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The discovery of thousands of exoplanets revealed a huge variety in the sizes, masses, and orbital properties of planets outside of our solar system. I will discuss how the physics of gas accretion, dust-gas interaction, and star-disk-planet interaction can shape the observed diversity, providing explanations for some of the puzzling demographic patterns that have emerged in exoplanet science while placing our solar system in the larger Galactic context.

Planetary atmospheres are not static in time, and the many changes they experience can contribute to making a planet’s surface a more (or less) hospitable place. Interactions between a planet and its host star are especially important. They not only control the temperature of an atmosphere but can also drive atmospheric escape and atmospheric chemistry. In this presentation I describe ongoing efforts to understand what characteristics of a planet and its star, when combined together, allow the planet to retain an atmosphere that might be habitable at the planet’s surface. I’ll describe observations from planets in our solar system that inform this work, relevant modeling and observational efforts, and a team science effort dedicated to answering this guiding question.

Recent advances in Earth observation and computational techniques allow for the rigorous examination of climate and coastal sediment dynamics at scale. Leveraging these novel methods, we investigate how severe storms and oscillations in Earth’s climate affect Great Bahama Bank (GBB), the world’s largest modern isolated carbonate platform. High-fidelity hydrodynamic simulations suggest that a single hurricane has a negligible effect on the broad-scale distribution of sediments on the platform top, which is predominately sculpted by fair-weather conditions. Nevertheless, multi-decadal satellite monitoring intimates that catastrophic hurricanes, when occurring in quick succession, may be responsible for the remobilization of mud months to years after their passage. On longer time scales still, interannual and decadal variations in suspended sediment are linked to windy El-Niño events, tidal-forcing Lunar Nodal Cycles, and the weakening of the Atlantic Meridional Overturning Circulation. Spatial variations abound too. Surprisingly, sediment lofting along the leeward margin is linked to wind, while tide dictates resuspension on the windward margin. Finally, we present evidence others have found in the Holocene sedimentary record of the same climate signals we observe in the modern – linking platform top sediment dynamics to slope sedimentation. In doing so, we shed light on how modern analogues can be used to constrain past climate signals and predict sedimentological responses in the future.

The Juno spacecraft has been orbiting Jupiter since July 2016 and is completing its first extended mission.  My personal list of the five most important things we’ve learned from the Juno mission during its prime and extended missions goes something like this: 1. Jupiter has a fuzzy core. 2. Moist convection really is a dominant feature of Jovian atmospheric dynamics 3. Water seems to be supersolar in abundance, at least down hundreds of bars pressure.  4. Europa has a platypus-shaped crustal melt region. 5. There is an active lava flow at Zal Montes on Io.

The heat flow of a planetary body plays a major role in defining its evolution and current composition, driving processes from internal differentiation during its formation through geological activity at the current time. In this talk, I will describe how the ALMA (sub-)millimeter observatory and the James Webb Space Telescope are shedding light on the heat flow histories of satellites and small bodies. Thermal emission observations of asteroids provide information on the abundance and form of metals (ALMA) and minerals (JWST) on their surfaces. I will present ongoing asteroid programs aimed at providing a more complete compositional picture of asteroid surfaces, with implications for the early heating and differentiation of planetesimals. ALMA can also measure the isotopes of the volatile-forming elements, a key tool for studying the formation and evolution of objects in the Solar System. I will discuss sulfur and chlorine isotopes in the volcanic gasses of Jupiter’s moon Io in particular, and how they place constraints on the tidal heating and volcanism that Io experienced over the age of the Solar System.

Hot Jupiters — giant planets on short-period (< 10 days) orbits around their host stars -- represent the most extreme outcome of planet formation. Even though they were the first type of exoplanet around Sun-like stars to be discovered, their origins remain unclear. One challenge is our limited understanding of hot Jupiter statistics, as most of them were discovered by a heterogeneous collection of ground-based surveys with a variety of biases. NASA's Transiting Exoplanet Survey Satellite, a uniform all-sky transit search, presents the opportunity to revolutionize hot Jupiter demographics by unifying these previous planet searches. Over the past few years, I led the TESS Grand Unified Hot Jupiter Survey to confirm and characterize hundreds of planet candidates from TESS with facilities like Keck and Magellan. I will present the 4-sigma detection of a pile-up in the period distribution, the dependence of hot Jupiter occurrence on host star properties, and new evidence that they are found around a kinematically young galactic population. I will also discuss how our survey is enabling new lines of inquiry including the discovery of giant planets in the galactic thick disk, as well as detailed characterization of benchmark systems to test key physical processes like tidal inflation and orbital decay.

