Planetary Science Seminar - winter-2025
Volatile Degassing and Thermal History of Lunar Volcanic Glasses
Jan. 9, 2025
noon - 1 p.m.
Slichter Hall # 3853
Presented By:
- Ni Peng - UCLA
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Fire fountain eruptions on the Moon produced pyroclastic deposits containing characteristic glass spherules, green, orange, red, yellow, or black in color. These special specimens have attracted scientists' attention since their return by the Apollo missions due to surface-correlated volatiles and, more recently, high contents of indigenous H2O, F, Cl, and S. In this talk, I synthesize existing data to reconstruct the volatile degassing and thermal history of the Apollo 17 orange glasses.
Discovering small asteroids with WISE data
Jan. 16, 2025
noon - 1 p.m.
Online: https://ucla.zoom.us/j/91711550027
Presented By:
- Emerson Whittaker - UCLA
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Synthetic tracking, involving the shifting and stacking of images, allows for the detection of fainter asteroids than traditional methods by increasing S/N by the square root of the number of frames stacked. We use the synthetic tracking software SALTAD on the WISE spacecraft's W3 images to stack 4 - 9 images in subfields covering nearly the entire sky, where preliminary results suggest we will discover 4,200 - 13,100 asteroids.
Icy pollution of Uranus and Neptune’s atmospheres: influences on thermal evolution and composition
Jan. 16, 2025
noon - 1 p.m.
Online: https://ucla.zoom.us/j/91711550027
Presented By:
- Eva Zlimen - UCLA
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In the Nice model of Solar System formation, Uranus and Neptune undergo an orbital upheaval, sweeping through a planetesimal disk. We find that the ice giants undergo an extreme bombardment event, with collision rates as high as ∼3 per hour assuming km-sized planetesimals, increasing the total planet mass by up to ∼0.35%. I will discuss how the resulting atmospheric enrichment may have impacted the atmospheric composition and thermal evolution of Uranus and Neptune due to the effects of latent heat production and inhibited convection.
Integrating Thermal, Visible, and Spectral Observations to Create a Global Map of Martian Frost
Jan. 23, 2025
noon - 1 p.m.
3853 Slichter Hall
Presented By:
- Serina Diniega - JPL
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The annual cycle of CO2, seasonally moving between atmospheric gases and surface frost, is a dominant driver of Martian atmospheric, landscape, and landform activity. We produced the first global map of the seasonal distribution of CO2 frost through a single Mars year, integrating frost indications in visible (HiRISE/CTX), thermal (MCS/THEMIS), and spectral (CRISM) datasets.
The “solar abundance” problem: Decades of discrepancy, today’s progress and implications for outer solar system origins and habitability
Feb. 6, 2025
noon - 1 p.m.
Slichter Hall # 3853
Presented By:
- Ngoc Truong - SouthWest Research Institute
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The Sun’s heavy element abundances play a critical role in shaping the formation and composition of solar system objects, and as benchmarks for understanding other stars’ elemental compositions. However, a long-standing tension exists between the spectroscopically determined heavy element abundances and helioseismology constraints, often referred to as the 'solar abundance' problem. Recently, spacecraft missions to primitive solar system bodies have uncovered intriguing details about early solar system chemistry. Combined with new data from solar C-N-O neutrino and solar wind measurements, I will describe some recent progress to revise the solar composition and its implications for understanding the origin and potential habitability of outer planetary systems.