Planetary Sciences Division Seminar
Title : Decoding Aqueous Alteration on Mars: Insights from Water/Rock (WR) ratios in Open and Closed Systems
Date : 02-05-2025
Time : 16:00:00
Speaker : Mr Aditya Das
Area : Planetary Sciences Division
Venue : Seminar Room # 113/114 (Thaltej Campus)
Abstract
In this talk, I will discuss how water/rock (WR) ratios under open and closed system conditions shape secondary mineral formation on Mars. For this, I shall be analyzing the secondary minerals on both Martian meteorites and terrestrial analogues (Deccan basalts from the Kutch area), which will help in understanding the geochemical conditions responsible for such alteration processes that will offer fresh insights into past climates and alteration histories on Mars.
Title : Understanding evolution of cometary volatiles
Date : 09-05-2025
Time : 16:00:00
Speaker : Mr Akshat Rawat
Area : Planetary Sciences Division
Venue : Seminar Room # 113/114 (Thaltej Campus)
Abstract
Understanding the evolution of volatiles on the surfaces and subsurfaces of comets is crucial to studying their thermal, chemical, and structural history. This talk will provide an overview of the key physical processes driving volatile sublimation on comets, including heat conduction, sublimation, and gas diffusion through porous subsurface material. I will then discuss previous models of cometary nuclei and comae, highlighting their limitations—such as neglecting long-term thermal evolution, relying on simplified geometries (spherical or quasi-3D), underutilizing recent spacecraft data, and lacking integration between nucleus and coma evolution. Addressing these gaps, my research focuses on developing a model that comprehensively links the cometary surface and subsurface with the cometary atmosphere to study volatile evolution. This includes implementing coupled thermophysical and sublimation modelling across realistic comet geometries to interpret cometary activity better and simulate volatile loss over time—particularly at larger heliocentric distances (>3 AU), where CO and CO₂ dominate over H₂O as primary drivers of activity.
Title : N-Body Integration Model for Dust Dynamics and Flux Estimation in Inner Solar System
Date : 14-05-2025
Time : 11:00:00
Speaker : Ms. Aanchal Sahu
Area : Planetary Sciences Division
Venue : Seminar Room # 113/114 (Thaltej Campus)
Abstract
Interplanetary Dust Particles (IDPs), originating from the Asteroid Belt, Kuiper Belt, Oort Cloud, and comets, are fundamental to many Solar System phenomena such as Zodiacal Light and meteor showers. As these particles spiral inward toward the Sun, their orbits are altered by a complex interplay of gravitational and non-gravitational forces, leading to gradual perturbations in their orbital elements. The mathematical formulation of the force models, orbital perturbation equations, and their impact on dust evolution will be discussed. We utilize and analyse the N-body problem using Everhart’s RA15 version of the RADAU integrator, which is particularly well-suited for handling stiff orbital equations. I will be presenting results highlighting how Mean Motion Resonances (MMRs) facilitate the capture and long-term trapping of dust particles near planets which can alter dust trajectories. Additionally, methodologies for statistical estimation of dust flux on planetary surfaces by analysing the position of dust particles over time during their close encounters with planets will be discussed. The velocity distribution of impacting particles will also be examined to provide a more complete picture of dust-planet interactions.
Title : Investigation of Organic Matter in Differentiated Meteorites: Unveiling Indigenous Origins and Impact Dynamics
Date : 16-05-2025
Time : 16:00:00
Speaker : Ms. Neha
Area : Planetary Sciences Division
Venue : Seminar Room # 113/114 (Thaltej Campus)
Abstract
The nature of organic matter in meteorites provides insights into early solar system chemistry and the evolutionary histories of their parent bodies, reflecting processes from nucleosynthesis and dust formation to planetesimal and planetary development over the last 4.5 billion years. This talk provides an overview of the first detailed investigation into the nature and origin of insoluble organic matter (IOM) in aubrites, a rare class of differentiated meteorites. I will present a multitechnique analysis of IOM in aubrites and enstatite chondrites, aimed at understanding the extent of organic distribution within the protoplanetary disk and the physicochemical processes that offer essential clues to their parent body evolution. In this seminar, I will discuss the spectroscopic analyses of the IOM in aubrites compared with chondrite IOM to understand the structural and molecular heterogeneity in different meteorite classes. Further I will be discussing the microscopic studies of these organics highlighting the different carbon morphologies present in aubrites. The results offer new insights into the complex evolutionary history of aubrite parent bodies and contribute to a broader understanding of organic matter preservation in differentiated planetary materials.