The field of exoplanets is evolving with astronomical speed, with over 6000 exoplanets discovered to date, including many planets that have no counterparts in the Solar System. More recently, the James Webb Space Telescope has revolutionized our understanding of exoplanet atmospheres by delivering unprecedented spectroscopic constraints on their atmospheric compositions.
In this talk, I will talk about my journey as a planetary scientist who started in the lab working with organic materials on Titan, and how I transitioned to working on some fun theoretical problems for exoplanet atmospheres. Specifically, I will discuss how we can use atmospheric composition to understand the nature and potential habitability of temperate sub-Neptunes, planets with sizes ranging between Earth and Neptune, which also represent the most common type of exoplanets discovered to date. I will also highlight my recent work addressing the emerging population of “missing methane” exoplanets.

The early evolution of the Earth-Moon system prescribes the tidal environment of the Hadean Earth and holds the key to the formation mechanism of the Moon. Estimating its early state by backtracking from the present, however, suffers from considerable uncertainties associated with ocean tides. Tidal evolution during the solidification of Earth’s magma ocean, on the other hand, has the potential to provide robust constraints on the Earth-Moon system before the appearance of a water ocean. To this end, it is of vital importance to understand how energy dissipates in a solidifying magma ocean and how tidal dissipation interacts with atmospheric evolution. These issues have turned out to be much more complicated than previously thought, and as it stands, many of the existing variations of the Moon-forming giant impact hypothesis appear to be unable to explain the present-day angular momentum of the Earth-Moon system, calling for further innovative ideas on the formation of the Moon.

Earthquakes occur naturally driven by tectonic processes, but they can also be induced by human activities. In particular, earthquakes induced by extraction or injection of fluids in the subsurface — during gas production, CO2 storage of geothermal operations for example — provide an opportunity to investigate earthquake physics and to test earthquake forecasting models. Our research shows that, in such examples, spatial and temporal variations in seismicity rate can be predicted reliably from stress changes inferred from reservoir operations and surface deformation measurements. These advances can improve methods for time-dependent seismic hazard assessment. However, forecasting individual events remains a major challenge.

Extreme weather and a warming climate can trigger cascading hazards that reshape landscapes and endanger infrastructure. This seminar explores how hydrology, climate, and geomorphology interact to cause or amplify land surface hazards, such as landslides, flooding, and permafrost degradation. By combining hydrologic modeling and remote sensing data, this work enhances understanding of the processes that link surface water, ground ice, and slope stability. The findings highlight the importance of interdisciplinary research in predicting and mitigating climate-related geohazards.

Groundwater renewability is a key factor in managing sustainable water resources in a changing climate. This seminar discusses new insights into groundwater age, flow pathways, and residence times across diverse aquifer systems. By integrating isotopic data and numerical modeling, the analysis reveals how recharge dynamics vary under different hydrogeologic settings. The results underscore the role of geologic structure and climate forcing in controlling groundwater sustainability and inform strategies for water management and policy.

The vast accumulation of carbon in Arctic soils—an estimated 1,700 Pg—has been referred to as a carbon bomb, a sleeping giant, and Pandora’s freezer. These terms all refer to the so-called ‘permafrost–carbon feedback,’ the cascading cycle in which warming temperatures destabilize permafrost soils, liberating large quantities of carbon to the atmosphere and driving further warming. But predicting whether Arctic landscapes will be a net source or sink of carbon requires tracking the transport and fate of the mobilized soil carbon and quantifying the strength of counteracting processes such as enhanced primary productivity of vegetation. I’ll show how the deposits of meandering rivers provide natural landscape-scale experiments that juxtapose frozen and thawed (permafrost and non-permafrost) terrain in the same environment, allowing us to track the changes to soil carbon and biomass reservoirs over timescales of years to millennia. These observations suggest that permafrost thaw may cause some Arctic landscapes to become a net carbon sink rather than a carbon source.

