John Armstead Wood | |
|---|---|
| Born | July 28, 1932 |
| Nationality | American |
| Alma mater | Massachusetts Institute of Technology (Ph. D) |
| Known for | Planetary geology |
| Scientific career | |
| Fields | Planetary geologist, Astronomer |
| Institutions | Smithsonian Astrophysical Observatory, Harvard-Smithsonian Center for Astrophysics |
| Doctoral advisor | Gordon J. F. MacDonald |
John Armstead Wood (born 1932 in Virginia, United States) is an American astrophysicist. He earned his undergraduate degree from the Virginia Polytechnic Institute [1] , and a doctorate from the Massachusetts Institute of Technology under Gordon J. F. MacDonald. He then joined the Smithsonian Astrophysical Observatory, which he retired from in 2004. [2] He was elected to the American Academy of Arts and Sciences in 1992. [3] The Hungaria-type asteroid (4736) Johnwood is named in his honor. His papers are archived with the Smithsonian Institution. [4]
Wood's research involved the petrological study of chondritic meteorites towards an understanding of the origin of the Solar System. Wood analyzed lunar samples from the Apollo 11 mission. He presented his results at the first Lunar and Planetary Science Conference in 1970. [5] In the course of his work, he developed models of the Moon's formation and its internal evolution. Wood was an investigator in the RADIG group that specified the entire workflow for the radar science data collected by the Magellan mission to Venus. [6] [7] Wood chaired the Committee on Planetary and Lunar Exploration (COMPLEX) from 1999-2002, [8] [9] under the Space Studies Board of the National Research Council.
In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase.
A lunar meteorite is a meteorite that is known to have originated on the Moon. A meteorite hitting the Moon is normally classified as a transient lunar phenomenon.
Anorthosite is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present.
A planetary core consists of the innermost layers of a planet. Cores may be entirely liquid, or a mixture of solid and liquid layers as is the case in the Earth. In the Solar System, core sizes range from about 20% to 85% of a planet's radius (Mercury).
Harold (Hal) Masursky was an American astrogeologist.
The Genesis Rock is a sample of Moon rock retrieved by Apollo 15 astronauts James Irwin and David Scott in 1971 during the second lunar EVA, at Spur crater on Earth's Moon. With a mass of c. 270 grams, it is currently stored at the Lunar Sample Laboratory Facility in Houston, Texas.
Moon rock or lunar rock is rock originating from Earth's Moon. This includes lunar material collected during the course of human exploration of the Moon, and rock that has been ejected naturally from the Moon's surface and landed on Earth as meteorites.
The Lunar and Planetary Institute (LPI) is a scientific research institute dedicated to study of the solar system, its formation, evolution, and current state. The Institute is part of the Universities Space Research Association (USRA) and is supported by the Science Mission Directorate of the National Aeronautics and Space Administration (NASA). Located at 3600 Bay Area Boulevard in Houston, Texas, the Institute serves as a scientific forum attracting visiting scientists, postdoctoral fellows, students, and resident experts; supports and serves the research community through newsletters, meetings, and other activities; collects and disseminates planetary data while facilitating the community's access to NASA astromaterials samples and facilities; engages and excites the public about space science; and invests in the development of future generations of scientists. The LPI sponsors and organizes several workshops and conferences throughout the year, including the Lunar and Planetary Science Conference (LPSC) held in March in the Houston area.
Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich endmember of the pyrrhotite group. Pyrrhotite has the formula Fe(1-x)S which is iron deficient. As troilite lacks the iron deficiency which gives pyrrhotite its characteristic magnetism, troilite is non-magnetic.
The Lunar Magma Ocean (LMO) is the layer of molten rock that is theorized to have been present on the surface of the Moon. The LMO was likely present on the Moon from the time of the Moon's formation to tens or hundreds of millions of years after that time. The LMO was a thermodynamic consequence of the Moon's relatively rapid formation in the aftermath of a giant impact between the proto-Earth and another planetary body. As the Moon accreted from the debris from the giant impact, gravitational potential energy was converted to thermal energy. Due to the rapid accretion of the Moon, thermal energy was trapped since it did not have sufficient time to thermally radiate away energy through the lunar surface. The subsequent thermochemical evolution of the LMO explains the Moon's largely anorthositic crust, europium anomaly, and KREEP material.
