The Petrochemistry of Jake_M: A Martian Mugearite

“Jake_M,” the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the Curiosity rover, differs substantially in chemical composition from other known martian igneous rocks: It is alkaline (&gt;15% normative nepheline) and relatively fractionated. Jake_M is compositionally similar to terrestrial mugearites, a rock type typically found at ocean islands and continental rifts. By analogy with these comparable terrestrial rocks, Jake_M could have been produced by extensive fractional crystallization of a primary alkaline or transitional magma at elevated pressure, with or without elevated water contents. The discovery of Jake_M suggests that alkaline magmas may be more abundant on Mars than on Earth and that Curiosity could encounter even more fractionated alkaline rocks (for example, phonolites and trachytes).</jats:p

Mars’ Surface Radiation Environment Measured with the Mars Science Laboratory’s Curiosity Rover

The Radiation Assessment Detector (RAD) on the Mars Science Laboratory’s Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.</jats:p

Changing the focus on volunteering: an investigation of volunteers’ multiple contributions to a charitable organization

Despite the fact that over half of the people in the US volunteer each year, there is little theoretical or empirical understanding of volunteer performance. In response, this study examined executive-level volunteers’ multiple contributions of personal resources to a national health care advocacy organization. We expected higher contributions when demands from volunteer roles do not exceed desired levels of contribution, interaction with other volunteers is higher, role investments are higher, and motives to join are consistent with organization’s mission. Regression analyses supported the relation of contributions to social interaction, role investments, and volunteer motives. Suggestions for enhancing the level of volunteer contributions to the organization are made. </jats:p

CCDC 1995946–1995948, 2003689, and 2031254: Experimental Crystal Structure Determination

Related Article: Fedor M. Miloserdov, Connie J. Isaac, Madeleine L. Beck, Arron L. Burnage, James C. B. Farmer, Stuart A. Macgregor, Mary F. Mahon, Michael K. Whittlesey|2020|Inorg.Chem.|59|15606|doi:10.1021/acs.inorgchem.0c0168

Advances in satellite oceanography

Progress has been made in the past four years by U.S. scientists in the development and application of active and passive satellite remote sensing techniques to the study of oceanic processes. This report summarizes technical advances and recent applications. Major advances have been made in developing and applying quantitative measurements from active and passive satellite based sensor systems launched in the late 1970's and that proven methodologies now exist to observe sea surface temperature, ocean elevation, ocean color, surface wind stress and waves, and to locate free drifting buoy data collection platforms. Many of the advances in technique and application have occurred using sensors which were experimental, i.e., not part of an operational satellite observing system. Consequently future geophysical application and development of advanced techniques to enhance our understanding of the ocean will probably be limited in the next five years by data availability rather than our knowledge of how to apply given satellite observations