The deep sections of many modern subduction zones release strain through slow slip and tremor (SST), but the structures responsible, deformation mechanisms, and the role of syn-kinematic fluid flow remain hard to resolve from geodetic and seismologic data alone. Exhumed subduction zone rocks, such as those on Syros Island, Greece, provide key insights into the mechanical and hydrologic conditions within the SST source region. In this talk, I will present field-based and microstructural observations that reveal heterogeneity in viscosity, permeability, friction, and mineral fabrics, and discuss how these properties potentially influence deformation styles along subduction interfaces. These rock-based constraints help bridge the gap between geophysical observations and models, shedding light on the physical conditions that govern transitions between stable creep, slow slip, and seismic failure at depth.

Mars’ interaction with the solar wind exhibits a hybrid nature. The Martian magnetosphere, formed through interactions between the solar wind, ionosphere, and crustal magnetic fields, is complex and highly dynamic. While largely induced, it also contains localized regions where strong crustal fields dominate plasma dynamics. Global magnetohydrodynamic (MHD) modeling has become a critical tool for investigating this system and its role in atmospheric escape. Multi-species MHD studies first demonstrated the importance of ion-specific treatment at high spatial resolution, while later work revealed how rotating crustal fields modulate plasma boundaries and ionospheric structure. Applications to extreme events, such as the September 2017 ICME and the December 2022 disappearing solar wind event, highlighted the dynamic response of Mars’ plasma environment to solar wind variations, particularly density changes. This seminar will review advances in global MHD modeling of Mars and discuss their implications for understanding atmospheric escape and developing future space weather forecasting capabilities at the planet.

The Polarimeter to Unify the Corona and Heliosphere (PUNCH) is a constellation of four smallsats launching in Spring 2025 to image the solar corona and solar wind as a single unified system. The four satellites work together to form a single “virtual coronagraph” with a 90° field of view centered on the Sun. One satellite carries a coronagraph (the Narrow Field Imager) that captures the outer corona at apparent distances between 6 solar radii and 32 solar radii from the Sun. The other three carry heliospheric imagers with 42° wide fields of view, extending from 12 solar radii to 180 solar radii from the Sun. All instruments view visible light scattered by free electrons in the corona and solar wind and use linear polarization to generate 3D information about density structures in the plasma. In this talk, I will briefly describe some of the key background science and the mission itself, then discuss the enabling technologies of deep signal separation and polarimetric inversion to reveal 3D structure before presenting and discussing recent data from the constellation and how to obtain the data for your own use.

Space is never empty. Instead, it is filled with high-energy particles originating at the Sun and trapped by Earth’s magnetic field, forming dynamic radiation environments that pose significant risks to satellites, astronauts, and future exploration missions. In this talk, I will discuss the evolution of Earth’s radiation belts during geomagnetic storms, the processes that limit their intensity, and how similar processes may operate under artificially created conditions. I will present recent work on fast plasma processes that substantially alter radiation levels around Earth. My approach integrates data analysis, simulations, and the development of advanced particle detectors derived from technology originally designed at CERN, tailored specifically for space missions. Additionally, I will showcase results from a student-led balloon mission conducted during the most intense geomagnetic storm of the past two decades. 

Earth’s outer radiation belt is a doughnut-shaped region in space, containing stably trapped energetic electrons. Its outer boundary is closely related to the electron isotropy boundary (IB), which separates the outer radiation belt from the isotropic, precipitating electrons found further out, in the tail current sheet. Field-line curvature scattering (FLCS) is believed to play an important role in causing this isotropic electron precipitation and is effective when the electron gyroradius becomes comparable to the field line curvature radius in the equatorial current sheet region. However, the direct and quantitative impact of FLCS in controlling the outer belt electron lifetimes has never been directly assessed. In this talk, I will discuss the role of FLCS in controlling the outer belt electron lifetimes by combining observations and global radiation belt electron simulations. I will also reveal that this simple yet fundamental physical process which has been historically neglected in global radiation belt models, is sufficient to explain the outer electron belt configuration. Our findings transform our understanding of the dominant processes controlling radiation belt dynamics.

Jupiter’s moon Europa is thought to possess a subsurface ocean that could have the right conditions to harbor life. It will be visited by the Europa Clipper mission starting in 2030. To characterize this ocean and answer questions about habitability, the complex and highly variable plasma environment must be accounted for. In this talk, I will introduce a novel machine learning framework, including both forward and inverse modeling, to better understand the environment. Crucially, our model can reproduce the magnetic field, helping us define the depth, salinity, and conductivity of a potential subsurface ocean. These findings benefit both the upcoming missions to Europa and proposed missions to other planetary bodies such as those at Uranus or Neptune.

