PSAS: Andrew Mullen: Microscopes for Earth and Space Exploration
A microscope for life detection is a top candidate instrument for ocean world and other planetary missions. Microscopes developed for ocean, earth, and space exploration have significant overlap; with analog terrestrial environments offering excellent settings to test techniques potential for space application.
In this talk I will introduce basic principles of microscopic imaging and discuss the application of microscopes for life detection and environmental exploration. I will then present several different microscopic imaging systems developed for both oceanographic exploration and planetary missions. This will include details on a submersible digital holographic microscope (DHM) being developed for the underwater robot Icefin, results from benthic underwater microscopes used to observe seafloor organisms, and towed systems for imaging plankton. At then end of this talk I hope you will have a better understanding of the capabilities of microscopes, their history of use in space and ocean applications, and future potential.
PSAS: Chris Carr: Ladder of Life Detection in Three Acts
Georgia Tech astrobiologists develop COVID-19 test kit
Nadia Szeinbaum is featured in NPP newsletter
R. F. Rosenzweig – Virtual Seminar – May 22
ExplOrigins & Astrobiology Primer Community Review
Speaker: Frank Rosenzweig
Affiliation: Georgia Institute of Technology, Department of Biological Sciences
Date: Friday, May 22, 2020 – 10:00am
Location: BlueJeans
Host: ExplOrigins Group
Title: Microbial adaptation to chronic nutrient limitation
M. Herron – Virtual Seminar – May 15
ExplOrigins & Astrobiology Primer Community Review
Speaker: Matt Herron
Affiliation: Georgia Institute of Technology, Department of Biological Sciences
Date: Friday, May 15, 2020 – 10:00am
Location: BlueJeans
Host: ExplOrigins Group
Informal talk: Multicellularity in green algae
M. Khademian – Virtual Seminar – May 8
ExplOrigins & Astrobiology Primer Community Review
Speaker: Maryam Khademian
Affiliation: University of Illinois, Department of Microbiology
Date: Friday, May 8, 2020 – 10:00am
Location: BlueJeans
Host: ExplOrigins Group
Title: Oxidative Stress in Anoxic Habitats
Abstract: Bacteroides thetaiotaomicron was examined to determine whether its obligate anaerobiosis is imposed by endogenous reactive oxygen species or by molecular oxygen itself. Previous analyses established that aerated B. thetaiotaomicron loses some enzyme activities due to a high rate of endogenous superoxide formation. However, the present study establishes that another key step in central metabolism is poisoned by molecular oxygen itself. Pyruvate dissimilation was shown to depend upon two enzymes, pyruvate:formate lyase (PFL) and pyruvate:ferredoxin oxidoreductase (PFOR), that lose activity upon aeration. PFL is a glycyl-radical enzyme whose vulnerability to oxygen is already understood. The rate of PFOR damage was unaffected by the level of superoxide or peroxide, showing that molecular oxygen itself is the culprit. The cell cannot repair PFOR, which amplifies the impact of damage. The rates of PFOR and fumarase inactivation are similar, suggesting that superoxide dismutase is calibrated so the oxygen- and superoxide-sensitive enzymes are equally sensitive to aeration. The physiological purpose of PFL and PFOR is to degrade pyruvate without disrupting the redox balance, and they do so using catalytic mechanisms that are intrinsically vulnerable to oxygen. In this way the anaerobic excellence and oxygen sensitivity of B. thetaiotaomicron are two sides of the same coin.
Congratulations to our first GT Astrobiology Certificate Recipient, Alex Sessa!
Please join us in congratulating Alex Sessa, the first-ever recipient of a GT Astrobiology Graduate Certificate!
Read Alex’s sci comm project here.
Grad Students Boost Astrobiology Hypothesis Browser
For their semester-long science communication capstone project, fifteen Georgia Tech graduate students enrolled in the Astrobiology Graduate Certificate Program published content for Hypothesis Browser, an online tool for hypothesis-based literature searches, designed to capture the state of knowledge around the science of astrobiology and life detection.
Hypotheses were diverse in scope, ranging from planetary formation, to origins of life, to exoplanets, to icy moons, to the evolution of Earth and life. A full list of hypotheses and webpage links is below.
This project was a collaboration between Georgia Tech Astrobiology Graduate Certificate Program, Graham Lau at Blue Marble Space Institute of Science, and Andrew Pohorille at NASA Ames.
Planetary Formation
Reilly Brennan: Solar System Formation
Origins of Life
Tyler Roche: Information Polymers
Rebecca Guth-Metzler: Nucleobases
Taylor Plattner: Organics at Hydrothermal Vents
Exoplanets
Pengxiao Xu: Gaseous biosignatures on exoplanets
Worlds of the Solar System
Elizabeth Spiers: Europa ice thickness
Evolution of Earth and Life
Maria Catalina Granada: Panspermia
Zijian Li: Manganese and Oxygen Leah O’Rourke: Cretaceous–Tertiary mass extinction