The Sun and the Solar System Commons^™

Periodicities And Plasma Density Structure Of Jupiter’S Dawnside Magnetosphere, Xuanye Ma, A.A. Schok, P.A. Delamere, B. Mino, P.A. Damiano, B. Zhang, A. Sciola

Publications

The ability to quantify variations in magnetic field topology and density within Jupiter’s magnetosphere is an important step in understanding the overall structure and dynamics. The Juno spacecraft has provided a rich data set in the dawnside magnetosphere. The recent Grid Agnostic MHD for Extended Research Applications (GAMERA) global simulation study by Zhang et al. (2021) showed a highly structured plasmadisc with closed magnetic field lines mapping between the outer dawn-tail flank and the high latitude polar region. To test these model predictions, we examined Juno’s magnetic field data and electron/energetic particle data to categorize portions of orbits 1-15 into …

Floating Liquid Droplets On The Surface Of Cryogenic Liquids: Implications For Titan Rain, Kendra Farnsworth, Alejandro Soto, Vincent F. Chevrier, Jordan K. Steckloff, Jason M. Soderblom

Space and Planetary Science Faculty Publications and Presentations

Saturn’s moon, Titan, has a hydrocarbon-based hydrologic cycle with methane and ethane rainfall. Because of Titan’s low gravity, “floating liquid droplets” (coherent droplets of liquid hydrocarbons that float upon a liquid surface) may form on the surface of Titan’s hydrocarbon lakes and seas during rainfall. Floating liquid droplets, however, have not been investigated in the laboratory under conditions appropriate for the surface of Titan (cryogenic, hydrocarbon, liquids). We conducted a set of experiments to simulate methane and ethane rainfall under Titan surface conditions (89–94 K, 1.5 bar nitrogen atmosphere) and find that floating ethane droplets form in a wide range …

Delineating A Stream Network At Gale Crater, Mars, On Arcgis Pro: A Geographic Information Systems Approach, Elpidio Guzman De La Cruz

West Chester University Master’s Theses

The northwestern region of the Gale crater experienced flooding in the past. Delineation of stream networks for the northwestern region of Gale Crater, Mars employing geographic information systems (GIS) techniques is applied. The stream network produced by the algorithm in the study traverses the clay unit in Gediz Vallis, and visual HiRISE imagery analysis correlates with a topologic cross section of an inverted river channel of 750 meters wide and 90 meters deep. HiRISE imagery analysis further confirms a sulfate and clay stratigraphic unit in a stream 125 meters wide and 25 meters deep. Lastly, data smoothing procedures in the …

Ellipses, Leaves, And Solar Crescents, John Adam

Mathematics & Statistics Faculty Publications

No abstract provided.

To The Moon: Strategic Competition In The Cislunar Region, Shawn M. Willis

Faculty Publications

China’s advancing space capabilities, particularly in the cislunar region, call for increased cislunar space domain awareness on the part of the United States. US military and civilian decisionmakers must take into account the full scope of China’s cislunar plans and capabilities as the military builds space strategies and future force designs. The United States must also increase near-term investments that support more robust cislunar space domain awareness.

Probabilistic Short Term Solar Driver Forecasting With Neural Network Ensembles, Joshua Daniell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Commonly utilized space weather indices and proxies drive predictive models for thermosphere density, directly impacting objects in low-Earth orbit (LEO) by influencing atmospheric drag forces. A set of solar proxies and indices (drivers), F_10.7, S_10.7, M_10.7, and Y_10.7, are created from a mixture of ground based radio observations and satellite instrument data. These solar drivers represent heating in various levels of the thermosphere and are used as inputs by the JB2008 empirical thermosphere density model. The United States Air Force (USAF) operational High Accuracy Satellite Drag Model (HASDM) relies on JB2008, and …

The Planets, Reimagined: Translating Science Into Music, Kaitlyn Wincup

Honors Projects

Inspired by Gustav Holst’s The Planets, this project analyzed the qualitative properties of the planets in our Solar System and translated them into a composition, created by Connor Gibbs, to represent an overall aural depiction of each planet. Where Holst created an astrological depiction of each of the planets, this piece is an astronomical depiction that broadens the perspectives of its listeners.

