Planetary Science Seminar - fall-2022


Studying rocky planet interiors with catastrophically disintegrating exoplanets

Sept. 23, 2022
noon - 1 p.m.
TBD

Presented By:

  • James Owen - Imperial College London
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The Kepler mission discovered a new class of rocky exoplanets: those so highly irradiated that their surfaces are melted, and the rock vapor atmosphere is escaping at such a rate that the planet is destroyed in a few Gyrs. These planets provide a unique opportunity to study their interior compositions by observing the escaping atmosphere. I will discuss the physics of this problem, our efforts to place basic constraints and the future with the James Webb Space Telescope.


Planet Engulfment Detections are Rare According to Observations and Stellar Modeling

Sept. 30, 2022
noon - 1 p.m.
TBD

Presented By:

  • Aida Behmard - CalTech
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Models of dynamical evolution within planetary systems show that numerous planets should be engulfed by their host stars, leading to elemental pollution of the stellar atmospheres. We conducted a Keck-HIRES survey of 36 multi-star systems but found only one where abundance patterns suggest engulfment. I will discuss the data and an explanation for the rarity of engulfment signatures among these systems.


Destruction of Comets

Oct. 7, 2022
noon - 1 p.m.
TBD

Presented By:

  • David Jewitt - UCLA
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Comets live almost forever in the Oort cloud and Kuiper belt but quickly die upon entering the terrestrial planet region.  The reason for their quick demise was long thought to be the depletion of ice by sublimation but this process turns out to be insufficient.  I will discuss the destruction of comets and its implications for the Kuiper belt and Oort populations.


Evolution of the Lunar Dynamo

Oct. 14, 2022
noon - 1 p.m.
TBD

Presented By:

  • Sonia Tikoo - Stanford
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Dynamo magnetic fields are like the heartbearts of planets – invisible, yet detectable signals of activity within a body’s interior.  Remanent magnetism preserved in the lunar crust and paleomagnetic studies of Apollo samples collectively indicate that the ancient Moon likely generated a magnetic field.  However, the paleointensity history, longevity, and underlying driving mechanisms of the lunar dynamo are debated.  Here we discuss the latest developments in our understanding of the Moon’s enigmatic magnetic history.


DEEP: Discovering Thousands of Ultra-Faint Kuiper Belt Objects

Oct. 21, 2022
noon - 1 p.m.
TBD

Presented By:

  • Kevin Napier - University of Michigan
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DEEP is a Kuiper Belt survey that uses digital tracking to reach depths much fainter than the single-exposure limit. In this talk I will present results from 3 years of DEEP data, yielding 2305 single-epoch detections. I use these detections to compute the absolute magnitude distribution of the Cold Classical population, and discuss the implications for the streaming instability model of planetesimal formation.


Exoplanets and the Road to the Radius Gap

Oct. 28, 2022
noon - 1 p.m.
TBD

Presented By:

  • James Rogers - UCLA
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The observed population of small, close-in exoplanets is bifurcated into two distinct types by the so-called ‘radius gap’. In this talk I will discuss the atmospheric processes which may effect such planets and finally lead to the radius gap being carved out, specifically the core-powered mass-loss mechanism and X-ray/EUV photo-evaporation. I will show how one can exploit these mass-loss processes to 'rewind the clock' on planetary evolution, to infer the underlying population at birth.


Protoplanetary disks

Nov. 4, 2022
noon - 1 p.m.
TBD

Presented By:

  • Ellen Price - University of Chicago
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Seminar Description coming soon.

Chondrules

Nov. 18, 2022
noon - 1 p.m.
TBD

Presented By:

  • Devin Schrader - ASU
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Seminar Description coming soon.

TBD

Dec. 2, 2022
noon - 1 p.m.
TBD

Presented By:

  • Adrian Lenardic - Rice University
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Seminar Description coming soon.