About

Hilairy Hartnett is the Director of the School of Oceanography at the University of Washington. She is a chemical oceanographer with a transdisciplinary approach, focusing her research on field- and laboratory-based studies of carbon and nitrogen cycling, astrobiology and exoplanets, urban biogeochemistry, and geoengineering. Her work aims to understand the conditions that make environments habitable in the broadest sense for organisms ranging from ancient microbes to future humans, spanning from our own seafloor to Ocean Worlds beyond Earth. As director, she strives to enable and support the success of all members of the UW Oceanography community and to advance a strong vision for the future of the school. Her planetary-scale approach bridges astrophysical observations with biogeochemical systems, contributing to the identification of potential habitats on exoplanets.

Research topics

• Geology
• Chemistry
• Organic chemistry
• Astrobiology
• Social Science
• Computer Science
• Astronomy
• Physics
• Inorganic chemistry
• Sociology
• Computer Security
• Mineralogy
• Materials science
• Thermodynamics
• Chemical engineering
• Biology
• Chemical physics
• Computational chemistry
• Environmental science
• Ecology
• Environmental chemistry
• Data science
• Earth science

Selected publications

• Artificial Flooding Leads to Thicker and Brighter Arctic Sea Ice

  Earth s Future · 2025-12-12

  articleOpen access

  Abstract We describe and present results from a 2024/2025 field campaign that is the first to test and observe the impact of flooding and meltwater draining on Arctic sea ice over the winter growth and spring melt seasons. The campaign was conducted in Cambridge Bay, Nunavut, Canada. A 1 by 1 km fieldwork site was used, comprising three control areas, which were never flooded, and eight test areas. In these, flooding treatments were carried out by pumping seawater onto the sea ice. Some test areas were flooded once (in December or January), while others were flooded twice (in December and February, or January and February). The total area flooded was 0.25 . Additionally, one control area was used for a melt pond drainage experiment during spring. By mid May, prior to melt, flooded test areas were up to 32 cm thicker than control areas, with snow cover that was 1–13 cm thinner. Areas flooded twice exhibited greater thickening than those flooded once. During the melt period, sea ice in the flooded areas appeared brighter and showed slower melt rates, remaining thicker than that in the control areas. The drained melt pond site also brightened markedly within 1 week of borehole drilling. Comparison with a historical sea ice thickness record from Cambridge Bay indicates that a 30 cm increase corresponds to roughly the magnitude of long‐term thinning observed over the past 50 years.

  PublisherDOI

• Reassessing the photochemical contribution to Archean Banded Iron Formations

  Chemical Geology · 2025-03-30 · 1 citations

  article
  PublisherDOI

• Organic Compounds as Messengers of Subsurface Habitability

  2024-01-01

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Characterization of sediments by dielectrophoresis – a new tool to explore organic matter-mineral interactions

  2024-01-01

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Imagining Earth Time

  2023-05-03

  book-chapter1st authorCorresponding

  Earth’s deepest history is challenging to study and even harder to imagine because its billion-year timescales are exceptionally difficult to grasp. As humans, our experiences are measured in years and decades, and we are thus inclined to discount the magnitude of slow things. The Earth evolves and transforms in profound ways that are imperceptibly slow and thus require us to to employ our imaginations to perceive might have been. The events of the ancient Hadean, Archean, and Proterozoic Earth paved the way for complex life and provide a touchstone for understanding the future of Earth and other planets.

  PublisherDOI

• Ethene-ethanol ratios as potential indicators of hydrothermal activity at Enceladus, Europa, and other icy ocean worlds

  Icarus · 2023-08-29 · 7 citations

  article
  PublisherDOI

• Mineral Composition Affects Water Vapor Adsorptionin Unsaturated Soils

  2023-01-01 · 1 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Water Vapor Adsorption Provides Daily, Sustainable Water to Soils of the Hyperarid Atacama Desert

  Astrobiology · 2022-09-09 · 9 citations

  articleCorresponding

  Water is necessary for all life on Earth. Water is so critical that organisms have developed strategies to survive in hyperarid environments. These regions with extremely low water availability are also unique analogs in which to study the physico-chemical conditions of extraterrestrial environments such as Mars. We have identified a daily, sustainable cycle of water vapor adsorption (WVA) and desorption that measurably affects soil water content (SWC) in the hyperarid region of the Atacama Desert in southern Perú. We pair field-based soil temperature and relative humidity soil profiles with laboratory simulations to provide evidence for a daily WVA cycle. Using our WVA model, we estimate that one adsorptive period-one night-increases SWC by 0.2-0.3 mg/g of soil (∼30 μm rainfall). We can plausibly rule out other water inputs during our field campaign that could account for this water input, and we provide evidence that this WVA cycle is driven by solar heating and maintained by atmospheric water vapor. The WVA may also serve to retain water from infrequent rain events in these soils. If the water provided by WVA in these soils is bioavailable, it could have significant implications for the microorganisms that are endemic to hyperarid environments.

  PublisherDOI

• Kinetics and Mechanisms of Hydrothermal Dehydration of Cyclic 1,2- and 1,4-Diols

  The Journal of Organic Chemistry · 2022-10-13 · 6 citations

  articleCorresponding

  Hydrothermal dehydration is an attractive method for deoxygenation and upgrading of biofuels because it requires no reagents or catalysts other than superheated water. Although mono-alcohols cleanly deoxygenate via dehydration under many conditions, polyols such as those derived from saccharides and related structures are known to be recalcitrant with respect to dehydration. Here, we describe detailed mechanistic and kinetic studies of hydrothermal dehydration of 1,2- and 1,4-cyclohexanediols as model compounds to investigate how interactions between the hydroxyls can control the reaction. The diols generally dehydrate more slowly and have more complex reaction pathways than simple cyclohexanol. Although hydrogen bonding between hydroxyls is an important feature of the diol reactions, hydrogen bonding on its own does not explain the reduced reactivity. Rather, it is the way that hydrogen bonding influences the balance between the E1 and E2 elimination mechanisms. We also describe the reaction pathways and follow-up secondary reactions for the slower-dehydrating diols.

  PublisherDOI

• Quantifying the extent of amide and peptide bond synthesis across conditions relevant to geologic and planetary environments

  Geochimica et Cosmochimica Acta · 2021 · 20 citations

  • Chemistry
  • Astrobiology
  • Chemical physics
  PublisherDOI

Recent grants

• Biogeochemistry of Desert Crusts: Organic Carbon and Trace Element Dynamics

  NSF · $389k · 2005–2010

Frequent coauthors

• Everett L. Shock

  47 shared

• Ian R. Gould

  Imperial College London

  33 shared

• Lynda B. Williams

  Arizona State University

  29 shared

• Ariel D. Anbar

  University of Louisiana at Lafayette

  23 shared

• Natalie R. Hinkel

  18 shared

• C. M. Lisse

  Johns Hopkins University Applied Physics Laboratory

  15 shared

• Stephen R. Kane

  15 shared

• Steven J. Desch

  Arizona State University

  14 shared

Education

• PhD, Oceanography

  University of Washington