Deciphering Surfaces Of Trans-Neptunian And Kuiper Belt Objects Using Radiative Scattering Models, Machine Learning, And Laboratory Experiments, Al Emran

Graduate Theses and Dissertations

Decoding surface-atmospheric interactions and volatile transport mechanisms on trans-Neptunian objects (TNOs) and Kuiper Belt objects (KBOs) involves an in-depth understanding of physical and thermal properties and spatial distribution of surface constituents – nitrogen (N2), methane (CH4), carbon monoxide (CO), and water (H2O) ices. This thesis implements a combination of radiative scattering models, machine learning techniques, and laboratory experiments to investigate the uncertainties in grain size estimation of ices, the spatial distribution of surface compositions on Pluto, and the thermal properties of volatiles found on TNOs and KBOs. Radiative scattering models (Mie theory and Hapke approximations) were used to compare single …

Orbital Mapping Of Seasonal And Yearly Changes In Co2 And Water Ice On The Southern Polar Cap Of Mars, Victoria Michell Ann Karnes

Graduate Theses and Dissertations

This research exhibits a new foundation for the rates of change in CO2 and water ice on the southern polar cap of Mars, where the annual precipitation cycles are known to fluctuate seasonally between the north and south pole, based on observations from the Compact Reconnaissance Imaging Spectrometer (CRISM). The conventional belief is that both CO2 ice and water ice on the southern polar cap condenses and evaporates over the course of a Martian year (MY), condensing during the Martian spring and summer and evaporating during the Martian fall and winter. With this theory in mind, CO2 and water ice …

Kinetic Modeling Of Ionospheric Outflows Observed By The Visions-1 Sounding Rocket, Robert M. Albarran Ii

Doctoral Dissertations and Master's Theses

Plasma escape from the high-latitude ionosphere (ion outflow) serves as a significant source of heavy plasma to magnetospheric plasma sheet and ring current regions. Outflows alter mass density and reconnection rates, hence global responses of the magnetosphere. The VISIONS-1 (VISualizing Ion Outflow via Neutral atom imaging during a Substorm) sounding rocket was launched on Feb. 7, 2013 at 8:21 UTC from Poker Flat, Alaska, into an auroral substorm with the objective of identifying the drivers and dynamics of nightside ion outflow at altitudes where it is initiated, below 1000 km. Energetic ion data from the VISIONS-1 polar cap boundary crossing …

Understanding The Role Of Magnetic Field Evolution In The Initiation And Development Of Solar Eruptions, Nian Liu

Dissertations

This dissertation aims to understand the initiation and evolution of solar eruptions. The essential science questions to answer include: What is the role of magnetohydro dynamic (MHD) instabilities and magnetic reconnection in triggering and driving eruptions? What are the role of Kink Instability (KI) and Torus Instability (TI) in determining the successful and failed eruptions? What is the thermal behavior of flare precursors in the initiation stage of solar eruptions? Finally, how does the corona magnetic field respond to the flare eruptions? The dissertation mainly includes the following studies.

First, this dissertation presents a multi-instrument study of the two precursor …

Understanding Martian Salts And Their Implications For Liquid Water, Rachel Slank

Graduate Theses and Dissertations

Water is one of the key components for life as we know it. The existence of salts on Mars has been a large contributing factor to the possibility of habitability, due to their ability to allow liquid water to remain stable at colder temperatures. Salts, including perchlorates, chlorates, and chlorides, have been detected by multiple landers, rovers, and orbiters, and are now believed to be ubiquitous on Mars. One of the pathways to liquid brine solutions is through deliquescence. Deliquescence is the transition from a solid salt crystal into an aqueous solution when exposed to a humid atmosphere. This research …

A Comparison Of Relict And Active Terrestrial Patterned Ground As An Analog For Mars, John Paul Knightly Jr.

Graduate Theses and Dissertations

Patterned ground is a ubiquitous landform in periglacial regions of Earth and is also present across the mid to high latitudes of Mars. The association of terrestrial patterned ground to the presence of subsurface water ice in the form of permafrost that develops a seasonal ‘wet’ active layer during the summer thaw prompted further investigation of patterned ground on Mars. The Phoenix spacecraft was sent to the surface of the north polar plains of Mars to investigate an area of patterned ground where water ice was predicted to occur. The confirmation of subsurface water ice at the Phoenix landing site …

Hydroponically Growing A Holistic Superfood Diet For Mars Exploration, Marianna Pezzella, Ruben A. Rosa Polonia

Beyond: Undergraduate Research Journal

In “Hydroponically Growing a Holistic Superfood Diet for Mars Exploration,” Project H.O.M.E. members conducted an experiment to help determine ways to provide future astronauts with a complete, balanced diet on a planet that does not receive as much sunlight as Earth. Sending massive amounts of food into space is incredibly expensive, takes up valuable spacecraft area, and is, overall, not a feasible way to provide astronauts with sustenance. Project H.O.M.E. has thus developed a hydroponic system to evaluate the growth and yield of various superfoods - including Moringa Oleifera, goji berries, and kale - under simulated Mars lighting conditions. Data …

