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2011 May 18

Going to Extreme: Life as we know it

4:00pm

Location: 

Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

Jocelyne DiRuggiero (Johns Hopkins University)

Microorganisms have inhabited the Earth for 3.4 billion years of its history, there are essential for the evolution of its minerals, its major geochemical cycles, and its atmosphere, and therefore we cannot consider the evolution of our planet without considering the evolution of its microorganisms. In addition, planets and moons explored thus far harbor extreme environmental conditions where it is more likely to find microorganisms than any other form of life. I will present recent findings on the...

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2011 Apr 20

Metabolism and Motility in Prebiotic Structures

4:00pm

Location: 

Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

Martin Hanczyc (University of Southern Denmark)

Easily accessible, primitive chemical structures produced by self-assembly of hydrophobic substances into oil droplets may result in self-moving agents able to sense their environment and move to avoid equilibrium. These structures would constitute very primitive examples of life on Earth, even more primitive than simple bilayer vesicle structures. A few examples of simple chemical systems are presented that self-organize to produce oil droplets capable of movement, environment remodeling, and primitive chemotaxis....

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2011 Mar 23

Equipping Planets for Life

4:00pm

Location: 

Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

Ralph Pudritz (McMaster University)

The Kepler observatory is driving a major scientific revolution in our knowledge of exoplanetary systems. Among the key results is the discovery that Earth-like planets are reasonably common around a variety of stars. Do such worlds support life as we know it? How are the pre-biotic conditions that may lead to life established on planets? To explore this, I will first review some of the basic physical astrophysical and geophysical processes that build planets and provide them with water and biomolecules such as amino acids. I will...

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2010 Sep 15

Super-Earth & Life: A Fascinating Puzzle

4:00pm

Location: 

Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

Lisa Kaltenegger (Harvard University/CfA/Origins of Life)

The first Super-Earths have recently been discovered. This number will rise significantly when Kepler planetary candidates will be confirmed. We show models for rocky Super-Earth atmospheres and derive detectable spectroscopic features that can indicate habitable environments in transmission and emergent spectra for future space- and ground based telescopes like the James Webb Space Telescope. What does it take for super-Earths to support life? As a specific example, we show under which condition the recently...

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2012 Sep 26

Microbial sulfate reduction as a vehicle for reconstructing Earth's ancient oxygen budgets

4:00pm

Location: 

Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

David Johnston (Harvard University - Dept. of Earth & Planetary Sciences)

The story of Earth’s biological and chemical evolution is locked within the geological record of marine sediments, and deciphering these stories requires a means of accessing and calibrating that information. Of the directly targetable marine sedimentary records, the stable isotopes of sulfur are one of the most powerful tools for paleo-environmental reconstructions. This applicability is rooted in the quantitative linkage to surface oxygen budgets (namely atmospheric O2) and inherent...

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