Bruce Fegley

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Earth is the one known example of an inhabited planet and to current knowledge the likeliest site of the one known origin of life. Here we discuss the origin of Earth's atmosphere and ocean and some of the environmental conditions of the early Earth as they may relate to the origin of life. A key punctuating event in the narrative is the Moon-forming(More)
PURPOSE We sought to characterize and compare the histopathologic and clinical changes elicited by subdural and depth electrodes in subjects undergoing epilepsy surgery evaluation. METHODS A retrospective review of clinical records, imaging and histopathologic studies of epilepsy surgery cases requiring subdural strips and depth electrodes for(More)
We use thermochemical equilibrium and kinetic calculations to model sulfur and phosphorus chemistry in the atmospheres of giant planets, brown dwarfs, low-mass stars, and extrasolar giant planets (EGPs). The chemical behavior of individual Sand P-bearing gases and condensates is determined as a function of pressure, temperature, and metallicity. Our results(More)
Intense bombardment of the moon and terrestrial planets approximately 3.9-4.0 x 10(9) years ago could have caused the chemical reprocessing of the Earth's primitive atmosphere. In particular, the shock heating and rapid quenching caused by the impact of large bodies into the atmosphere could produce molecules such as HCN and H2CO4 which are important(More)
It is now understood that the accretion of terrestrial planets naturally involves giant collisions, the moon-forming impact being a well-known example. In the aftermath of such collisions, the surface of the surviving planet is very hot and potentially detectable. Here we explore the atmospheric chemistry, photochemistry, and spectral signatures of(More)
would be determined not only by the production, but also by the (hydrolytic) destruction rate of polyphosphate before it could reach the deep ocean. A detailed discussion has to take into account the following considerations (8), among others: Phosphate would condense out of rock vapor after much of the silicate had condensed. So, rock rain would(More)
Sulfurization of meteoritic metal in H2S-H2 gas produced three different sulfides: monosulfide solid solution [(Fe,Ni)1-xS], pentlandite [(Fe,Ni)9-xS8], and a phosphorus-rich sulfide. The composition of the remnant metal was unchanged. These results are contrary to theoretical predictions that sulfide formation in the solar nebula produced troilite (FeS)(More)
The search for rocky exoplanets plays an important role in our quest for extra-terrestrial life. Here, we discuss the extreme physical properties possible for the first characterized rocky super-Earth, CoRoT-7b (Rpl = 1.58 ± 0.10 REarth, Mpl = 6.9 ± 1.2 MEarth). It is extremely close to its star (a = 0.0171 AU = 4.48 Rst), with its spin and orbital rotation(More)
Thermochemical equilibrium calculations of gas abundances and condensation cloud formation are used to model the atmospheric chemistry of Gliese 229B. The calculations, which are analogous to our prior modeling of atmospheric chemistry of the Jovian planets in our solar system, predict the abundances of gases which are potentially observable by Earth-based(More)