CO3•10H2O) and hydrohalite (NaCl•2H2O). This demonstrates that the solute-solute interactions between the sugars and salts dominate so that the salts concentrate the sugars, despite the hydrogen bonding capabilities of both sugars. Due to the preferential spatial association of organics with salts, future missions should prioritize Type III, salt-rich grains, from the Enceladus plumes as prime candidates for biosignatures.

Morgan Raimondo TBD

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics

Astrobiology Colloquium Research Rotations Patrick Monreal

Tuesday, May 12, 2026, 3 – 4 p.m.

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics

AbSciCon 2026

Sunday, May 17, 8 a.m. – Friday, May 22, 2026, 5 p.m.

Event interval: Single day event
Accessibility Contact: Liza Young
Event Types: Conferences

Astrobiology Colloquium TBD

Tuesday, May 26, 2026, 3 – 4 p.m.

Event interval: Single day event
Campus location: Physics-Astronomy Auditorium (PAA)
Campus room: PAA A102
Accessibility Contact: Liza Young
Event Types: Academics