Edward Anders | |
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Born | Edward Alperovitch June 21, 1926 Liepāja, Latvia |
Nationality | American |
Alma mater | Ph.D., Columbia University, 1954 |
Known for | |
Spouse | Joan F. Anders |
Awards |
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Scientific career | |
Fields | Cosmochemistry |
Institutions |
Edward Anders (born June 21, 1926) is a Latvian-born American chemist and emeritus professor of chemistry at the University of Chicago. His major areas of research have included the origin and ages of meteorites, the existence of presolar grains in meteorites, the solar-system abundance of chemical elements, and mass extinctions in earth history. [2] In the 1970s, he was one of the 142 principal investigators who studied lunar samples brought back to Earth by the Apollo program. [3] After retiring from scientific research in 1991, he became a prominent researcher, speaker and writer on issues related to the Holocaust in Latvia.
Anders was born Edward Alperovitch in the Latvian coastal city of Liepāja in 1926. Both his mother (Erica, née Sheftelovitch-Meiran) and his father (Adolf) were part of a German-speaking Jewish merchant community. In 1940, the Soviet Union occupied Latvia, and in 1941, Latvia was invaded by Nazi Germany. Anders's father was among many Liepaja Jews murdered by the Nazis in the early months of the occupation. Anders and his mother evaded Nazi annihilation by pretending that she was an Aryan foundling raised by Jews, until they were able to flee Latvia near the end of World War II. [4]
After the end of the war, Anders settled in Munich, where he attended first the UNRRA University, a makeshift institution created by the United Nations Relief and Rehabilitation Administration solely to serve refugees, and then the University of Munich. [5] In August 1948, Anders appeared as a prosecution witness at the Nuremberg High Command Trial, where he gave evidence of German soldiers carrying out lootings and shooting Jewish civilians in Liepaja during 1941. [6]
In 1949, Anders arrived in New York City, where he embarked on a master's degree in chemistry at Columbia University. He earned a Ph.D. from Columbia in 1954, benefiting from the mentorship of Columbia nuclear-chemistry professor Jack Malcolm Miller. [7]
Anders spent most of his scientific career on the chemistry faculty at the University of Chicago. He arrived as an assistant professor in 1955, gained tenure a few years later and was named the Horace B. Horton professor in 1973. He spent 1963–64 at the University of Bern as a visiting professor on sabbatical; he returned to the Swiss university for six shorter stays from 1970–1990. His first academic appointment was as an instructor at the University of Illinois (Champaign-Urbana) from 1954 to 1955. [8]
In 1959, Anders won the Newcomb Cleveland Prize from the American Association for the Advancement of Science for his work on meteorites and asteroids. [9] His findings during this period included evidence that meteorites come from the asteroid belt, [10] and an explanation for the ways tiny diamonds could be created in meteorites, without requiring the enormous pressure that could only be found in larger bodies with greater gravitational forces. [11]
In 1973, Anders received the NASA Exceptional Scientific Achievement Medal, [1] acknowledging his work analyzing multiple batches of lunar samples brought back to Earth by the Apollo project. In 1974, Britain's Royal Astronomical Society named him an honorary foreign member, or associate. He also was elected to the U.S. National Academy of Sciences in 1974. [12]
Anders and colleagues began documenting evidence of stardust within meteorites in 1978, publishing findings in Science suggesting that "primitive meteorites contain yet another kind of alien, presolar material: dust grains ejected from red giants." [13] Subsequent research by Anders and coworkers established the presence of diamonds, [14] silicon carbide and graphite in meteorites' interstellar grains. [15] In a 1991 interview with Discover , Anders referred to meteorites as "the poor man's space probe." [16]
In the 1980s, Anders and colleagues published evidence in Science [17] and Nature [18] of catastrophic fires 65 million years ago, caused by a giant meteorite crash in the Gulf of Mexico. Their research on the Cretaceous–Paleogene extinction event analyzed silt sediments from sites as far away as Europe and New Zealand. In each case, they found high amounts of iridium (a rare element associated with certain meteorites) and massive amounts of carbon (associated with global fires) in the same layers. "The first year after the impact was a dramatic and dangerous period for life on Earth," Anders told The New York Times . [19]