Susan Elizabeth Werner Kieffer is an American physical geologist and planetary scientist. Kieffer is known for her work on the fluid dynamics of volcanoes, geysers, and rivers, and for her model of the thermodynamic properties of complex minerals. She has also contributed to the scientific understanding of meteorite impacts.
Tranquillityite is silicate mineral with formula (Fe2+)8Ti3Zr2 Si3O24. It is mostly composed of iron, oxygen, silicon, zirconium and titanium with smaller fractions of yttrium and calcium. It is named after the Mare Tranquillitatis (Sea of Tranquility), the place on the Moon where the rock samples were found during the 1969 Apollo 11 mission. It was the last mineral brought from the Moon which was thought to be unique, with no counterpart on Earth, until it was discovered in Australia in 2011.
Planetary science is the scientific study of planets, celestial bodies and planetary systems and the processes of their formation. It studies objects ranging in size from micrometeoroids to gas giants, with the aim of determining their composition, dynamics, formation, interrelations and history. It is a strongly interdisciplinary field, which originally grew from astronomy and Earth science, and now incorporates many disciplines, including planetary geology, cosmochemistry, atmospheric science, physics, oceanography, hydrology, theoretical planetary science, glaciology, and exoplanetology. Allied disciplines include space physics, when concerned with the effects of the Sun on the bodies of the Solar System, and astrobiology.
Allan Hills A81005 or ALH A81005 was the first meteorite to be recognised as a lunar meteorite. The meteorite Yamato 791197 was discovered in 1979 but its lunar origin was not recognised until 1984. ALH A81005 was found in 1982 in the Allan Hills at the end of the Transantarctic Mountains, during a meteorite gathering expedition (ANSMET).
James W. Head III is the Louis and Elizabeth Scherck Distinguished Professor of Geological Sciences at Brown University. He studies the roles of volcanism in planetary crusts as well as the geological evolution of Mars, and has served as the investigator on many major international planetary investigation missions.
Sara Samantha Russell is a professor of planetary sciences and leader of the Planetary Materials Group at the Natural History Museum, London. She is a Fellow of the Meteoritical Society and of the Royal Astronomical Society.
Roger Jay Phillips was an American geophysicist, planetary scientist, and professor emeritus at the Washington University in St. Louis. His research interests included the geophysical structure of planets, and the use of radar and gravity to investigate the surfaces and interiors of the planets.
Ghislaine Crozaz is a cosmochemist known for her research on the early history of the solar system through tracking trace elements in meteorites.
Ferroan anorthosite (FAN) is a pristine coarse-grained igneous rock found in the lunar highlands. FANs have a Ca-rich plagioclase composition greater than 90 wt%, with many consisting of an anorthite-content of 99 wt%. The first hand sample of FAN, Sample 15415, was discovered at the Apollo 15 landing site, Hadley-Apennine. FANs were also found at the Apollo 16 landing site, the Descartes Highlands. FANs have been used to give insights into the evolution of the early lunar crust. Wood et al. 1970 first proposed that FANs were the result of the flotation of plagioclase crystals in a lunar magma ocean (LMO). However, Wetherill 1975 suggested that FANs formed due to serial magmatism.
Serial magmatism is a model that requires basaltic magma to erupt and intrude repeatedly into a pre-existing crust. Regarding the Moon, the magma would have been partially melted in the lunar mantle due to heat produced by initial accretion, radioactive elements, and mantle overturn. As the intruded magma cools it differentiates by density, causing heavier materials to sink down into the lunar mantle, and lighter materials to rise to the crust. As each of the materials separate, they create diapirs which then sink or float to their respective positions. As each diapir solidifies, it would constitute that they would all have their own ages and geochemical signature that may allude to when each intrusion formed. This process would cover a primary lunar crust, and leave us with a complex crust where diapirs overlap and may be difficult to unravel.
