Astrobiology

The Energetics of Habitability

Energy is required by all living things. Known organisms exhibit two distinct requirements, analogous to the voltage and power requirements of electrical devices, which must be met simultaneously in order to support metabolism. Quantification of these requirements, and of their sensitivity to environmental factors and organismal specifics, establishes energetic boundary conditions on ‘habitability’. These constraints are likely among the chief determinants of the possible distribution of life in the deep subsurface and in other energy-starved systems.

Condensed-phase methane and tropospheric meteorology on Titan

Methane is near its triple point at Titan’s surface. On the icy-cold moon of Saturn this hydrocarbon is a fluid analog of water on Earth. Transitions among the phases of methane give rise to various meteorological phenomena that can intimately link the atmosphere and surface. Despite the evidence for solid and liquid methane in Titan’s atmosphere, spectroscopic retrievals of aerosol haze opacities, cloud properties, and surface reflectivities have not included opacity due to condensed-phase methane.

Hepatitis B Virus. Discovery, the Present, and the Future.

The Trustees of SETI have interesting and varied careers in addition to their activities with the Institute. This is the first in a series of presentations to be given by Board members on their work.

Extremophiles: What it takes for life to survive beyond the home planet

Recently we have come to realize that where there is liquid water on Earth, virtually no matter what the physical conditions, no matter where, there is life.  Environments we previously thought of as having insurmountable physical and chemical barriers to life, such as extremes in temperature, pH, and radiation, are now seen as yet another niche harboring "extremophiles".

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