Astrobiology

The Atacama Desert (Chile) ranks as the driest desert on Earth, and is considered a good analog to the extremely arid conditions on Mars. Alfonso will show how photosynthetic bacteria in the hyper-arid core of the Atacama are almost exclusively found within hygroscopic salts, which favor the condensation of water at relative humidity levels that otherwise hinder the occurrence of liquid water on the surface. The resulting saturated solutions are challenging to life, but the habitability of some salts is enhanced at temperatures close to the eutectic.

Professor Glaser will show some visual dynamic and static visual illusions and the effects of ethanol and marijuana on these illusions. He will speculate that ET's may experience a different set of illusions related to their own brain structures and functions. Could their language and visual imagery depend on these cerebral features and therefore be difficult for us to "understand" or appreciate? Do you assume in your work that their physics is the same as ours? 

Jets and outflows from young forming stars are among the most spectacular and energetic phenomena in the night sky. They are ubiquitous in star forming regions, and signal the birth of stars like our own. Similar phenomena exist around new higher massive stars, compact objects, and even black holes. They may differ in dynamics, energetics or emission mechanisms, yet they share the striking similarities in their highly-collimated appearance and high-velocity outflowing motion of gas.

Our planetary system formed out of a rotating accretion disk of gas and dust, often called the solar nebula. In the outer disk where temperatures were cold enough to harbor ices and interstellar materials, comet nuclei accreted. Yet, comets also accreted Mg-rich crystalline silicate mineral grains that formed in the hot inner disk close to the young Sun. Hence, cometary Mg-rich crystalline silicates are the touchstone for radial transport of grains that formed in the inner protoplanetary disk out to the comet-forming zone.

Ed & Rusty will respectively give an overview of the challenge of protecting the Earth from asteroid impacts from the perspectives of both the technical capability to deflect them (and provide other mitigation options) and the international political challenge in defining and agreeing to take such actions.

Observations at millimeter/submillimeter wavelengths of various species can be used to trace the cyclic nature of molecular material, specifically carbon-based, throughout stellar evolution. Studies have shown that the carbon isotopic composition of the interstellar medium suggest a strong dependence upon nearby evolved stars and distance to the Galactic center. However, this can also be affected by the chemical composition, carbon-rich or oxygen-rich, and evolutionary status of these old stars.

Pre-photosynthetic niches were meager with productivity << 10^-4 of modern photosynthesis. Serpentinisation, arc volcanism, and ridge-axis volcanism reliably provided H₂. Methanogens and acetogens reacted CO₂ with H₂ to obtain energy and make organic matter. These skills preadapted a bacterium for anoxygenic photosynthesis, probably starting with H₂ in lieu of an oxygen acceptor. Use of ferrous iron and sulphide followed as abundant oxygen acceptors, allowing productivity to approach modern levels.

All material affected by close proximity to large impacts, for example, tektites and microkrystites, is chemically reduced compared with the starting material. In her PhD research, Abby Sheffer demonstrated that this chemical reduction is the inevitable consequence of the high temperature equilibrium between liquid and gas phases in the hot vapor plume. In parallel work on his PhD, Matt Pasek demonstrated that only the reduced form of Phosphorous can participate in aqueous reactions that lead to the precursors of life.

The Drake Equation predicts a positive correlation between a silent cosmos and a tendency for intelligent life to self extinguish. Alternatively, we simply may not be able to detect or recognize intelligence life in the cosmos --or on planet earth. Humpback whales provide interesting test case, as they appear to exhibit high levels of social intelligence. In Alaska, groups of non-kin form large hunting teams with enduring bonds, specialized tasks, tool use, and gender equity. Their haunting songs and social chatter also suggest that an un-deciphered intelligence echoes through our oceans.