In 1989, Anders and Belgian astronomer Nicolas Grevesse published "Abundances of the Elements," [20] a scientific paper cataloging the most reliable estimates to date of meteorite and solar abundances of more than 80 elements, ranging from hydrogen to uranium. Their findings have been cited in more than 11,000 subsequent papers by other scientific researchers, according to Google Scholar. [21]
In 2003, Anders and co-author Juris Dubrovskis published "Who Died in the Holocaust? Recovering Names From Official Records." Their article, which appeared in Holocaust & Genocide Studies, used Latvian, German, Israeli and other records to document the fate of each of Liepaja's 7,140 Jewish residents during Nazi Germany's occupation. Anders and Dubrovskis established that only 208 survived. [22]
In 2004, Latvia's president, Vaira Vīķe-Freiberga, spoke at the dedication of a Holocaust memorial in Liepāja. She closed by saying: "I want to thank the Liepāja Holocaust Memorial Committee, its chairman Mr. Edward Anders, Mr. Vladimirs Bāns, the authors of the project, and all who lent a hand to make this Memorial become reality." [23]
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table. The abundance of an isotope varies from planet to planet, and even from place to place on the Earth, but remains relatively constant in time.
Presolar grains are interstellar solid matter in the form of tiny solid grains that originated at a time before the Sun was formed. Presolar stardust grains formed within outflowing and cooling gases from earlier presolar stars.
Cosmochemistry or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. This is done primarily through the study of the chemical composition of meteorites and other physical samples. Given that the asteroid parent bodies of meteorites were some of the first solid material to condense from the early solar nebula, cosmochemists are generally, but not exclusively, concerned with the objects contained within the Solar System.
The slow neutron-capture process, or s-process, is a series of reactions in nuclear astrophysics that occur in stars, particularly asymptotic giant branch stars. The s-process is responsible for the creation (nucleosynthesis) of approximately half the atomic nuclei heavier than iron.
Orgueil is a scientifically important carbonaceous chondrite meteorite that fell in southwestern France in 1864.
Cosmic dust – also called extraterrestrial dust, space dust, or star dust – is dust that occurs in outer space or has fallen onto Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 μm), such as micrometeoroids. Larger particles are called meteoroids. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust, and circumplanetary dust. There are several methods to obtain space dust measurement.
The interplanetary dust cloud, or zodiacal cloud, consists of cosmic dust that pervades the space between planets within planetary systems, such as the Solar System. This system of particles has been studied for many years in order to understand its nature, origin, and relationship to larger bodies. There are several methods to obtain space dust measurement.
The oldest dated rocks formed on Earth, as an aggregate of minerals that have not been subsequently broken down by erosion or melted, are more than 4 billion years old, formed during the Hadean Eon of Earth's geological history. Meteorites that were formed in other planetary systems can pre-date Earth. Particles from the Murchison meteorite were dated in January 2020 to be 7 billion years old.
Extraterrestrial material refers to natural objects now on Earth that originated in outer space. Such materials include cosmic dust and meteorites, as well as samples brought to Earth by sample return missions from the Moon, asteroids and comets, as well as solar wind particles.
Aluminium-26 is a radioactive isotope of the chemical element aluminium, decaying by either positron emission or electron capture to stable magnesium-26. The half-life of 26Al is 717,000 years. This is far too short for the isotope to survive as a primordial nuclide, but a small amount of it is produced by collisions of atoms with cosmic ray protons.
CI chondrites, also called C1 chondrites or Ivuna-type carbonaceous chondrites, are a group of rare carbonaceous chondrite, a type of stony meteorite. They are named after the Ivuna meteorite, the type specimen. CI chondrites have been recovered in France, Canada, India, and Tanzania. Their overall chemical composition closely resembles the elemental composition of the Sun, more so than any other type of meteorite.
