Date: Monday 05-Feb-2024
Speaker: Ian Wong (NASA GSFC)
Title: Exploring the diversity of small bodies in the Solar System with JWST: Insights into planetesimal evolution past and present
Abstract: The launch of JWST ushered in a new era of observational astronomy. Within our Solar System, the next-generation capabilities of the on-board instruments are providing fresh perspectives into the chemical composition and physical properties of a wide range of targets. A major focus area of observing programs throughout the first year of science operations has been the exploration of small bodies, including near-Earth objects, main belt asteroids, Jupiter Trojans, and Kuiper belt objects. These enigmatic planetesimals are leftover material from the era of planet formation and are key to understanding detailed aspects of planet formation and the various evolutionary processes that have transpired over the past 4.5 billion years. In this talk, I will provide a broad overview of the exciting results that JWST has provided throughout the Solar System in the realm of small body astronomy. I will also discuss future avenues of study, particularly the potential for productive synergies between JWST and upcoming large-scale surveys, such as the Legacy Survey of Space and Time (LSST) at the Rubin Observatory.
Date: Monday 12-Feb-2024
Speaker: Vincent Kofman (NASA GSFC)
Title: Observables of 3 dimensional effects in direct imaging of exoplanets
Abstract: In this talk, I will discuss our recent results investigating the detectability of 3 dimensional effects in exoplanet observations. For this work, we used the Planetary Spectrum Generator, and its GlobES module, which interfaces with global circulation models. Two results are presented. In the first case, we demonstrate the use of the tool and showcase the differences between the 1D and 3D simulations of tidally locked Trappist 1b. Next, I will present our hyper-realistic models of the Earth and the investigation of the detectability of molecular species in the atmosphere. For this work we used a detailed noise models simulating space-based direct imaging concept telescopes (LUVOIR, HWO, HabEx). We show that the addition of clouds enhances the detectability of O2, H2O and O3 in almost all cases.
Date: Monday 19-Feb-2024
Speaker: Cosmo Sikes (UMD)
Title: Remote Sensing and Experimental Investigation of the Spinel-Rich Sinus Aestuum Pyroclastic Deposits
Abstract: The Sinus Aestuum (SA) Dark Mantle Deposit (DMD) is a pyroclastic deposit on the nearside of the moon which displays spectral signatures observed nowhere else on the lunar surface. Although these signatures suggest high abundances of the mineral spinel to be present within the DMD, the composition and formational mechanism of the SA spinel is largely uncertain. In this talk, I discuss various remote sensing and experimental efforts to determine the origin of this unique deposit. Remote sensing is used to map the appearance of spinel within the region in order to investigate notable geologic features and to determine the true extent of the SA DMD. Although comparison between the spectral properties of spinels observed at SA and terrestrial spinels could help determine a composition and origin, terrestrial spectral analogues of lunar spinel compositions are extremely limited. I discuss mechanisms of lunar spinel formation, constrained through various experimental methods, as well as our efforts to produce spinel spectral analogues consistent with lunar compositions.
Date: Monday 26-Feb-2024
Speaker: Jaehan Bae (University of Florida)
Title: Witnessing the formation of giant planets and their moons
Abstract: With over 5,000 exoplanets discovered, it is clear that planet formation is a robust and widespread process. However, the astonishing diversity between observed exoplanetary systems suggests that the physical conditions present during birth of the planets could influence the characteristics and architecture of the planetary systems. The most direct way to test this hypothesis is to detect and characterize young planets at the time they are forming within their birth protoplanetary disks. The task of observing young, forming planets has long been very challenging, but it has finally become possible with increasingly powerful observing facilities and techniques. In this talk, I will (1) introduce recent high-resolution observations of protoplanetary disks, including the on-going ALMA Large Program exoALMA, (2) show how state-of-the-art observations, along with theories and numerical simulations, can help us better understand planet formation processes, and (3) discuss future directions.
Date: Monday 04-Mar-2024
Speaker: Tony Farnham (UMD)
Title: A Tour Through the Aftermath of the DART Experiment
Abstract: The DART mission crashed a spacecraft into an asteroid to prove the concept of using a kinetic impactor to change the trajectory of an object that would otherwise hit the Earth. DART carried a companion smallsat, LICIACube, that was released before the event and obtained images of the aftermath of the impact during its flyby 167 seconds after. We provide a summary of the primary results from the DART experiment and discuss preliminary results from our ongoing three-dimensional analyses of the ejecta and other phenomena observed by LICIACube.
