LPI Seminar Series
The LPI Seminar Series brings prominent scientists to the LPI to present on a broad array of scientific disciplines that advance our understanding of the solar system. The seminar series, which began in September 1969, has brought many notable contributors from numerous research and academic institutions to the LPI. Seminars are typically held on Thursdays from 3:00-4:00 p.m. CDT, but dates and times are subject to change. All seminars will be held virtually until further notice.
Sign up for LPI Seminars to receive email notifications of upcoming seminars and details on how to join the virtual seminar. For more information, please contact Patrick McGovern (McGovern@lpi.usra.edu) and Sam Crossley (email@example.com).
See also the Rice University Department of Physics and Astronomy Colloquia and the Department of Earth Science Colloquia pages for other space science talks in the Houston area.
Thursday, December 3, 2020 - Virtual, 3:30 PM
Jamie Cook, Goddard Space Flight Center
Seminar Series: Extracting Secrets of the Solar System: Soluble Organic Analysis of Meteorites and Returned Samples
Laboratory analysis of solar system materials, including meteorites and returned samples, provides important information about early solar system chemistry and the potential distribution of the ingredients necessary for life. Meteorites provide samples from diverse parent bodies, while samples returned by space missions represent materials from known parent bodies with the benefits of context and minimal contamination. Targeted laboratory analyses of these samples have identified a wide range of organic compounds, including soluble organics such as amino acids, carboxylic acids, aldehydes, ketones, sugars, nucleobases, hydrocarbons, and more, as well as insoluble macromolecular material. Amino acids are of particular interest to astrobiology because of the role they play in life on Earth. This talk will discuss how soluble organic compounds, especially amino acids, are analyzed in extraterrestrial materials, and how these analyses contribute to our understanding of the origin of life on Earth.
Thursday, December 10, 2020 - Virtual, 3:30 PM
Emilie Dunham, University of California, Los Angeles
Meteoritic Implications for the Galactic Environment of Solar System Formation
The nature of the galactic environment in which our Sun and Solar System formed remains a mystery – did our Sun form in an active region of star formation, or in a quiescent part of the galaxy? The rate of star formation when and where the Sun formed is difficult to constrain using astronomical observations. I will present how we determined a precise star formation rate ~4.5 billion years ago in the vicinity of our nascent Solar System using a short-lived radionuclide (10Be) in ancient meteorite inclusions. We find that the majority of inclusions from a variety of chondrite types (CV3, CO3, CR2, and CH/CB) record a uniform initial 10Be/9Be = 7 × 10−4. These results indicate that our Sun likely formed in an active star forming region, such as a galactic spiral arm, with ~6–7 times higher star formation rate than at present.
To R.S.V.P., visit https://rb.gy/fb5hxh.
Thursday, December 17, 2020 - Virtual, 3:30 PM
Simone Marchi, Southwest Research Institute
Falling Sky: The Hadean and Archean Earth Asteroid Impact Flux
In the aftermath of the giant collision resulting in the formation of the Moon, about 4.5 billion years ago, the Earth experienced a protracted time of bombardment by leftover planetesimals. In this talk I will present a bombardment model of the Hadean Earth (4.5-4.0 Ga) that has been calibrated using existing lunar and terrestrial data. We find that the surface of the Hadean Earth was widely reprocessed by impacts through mixing and burial by impact-generated melt. This model may explain the absence of early terrestrial rocks. Further, I will discuss the effects of collisions on the formation of impact-induced geochemical heterogeneities that could still persist in terrestrial mantle rocks. Finally, I will present a recent model for the Archean (4.0-2.5 Ga) impact flux, and discuss implications for the oxygenation history of Earth’s atmosphere.