Ongoing Work

The Rosetta mission provided an unparalleled dataset that has revolutionized our understanding of comets. However, one of Rosetta’s primary scientific goals—unraveling the mechanisms behind cometary activity—remains unrealized. The sheer volume and complexity of the data, combined with the lack of efficient tools, have made comprehensive analysis challenging. Currently, retrieving all data associated with a specific Region of Interest (ROI) requires manually searching through over 100,000 images—a daunting and time-consuming task. As a result, while some major surface changes have been documented, many significant and subtle changes remain undetected, leaving gaps in our understanding of comet 67P’s evolution. Discovering and characterizing these changes could provide critical insights into the processes driving cometary activity, shedding light on when, where, and how comets erode and their role as time capsules of the solar system’s earliest history.

With no new missions to comets on the horizon, Rosetta’s dataset will remain the cornerstone of cometary science for at least the next decade, if not longer. To fully realize its potential, we are creating open-source tools that enable efficient and comprehensive querying and analysis of all Rosetta data.

• Comet.Photos: A fast and intuitive tool that will allow users to manually select ROIs on the 3D shape model of 67P and retrieve all associated data. Designed to be user-friendly and accessible to those with no prior experience with Rosetta data, Comet.Photos will be particularly effective for preliminary analyses of selected ROIs. A prototype can be found here.

• Rosetta Search and Characterization Tool (RoSCo): Building on Comet.Photos, RoSCo will offer a more robust data search algorithm. It will enable map-projection and overlaying of images for any ROI, allowing detailed mapping and analysis of surface features (see figure below). RoSCo will save feature locations on the shape model, providing a powerful framework for tracking and studying surface evolution.

These tools will pave the way for broader utilization of Rosetta’s dataset, bringing us closer to understanding cometary surfaces and activity with unprecedented clarity. 

Comets are the most primitive objects in the solar system, and hold crucial insights into the early solar nebula. These icy bodies store volatiles that are periodically released, providing a window into their composition and internal processes. Among the various mechanisms of volatile release, outbursts represent the most extreme and energetic events. Such outbursts have been observed across a variety of cometary bodies, including Jupiter-family comets, centaurs, and dynamically new comets. These phenomena occur under a range of conditions: during local night and midday, at perihelion, and even around aphelion. 

The Rosetta mission provided unprecedented observations of comet 67P/Churyumov–Gerasimenko, documenting dozens of outbursts and their locations. Despite these observations, the subsequent effects on the comet’s landscapes have remained unexplored. We are using RoSCo to analyse regions associated with outbursts and document how the surface was effected. These observations will prove critical to follow-up modeling studies that seek to understand the physical release process, and how these most energetic processes shape the long-term evolution of cometary landscapes. 

The Rosetta mission documented hundreds of surface changes on comet 67P, including erosion and deposition of smooth terrains, cliff collapses, and outbursts occurring on yearly to monthly timescales. However, the temporal and spatial distribution of these changes remains poorly understood, limiting our ability to fully interpret the processes driving cometary evolution.

Using RoSCo, we are building a comprehensive, global database cataloging all observed changes across 67P’s surface. This database will link changes to individual cells on the comet’s global 3D shape model. By organizing the data in this structured format, we aim to empower the broader scientific community to conduct detailed analyses of 67P’s activity.

This resource will support a wide range of follow-up studies addressing key post-Rosetta questions, such as constraining 67P’s non-gravitational accelerations, dust-to-ice ratios, mass loss rates, and dynamics. It will also aid in identifying optimal sampling sites for future sample return missions, such as the proposed CAESAR mission. By creating this global database, we aim to unlock new insights into cometary activity and evolution while enabling the next generation of comet science.

Understanding how sediment is transported and redistributed across a comet’s surface is crucial for unraveling the processes driving its evolution. A global sediment budget not only provides insight into erosion, deposition, and activity patterns but also helps constrain key parameters like mass loss rates and surface renewal timescales.

Our previous work developed a technique to create high-resolution topographic maps for comet 67P's surface and provided a sediment budget for the Imhotep region, the largest smooth terrain on comet 67P. While this study offered critical insights, it represents only a fraction of the comet’s surface—over 80% of its smooth terrains remain unaccounted for. Expanding this methodology to the entirety of 67P’s surface is essential to capture a comprehensive picture of sediment dynamics and activity on a global scale.

By scaling this effort, we aim to provide a complete framework for understanding the interplay of surface processes across the comet, informing future modeling studies and supporting mission planning for sample return initiatives.

Using Rosetta’s high-resolution dataset, we are developing a machine learning model to classify and characterize cometary landscapes. Once trained, this model can be applied to data from other comets with surface observations, such as 9P/Tempel 1, 81P/Wild 2, and 103P/Hartley 2, enabling direct comparisons between these bodies.

This approach will bridge the gap between Rosetta’s detailed observations and the lower-resolution data from previous missions, like Deep Impact, EPOXI, Stardust, and Stardust-NExT. By linking 67P’s landscapes and their evolution to other comets, we aim to uncover broader patterns in cometary surface processes. This work will reveal the implications of our understanding of 67P’s evolution for cometary evolution as a whole, offering new insights into the processes shaping these ancient remnants of the solar system.

Cometary smooth terrains are vast sedimentary basins that act as sinks for air-falling sediment, play a critical role in preserving the primitive materials of comets and governing their activity. Observations from Rosetta revealed unexpected and extensive changes within 67P’s smooth terrains, challenging our understanding of how comets erode, how volatiles and dust interact, and how these processes shape cometary nuclei over time.

To address these questions, we are conducting data-driven numerical simulations to test hypotheses on the formation and evolution of smooth terrains (see figure below). Beginning with 67P, we aim to identify the factors controlling sediment accumulation and erosion, focusing on sediment delivery, remobilization, and exit processes. Our models will then be expanded to other comets, such as 9P/Tempel 1 and 81P/Wild 2, to develop a unified framework for understanding smooth terrains across diverse nuclei.

This research has far-reaching implications, informing ground-based observations, future missions like ESA’s Comet Interceptor, and comet surface sample return concepts. Beyond comets, our findings will also provide insights into sediment and volatile interactions on icy moons and small bodies, contributing to a broader understanding of the solar system’s evolution.