Date: Monday 25-Mar-2024
Speaker: Jordan Stone (US Naval Research Laboratory)
Title: Massive improvements in atmospheric characterization with direct imaging in the ELT era
Abstract: Atmospheric characterization studies of directly imaged planets and brown dwarfs often (nearly always) result in maximum likelihood models for synthetic atmospheres that imply physically implausible (or impossible) bulk structure. These results underscore the challenges faced by models that must account for the many parameters necessary to represent thermal structure, chemistry, and clouds. When best fit atmosphere models require an impossible internal structure, there is a sense of unreliability touching the implied atmospheric parameters. This issue, now persisting in its second decade, continues to undercut confidence in detailed atmospheric characterization, leaving the community unable to generate the constraints necessary to better understand gas-giant atmospheric processes and planet formation. Happily, this problem should be largely or wholly alleviated as the detection space for direct imaging begins to overlap the parameter space of planets and brown dwarfs with dynamical mass measurements. I will emphasize the need for direct imaging thermal and mid-IR instrumentation on the ELTs to provide sensitivity to planets with measured masses, I will discuss LBTI/ALES efforts to observe wide-orbit gas giants with astrometric accelerations reported in the Hipparcos/Gaia catalog of accelerators.
Date: Monday 01-Apr-2024
Speaker: Yaeji Kim (UMD)
Title: Numerical approaches to investigate small bodies’ structure and surface properties with case studies
Abstract: Small bodies can tell us essential information to understand their evolutionary history and advance the history of our solar system. Since the currently available data on small bodies mostly come from ground-based observations and a few space exploration missions, it is a necessary process to infer small bodies’ properties based on limited data. In terms of scientific importance, we mainly focus on developing numerical models to characterize small bodies’ properties on the surface and structure based on their complex dynamics and suggest diverse case studies showing how the numerical models are applied to asteroids and Kuiper-belt objects.
Date: Monday 15-Apr-2024
Speaker: Aarynn Carter (Space Telescope Science Institute)
Title: First Steps into the Era of Exoplanet Imaging with JWST
Abstract: The first two years of JWST operations have demonstrated significant potential for the direct imaging and characterization of exoplanets and their host environments. The exquisite stability and sensitivity of the telescope have enabled us to push through previous limits of ground-based observations, which had historically constrained us to the investigation of ~1000K super-Jupiter mass exoplanets and their brown dwarf analogues. With careful target selection, JWST can probe for ~300K exoplanets, with masses as low as that of Neptune, at ~10 au separations. The detection of these objects spotlights a potential legacy of JWST characterization observations, through which we may understand the physics, chemistry, and structures of cool, low-gravity atmospheres, with energy budgets dominated by their internal heat. In some cases, these objects will represent close analogues to our own Solar System gas giants, at both Myr and Gyr timescales. Entering this unobserved parameter space will also supply our first constraints on the demographics of wide-separation sub-Jupiters. These measurements will help us place our own Solar System in a galactic context, but also inform our understanding of the nature of debris disk structure, and the formation and evolution of gas giant exoplanets. In this talk, I will present a sample of pathfinder observations that have already exercised JWST’s imaging potential, and the insights that they have provided. Additionally, I will describe a selection of approved JWST exoplanet imaging surveys, which are mere months away from taking their first observations, and will likely define the future of JWST exoplanet imaging.
Date: Monday 22-Apr-2024
Speaker: Nicole Schanche (NASA GSFC)
Title: Exploring TESS’ contribution to ground surveys
Abstract: Since its launch over 6 years ago, TESS has played a part in the confirmation of more than 400 planets, and the identification of thousands more candidates. In addition to discovering new objects of interest, TESS has had a major impact for confirmation (or rejection) of transit signals seen from ground-based observatories such as WASP, HATNet, NGTS, SPECULOOS, and more. In this talk, I will explore how TESS has supported past and present exoplanet surveys, with a particular focus on the WASP project. I will highlight several new planets that were discovered by WASP via machine learning, and later confirmed and characterized using TESS.
Date: Monday 06-May-2024
Speaker: Olivier Barnouin (APL)
Title: Comparing the C-type asteroid Bennu to the S-type binary asteroid system Didymos
Abstract: We will review the remote sensing results obtained at the top-shaped asteroid Bennu collected by NASA’s Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft. Likewise, we will explore observations obtained by NASA’s Double Asteroid Redirection Test (DART) spacecraft at the binary asteroid Didymos. We will note similarities and differences between the formation and evolution of the two bodies and assess what these may mean for our broader understanding of the evolution of small (<1km) asteroids in the Solar System.
