Spring 2013

April 5, 2013

Natalie Batalha, NASA AMES Research Center

Title: Kepler: NASA's Exo-earth Census

Twenty years ago, we knew of no planets orbiting other Sun-like stars, yet today, the roll call is nearly 1,000 strong. Statistical studies of exoplanet populations are possible, and words like "habitable zone" are heard around the dinner table. Theorists are scrambling to explain not only the observed physical characteristics but also the orbital and dynamical properties of planetary systems. The taxonomy is diverse but still reflects the observational biases that dominate the detection surveys. We've yet to find another planet that looks anything like home. The scene changed dramatically with the launch of the Kepler spacecraft in 2009 to determine, via transit photometry, the fraction of stars harboring earth-size planets in or near the Habitable Zone of their parent star. Early catalog releases hint that nature makes small planets efficiently: over half of the sample of 2,700 planet candidates discovered in the first two years are smaller than 2.5 times the Earth's radius. I will describe Kepler's milestone discoveries and progress toward an exo-Earth census. Humankind's speculation about the existence of other worlds like our own has become a veritable quest.

April 12, 2013

Donald Lowe, Stanford

Title: Large Meteorite Impacts on the Archean Earth and Their Role in Early Crustal and Surface Evolution

April 19, 2013

Mikhail Kreslavsky, University of California, Santa Cruz

Title: Kilometer-scale Topographic Roughness of the Moon

April 26, 2013

David Deamer, University of California, Santa Cruz

Title: Geochemical Constraints on the Origin of Life

Field studies in hydrothermal environments associated with volcanic activity in Kamchatka, Iceland, Hawaii and northern California have refined our understanding of geochemical conditions related to life's origin. Direct observations of the complexity of such conditions led us to construct a plausible laboratory simulation of similar sites on the prebiotic Earth. When mixtures of amphiphilic compounds and mononucleotides are exposed to such conditions, the organized multilamellar matrix of the amphiphiles guides extensive polymerization of the monomers into RNA-like molecules. I will describe how nanopore analysis with single molecule resolution can be used to detect synthesis of the nucleic acids.

May 3, 2013

Patricia Gregg, Oregon State University

Title: Thermal-mechanical Models of Magma Chamber Pressurization: Investigating Inflation at Santorini Volcano, Greece

May 10, 2013

Tom Greene, NASA Ames Research Center

Title: The New WFIRST Mission Concept: Bigger and Better for Exoplanets

The WFIRST mission is the highest priority large space project recommended by the 2010 Astronomy and Astrophysics Decadal Survey, and it is scheduled to begin development when JWST is nearing launch. It was conceived to conduct wide field, near-infrared surveys for dark energy, exoplanet gravitational microlensing, and general astrophysics using a moderate aperture (~ 1.3-m) telescope. A new version of the mission incorporates a much larger, Hubble-sized (2.4-m) primary mirror recently donated to NASA. A science definition team is now studying this new mission concept, including an optional coronagraphic instrument for exoplanet imaging and spectroscopy. This talk will highlight the microlensing survey, coronagraphic, and other observational capabilities that this new version of WFIRST has to offer for exoplanets.

May 17, 2013

Marina Brozovic, Jet Propulsion Lab, NASA

Title: Radar Observations of Small Asteroids in the Near-Earth Population: 100 m and Below

May 24, 2013

Andy Rathbun, Chevron ETC

Title: Numerical Investigation of the Interplay Between Wall Geometry and Friction in Granular Fault Gouge

May 31, 2013

Zacharie Duputel, Caltech

Title: W-phase Fast Source Inversion for Moderate to Large Earthquakes