4th Nassau Mössbauer symposium analysis and summary.- Scientific legacy of Stanley Ruby.- Mössbauer spectroscopy methodology at the cutting-edge of high-pressure research.- Vibrational dynamics of Fe in amorphous Fe-Sc and Fe-Al alloy thin films.- Nuclear Resonance Vibrational Spectroscopy (NRVS) of Fe-S model compounds, Fe-S proteins, and nitrogenase.- On Spin Hamiltonian fits to Mössbauer spectra of high-spin Fe(II) porphyrinate systems.- Mössbauer effect of 151Eu in europium salen complex nanoparticles.- Velocity scales for Mars Mössbauer data.- Nanowires of iron oxides embedded in SiO2 templates.- Nuclear forward scattering vs. conventional Mössbauer studies of atomically tailored Eu-based materials.- A complete solution to the Mössbauer problem, all in one place.- Anisotropic contributions to the transferred hyperfine field studied using a field-induced spin-reorientation.- Use of Mössbauer spectroscopy to determine the effect of salinity on the speciation of triorganotins in Anacostia River sediments.- 57Fe Mössbauer spectroscopic study of (25?x)MnO-xZnO-15Fe2O3-60B2O3 glasses.- Studying surfaces and thin films using Mössbauer spectroscopy.- Variations of BaSnF4 fast ion conductor with the method of preparation and temperature.- The Mössbauer community in the USA.- Two earth years of Mössbauer studies of the surface of Mars with MIMOS II.