Determining The Sources Of The Zodiacal Cloud Using Relative Velocities Of Dust Particles From High-Resolution Spectroscopy, Philip B. Mann Iii

Beyond: Undergraduate Research Journal

The zodiacal cloud is the Solar System debris disk in which the Earth’s orbit is located. The dust that comprises the cloud comes from cometary, asteroidal, interstellar, and other source populations, but the relative ratios have proven hard to determine. However, asteroidal and cometary particles typically have different types of orbits, with asteroidal particles having more circular and lower inclination orbits than cometary particles. Accordingly, the relative velocities of these groups of particles with respect to Earth are also different, and measurements of these relative velocities can help distinguish between the sources. The spectrum of the zodiacal light contains solar …

Mms Observations Of The Kelvin-Helmholtz Instability And Associated Ion Scale Waves, Rachel C. Rice

Doctoral Dissertations and Master's Theses

The detailed mechanisms coupling the solar wind to Earth's magnetosphere are not yet fully understood. Solar wind plasma is heated non-adiabatically as it penetrates the magnetosphere, and this process must span scale sizes. Reconnection alone is not able to account for the observed heating; other mechanisms must be at work. One potential process is the Kelvin-Helmholtz instability (KHI). The KHI is a convective instability which operates at the fluid scale in plasmas, but is capable of driving secondary process at smaller scales. Previous work has shown evidence of magnetic reconnection, various ion scale wave modes, mode conversion, and turbulence associated …

Untangling The Solar Wind And Magnetospheric Drivers Of The Radiation Belt Electrons, Simon Wing, Jay R. Johnson, Drew L. Turner, Aleksandr Y. Ukhorskiy, Alexander J. Boyd

Faculty Publications

Plain Language Summary

Many solar wind parameters correlate with one another, which complicates the causal-effect studies of solar wind driving of the magnetosphere. We use conditional mutual information, which is part of information theory, to untangle and isolate the effect of individual solar wind and magnetospheric drivers of the radiation belt electrons. For example, the solar wind density negatively correlates with electron phase space density (PSD) (average energy ∼1.6 MeV) with the response time lag of 15 hr. This has been attributed to the electron loss process such as magnetopause shadowing. The time lag suggests the time scale for this …

The Solar Eclipse Of 1869 As Seen In Illinois, Indiana, And Kentucky, Trishyan Anthony

Research in the Capitol

The Solar Eclipse of August 7th, 1869, was the first recorded total eclipse of the Sun to pass over the United States. The altitude of the eclipse varied depending on the longitude of the viewer. Wanting to know what was the public reaction of this solar eclipse gathering newspaper articles of the time really showed a window to what they were seeing and feeling at that time, and leading up to the day. Following the eclipse through some of the Midwest down to Kentucky showed differing results, as it had got later in the day of viewing. Though there was …

Venus Mountain Waves In The Upper Atmosphere Simulated By A Time-Invariant Linear Full-Wave Spectral Model, Michael P. Hickey, Richard L. Walterscheid, Thomas Navarro, Gerald Schubert

Publications

A 2-D spectral full-wave model is described that simulates the generation and propagation of mountain waves over idealized topography in Venus' atmosphere. Modeled temperature perturbations are compared with the Akatsuki observations. Lower atmosphere eddy diffusivity and stability play a major role in the upward propagation of gravity waves from their mountain sources. Two local times (LT) are considered. For LT = 11 h the waves are blocked by a critical level near 100 km altitude, while for LT = 16 h the waves propagate into the thermosphere. As a result of the small scale height in the Venus thermosphere, for …

Coupling Between Alfvén Wave And Kelvin–Helmholtz Waves In The Low Latitude Boundary Layer, Eun-Hwa Kim, Jay R. Johnson

Faculty Publications

The Kelvin–Helmholtz (KH) instability of magnetohydrodynamic surface waves at the low latitude boundary layer is examined using both an eigenfrequency analysis and a time-dependent wave simulation. The analysis includes the effects of sheared flow and Alfvén velocity gradient. When the magnetosheath flows are perpendicular to the ambient magnetic field direction, unstable KH waves that propagate obliquely to the sheared flow direction occur at the sheared flow surface when the Alfvén Mach number is higher than an instability threshold. Including a shear transition layer between the magnetosphere and magnetosheath leads to secondary KH waves (driven by the sheared flow) that are …