Session 1P
Astronomy and Planetary Science
1:00 PM to 2:30 PM | Moderated by Eric Agol
- Presenter
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- David S (David) Bergsman, Junior, Mechanical Engineering, Chemical Engineering, Computer Science NASA Space Grant Scholar
- Mentor
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- David Catling,
- Session
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- 1:00 PM to 2:30 PM
The degree to which planet’s atmospheric composition is in chemical disequilibrium could be used as a diagnostic for life on exoplanets. For example, gases such as O2 and CH4 should react and take lower energy forms of CO2 and H2O at equilibrium, so their mutual presence in an atmosphere indicates an active supplier of gases and energy that maintains disequilibrium. We seek to distinguish quantitatively between atmospheric disequilibrium caused by volcanic activity, solar radiation, and tidal forces versus disequilibrium from biogenic gases. On Earth, gas release and uptake by the biosphere modulates the levels of all the bulk gases in the air, with the exception of argon. In contrast, a dead planet is expected to have a composition closer to inorganic equilibrium. We calculate the available free energy of various atmospheric compositions by minimizing the Gibbs free energy of these systems. We then compare these available energies to create a metric for the possibility of life. The energy minimization process is carried out computationally, using a planet’s atmospheric composition as input and providing an equilibrium composition as output. We use the Gibbs free energies of formation of the compounds at the desired temperature, which are calculated using a database of thermodynamic polynomials. Based on simplified calculations of planetary atmospheres, we expect to see that the Earth’s atmosphere possesses chemical potential energy some 10^2 to 10^7 greater than in other known planetary atmospheres. Solar system planetary atmospheres and a range of possible concentrations applicable to hypothetical exoplanets will be explored, attempting to discern the validity of the metric while gaining a better understanding of what makes an atmosphere more indicative of biology. The developed metric will give researchers a new method of identifying planets with potential for life when they are discovered.
- Presenter
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- Blake Michael (Blake) Freeman, Senior, Mathematics (Comprehensive), Physics
- Mentor
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- Christopher Wrede,
- Session
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- 1:00 PM to 2:30 PM
Presolar grains are small grains of material, found in meteorites, with isotopic ratios differing from those in the solar system at large. They are believed to have originated from distinct astrophysical events such as novae before the formation of our solar system. A nova is caused by the accretion of hydrogen onto a white dwarf star from a larger neighboring star in a binary star system, which results in a thermonuclear runaway on the surface of the white dwarf that ejects material into space. Novae are currently being modeled on computers using existing experimental data and theory. These calculations predict an isotopic ratio for sulfur-33 (33S) to sulfur-32 (32S) that may be up to 150 times that of the solar ratio. This prediction could allow for clear identification of presolar grains from novae, but is subject to uncertainty due to a lack of data on the main destruction mechanism for 33S in novae, the 33S(p,γ) 34Cl reaction. This is a reaction in which a proton combines with 33S to form an excited state of chlorine-34 (34Cl) that promptly decays to a lower energy state of 34Cl by emitting a gamma ray. We are currently using a Van de Graff accelerator to accelerate protons toward a copper target that is implanted with 33S. The objective of this experiment is to measure the resulting gamma rays to determine the gamma ray branching ratios of resonances pertinent to nova reaction rates. When combined with data from a planned experiment at TRIUMF in Canada this will lead to a more accurate prediction for isotopic ratios of sulfur in presolar nova grains. Additionally our data may contribute to predicting whether or not gamma rays emitted from decay of the 34Cl meta-stable state in nova outflows may be observed by telescopes orbiting the Earth.
- Presenter
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- Thomas Alexander (Thomas) Gomez, Senior, Astronomy, Physics EIP Scholar
- Mentor
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- Bruce Balick,
- Session
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- 1:00 PM to 2:30 PM
In the Milky Way, there are very few planetary nebulae (PNe) known to be in the halo, less than a dozen. Studies of the Andromeda Galaxy have shown that there are more than 700 PNe in the thick disk alone. By analogy, we would expect to find several thousand PNe in the halo. We are using surveys such as SDSS and 2MASS to identify new planetary nebulae candidates at high latitudes in the absence of suitable emission-line imaging surveys. Our recent research shows that it is possible to refine the search using near-infrared colors from 2MASS. Combining 2MASS and SDSS were able to produce several viable candidates. In addition we have started a search for halo PN candidates using a narrowband [OIII] filter and a Sloan g' filter at the 0.5m ARCSAT telescope at APO and the 0.75-melescope at Manastash Ridge Observatory (MRO). Once we identify survey candidates with appropriate broad-band optical and IR colors and morphologies, or identified others with strong [OIII] emission, confirmation spectra will be observed on the Apache Point Observatory (APO) 3.5m telescope. There have been a couple of candidates come out of the SDSS queries, those so far have turned out to be interesting objects.
- Presenter
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- Tia Lee (Tia) Lerud, Senior, Applied & Computational Mathematical Sciences (Engineering & Physical), Statistics Mary Gates Scholar, NASA Space Grant Scholar
- Mentor
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- Erika Harnett,
- Session
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- 1:00 PM to 2:30 PM
Terrestrial magnetic storms can threaten the lives astronauts and inflict costly damage on satellites and earth-based structures leading to communication interruptions, blackouts and environmental hazards. Although they are fairly common, the triggering and development of these space weather events is not well understood. It is thought that magnetic storms are triggered by changes in the solar wind and the interplanetary magnetic field (IMF), but no satisfactory relationship between solar wind / IMF signals and storm characteristics has been developed. To address this issue, statistical analysis and data mining techniques are being used to analyze over ten years of satellite and earth-based data with the intent of developing a system for the classification of terrestrial magnetic storms based on solar wind / IMF conditions and storm characteristics. Results from such data analyses form a preliminary classification system from which a representative sample of events is selected. Each of the sample events is then analyzed using 3D multi-fluid simulations for the purpose of gaining insight into the processes dominating storm onset, and for further refining the preliminary classification scheme. Once developed, this classification scheme can serve as a valuable tool for space weather forecasters.
- Presenter
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- Laura Cristina (Laura) Mayorga, Junior, Astronomy NASA Space Grant Scholar
- Mentor
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- Joshua Bandfield,
- Session
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- 1:00 PM to 2:30 PM
Similar to satellite measurements on Earth, scientists are starting to assemble a multi-annual record of surface and atmospheric temperatures on Mars. By monitoring the Martian atmosphere, it may be possible to provide insight about global climate change and apply those findings to similar problems on Earth. On Mars, the movement of dust is a dominant and dynamic factor that drives both surface and atmospheric temperatures. Using data returned from the Thermal Emission Spectrometer (TES) onboard the Mars Global Surveyor (MGS), we can retrieve atmospheric temperature profiles as well as surface temperatures. By monitoring the global changes over the course of over four Martian years, seasonal and annual differences are mapped and plotted. Our study has found that even after a global dust storm that resulted in significant regional changes in surface albedo, the temperatures and planetary albedo have returned to normal by the next year. This result contradicts work done by earlier studies, whose data was altered by calibration artifacts. The information acquired from the analysis of our data will lead to a better understanding of the magnitude of inter-annual climate variability and its driving factors.
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