Magnetic reconnection occurs continuously along long X-lines at the Earth’s magnetopause. The maximum magnetic shear model provides accurate predictions for the locations of these long X-lines for a wide range of upstream solar wind conditions. One of the more perplexing observational results is that these X-lines appear to be stationary, even on the near-flank magnetopause in the presence of significant magnetosheath plasma bulk flow. An alternate possibility is that X-lines form in the location predicted by the maximum magnetic shear model but then immediately propagate with the magnetosheath plasma bulk flow away from this location. If the X-line reformation cadence is high enough and some other conditions are valid, then these multiple propagating X-lines could appear as a single quasi-stationary X-line at the location predicted by the maximum magnetic shear model. Magnetospheric multiscale observations are used to perform initial tests of this alternate possibility. Results from these initial tests show that there may be multiple X-lines near the predicted location of the X-line, and therefore this alternate possibility may have merit. This alternate possibility may have implications for the magnetospheric cusps. Magnetic reconnection at the magnetopause produces distinct energy-latitude ion dispersion features in the cusps. Multiple reconnection X-lines may produce overlapping dispersion features depending on how they are formed. Therefore, under the right solar wind conditions, there may be many instances of overlapping dispersion features. Observations from the Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS) are used to investigate this possibility.

Magnetosphere and ionosphere coupling is largely driven by electromagnetic waves (e.g., Alfven waves) and particle precipitation in the polar cusp and auroral region. This coupling is inherently dynamic, nonlinear, and multiscale. Ionosphere magnetic perturbations (δB) span scales from >1,000 km across the auroral zone—associated with Region-1 and Region-2 field-aligned currents (FACs)—down to <1 km, approaching the electron inertial length and corresponding to fine-scale auroral arcs (~100 m). These smaller scale δB are often linked to inertial Alfven waves that carry parallel electric fields, accelerate electrons, and produce dynamic auroral structures. During geomagnetic storms and substorms, transient currents associated with these small-scale δB can exceed several hundred μA/m2, leading to ionosphere total electron content (TEC) perturbations and plasma irregularities that cause GPS scintillations and disrupt communication. Characterizing these small-scale δB and their space weather effects remains challenging due to Doppler shift from spacecraft motion (~7.8 km/s) and the scarcity of tandem spacecraft observations of electric and magnetic field measurements necessary to distinguish DC and wave components. NASA's TRACERS mission, launched on 24 July 2025, offers new opportunities to investigate these processes. Here we present initial results from TRACERS MAG observations of a coincident small-scale δB and GPS scintillation event.

The Low-Latitude Ionosphere/Thermosphere Enhancements in Density (LLITED) mission consisted of two 1.5U CubeSat to study nighttime ionosphere/thermosphere coupling. Each CubeSat hosts three science payloads: an ionization gauge (MIGSI) to observe neutral density, a planar ion probe (PIP) to observe plasma density, and a GPS radio occultation sensor for observing (CTECS-A) total electron content. The overall mission, from proposal to on-orbit operations and science investigations, has presented a number of challenges often requiring difficult decisions and compromise in order to maximize the science returns. The various orbit and technical difficulties necessitated a modification and reprioritization of LLITED’s science mission objectives. By modifying the mission science goals, prioritizing event-associated observations, and combining data from other missions and observational conjunctions, LLITED provided insightful observations of neutral and plasma density structures and coupling. This presentation will provide an overview of LLITED’s datasets, describe the various on-going studies, and highlight observations of neutral and plasma density structures at high and mid- latitudes, as well as observations of short time stability of small-scale density structures.

Alfvén waves, named after the Nobel laureate Hannes Alfvén, are a fundamental mode in magnetized plasmas. It has long been established that they play a key role in the energy circulation of the magnetosphere-ionosphere (M–I) coupling system. However, their dissipation on meso- and small-scales is much less well understood. Here, we examine how Alfvén waves drive several common meso-scale structures, including the auroral arcs, auroral beads, and the magnetospheric cusp. We find that Alfvén waves, although being the common energy source, are dissipated differently among these structures. In the auroral arcs, Alfvén waves power a quasi-static parallel electric field that accelerates ions away from and electrons toward the ionosphere. In the auroral beads, electrons are accelerated directly by the wave’s own parallel electric field. In the cusp, Alfvén waves significantly energize the outflowing ions, presumably through perpendicular heating. These distinct energy conversion processes we have unveiled are important in understanding the meso-scale M–I coupling on Earth and other planets. Our results also raise important questions for future studies: How are these Alfvén waves generated? What additional dissipation mechanisms may be operating? Why are Alfvén waves dissipated differently, and what are the controlling factors?

High-resolution spectroscopy is essential for resolving fine spectral features that reveal important physical processes in planetary, astrophysical, and heliophysical environments. However, traditional high-R instruments are large, complex, and incompatible with compact or distributed space platforms. We present a new generation of Spatial Heterodyne Spectroscopy (SHS) systems that overcome these limitations through a fully integrated, all-reflective, and monolithic design. Optimized for the FUV/EUV regime (10–200 nm), our SHS architecture delivers resolving powers of R ~20,000–100,000 in a compact form factor (<2U volume, <10 kg), making it ideal for CubeSats, SmallSats, and deep-space missions. We highlight critical system-level innovations, including thermal, optomechanical, and detector interfacing, as well as a validated performance model that includes sensor and electronics noise, optomechancial alignment tolerance, calibration and operation stability. These developments establish SHS as a scalable, high-fidelity spectroscopic solution for the next generation of space science missions.

Astrophotonics is the application of versatile photonic technologies to channel, manipulate, and disperse guided light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. The photonic platform of guided light in fibers and waveguides has opened the doors to next-generation instrumentation for both ground- and space-based telescopes. Utilizing the photonic advantage is a promising approach to massively miniaturize the next generation of spectrographs for ground- and space-based telescopes. I will discuss some of our recent results from our efforts to design and fabricate high-throughput on-chip astrophotonic spectrographs. These devices are ideally suited for enabling exciting science cases, such as measuring exoplanet masses and characterizing exoplanet atmospheres. I will also discuss specific approaches to make this technology science-ready and qualified for the next generation of space missions and potentially, planetary missions.

Surface observations of Saturn’s moon Titan revealed features characterized as dissected, elevated plateaus with high valley density known as labyrinth terrains. Of this terrain class, a subtype referred to as radial labyrinth is described as dome-shaped uplifts with radial channel patterns. Uplift of these radial labyrinths has been explained as cryomagmatic intrusions at the brittle-ductile transition zone. Here we propose an alternative hypothesis, that crustal heterogeneities in Titan’s upper clathrate crust introduce density differentials due to ethane-methane substitution, as ethane-rich liquids percolate into methane clathrate, inducing solid state flow and generating domal topography. This mechanism is analogous to salt tectonics on Earth and has similarly been evoked for dome formation on the dwarf planet Ceres. We show that the elevation and width of the observed radial labyrinths is consistent with domal uplift driven by a hydraulic head within the uppermost portion of Titan’s crust, given a plausible set of elastic parameters for clathrate hydrates. Additionally, the insulating effect of clathrate, combined with partial mixing with water-ice, allows for sufficiently low viscosity for geologic flow: uplift of the domes could have occurred early in Titan’s history, a billion years ago, or could have uplifted within the last 100 Myr during a recent phase of orbital excitation.

In this talk I will share our recently published results on the detection of potential biosignatures within the Neretva Vallis ancient riverbed on Mars, and then extend outward to our efforts to characterize and explore worlds of the outer solar system that harbor contemporary liquid water oceans beneath lithospheres of ice. At least six ice-covered moons of the outer solar system present compelling evidence for subsurface oceans, and thus provide highly compelling targets in our search for life beyond Earth. I will focus on Jupiter’s moon Europa, and detail experiments conducted in my lab that help us better understand Europa’s ocean chemistry and surface morphology. If time permits, I will also provide an overview of missions that will explore these worlds in the coming decades, and describe how exploration of Earth’s ocean and cryosphere is helping to guide our understanding of the potential habitability of these alien oceans.

Martian meteorites provide key information about the geological history of Mars. However, our collection is biased by geologically young samples that are not representative of Mars’ exposed surface, which is dominated by ancient rocks. This generates gaps in our knowledge of Mars’ early evolution. Recently, we discovered that a Martian meteorite, Teghaza 001, is a gabbroic diorite with a crystallization age > 4.1 Ga. In this presentation, I will describe this unique sample, how it compares to other Martian meteorites and igneous rocks studied by rovers, what results imply to our understanding of early Mars differentiation.