Interstellar ice consists of grains of volatiles in the ice phase that form in the interstellar medium. Ice and dust grains form the primary material out of which the Solar System was formed. Grains of ice are found in the dense regions of molecular clouds, where new stars are formed. Temperatures in these regions can be as low as 10 K, allowing molecules that collide with grains to form an icy mantle. Thereafter, atoms undergo thermal motion across the surface, eventually forming bonds with other atoms. This results in the formation of water and methanol. Indeed, the ices are dominated by water and methanol, as well as ammonia, carbon monoxide and carbon dioxide. Frozen formaldehyde and molecular hydrogen may also be present. Found in lower abundances are nitriles, ketones, esters and carbonyl sulfide. The mantles of interstellar ice grains are generally amorphous, becoming crystalline only in the presence of a star.
Donald Delbert Clayton is an American astrophysicist whose most visible achievement was the prediction from nucleosynthesis theory that supernovae are intensely radioactive. That earned Clayton the NASA Exceptional Scientific Achievement Medal (1992) for “theoretical astrophysics related to the formation of (chemical) elements in the explosions of stars and to the observable products of these explosions”. Supernovae thereafter became the most important stellar events in astronomy owing to their profoundly radioactive nature. Not only did Clayton discover radioactive nucleosynthesis during explosive silicon burning in stars but he also predicted a new type of astronomy based on it, namely the associated gamma-ray line radiation emitted by matter ejected from supernovae. That paper was selected as one of the fifty most influential papers in astronomy during the twentieth century for the Centennial Volume of the American Astronomical Society. He gathered support from influential astronomers and physicists for a new NASA budget item for a gamma-ray-observatory satellite, achieving successful funding for Compton Gamma Ray Observatory. With his focus on radioactive supernova gas Clayton discovered a new chemical pathway causing carbon dust to condense there by a process that is activated by the radioactivity.
This is a glossary of terms used in meteoritics, the science of meteorites.
Ernst Kunibert Zinner was an Austrian astrophysicist, known for his pioneering work in the analysis of stardust in the laboratory. He long had a position in the United States at the Laboratory for Space Physics at Washington University in St. Louis, Missouri, where he had earned his doctorate. He came to the United States in the 1960s for graduate work. In addition, Zinner regularly taught at European universities, and other American institutions.
Although diamonds on Earth are rare, extraterrestrial diamonds are very common. Diamonds small enough that they contain only about 2000 carbon atoms are abundant in meteorites and some of them formed in stars before the Solar System existed. High pressure experiments suggest large amounts of diamonds are formed from methane on the ice giant planets Uranus and Neptune, while some planets in other planetary systems may be almost pure diamond. Diamonds are also found in stars and may have been the first mineral ever to have formed.
CM chondrites are a group of chondritic meteorites which resemble their type specimen, the Mighei meteorite. The CM is the most commonly recovered group of the 'carbonaceous chondrite' class of meteorites, though all are rarer in collections than ordinary chondrites.
Gas-rich meteorites are meteorites with high levels of primordial gases, such as helium, neon, argon, krypton, xenon and sometimes other elements. Though these gases are present "in virtually all meteorites," the Fayetteville meteorite has ~2,000,000 x10−8 ccSTP/g helium, or ~2% helium by volume equivalent. In comparison, background level is a few ppm.
Rhonda M. Stroud is a materials physicist and planetary scientist at Arizona State University, where she serves as Director of the Buseck Center for Meteorite Studies. From 1998- 2022, she was a Research Physicist at the United States Naval Research Laboratory, where she led the Nanoscale Materials Section. She is known for her research on nanostructures, including quasicrystals and aerogel, and on the materials that make up comets and cosmic dust. She pioneered the use of focused ion beam technology in the study of meteorites.
Katharina Lodders is a German-American planetary scientist and cosmochemist who works as a research professor in the Department of Earth and Planetary Sciences at Washington University in St. Louis, where she co-directs the Planetary Chemistry Laboratory. Her research concerns the chemical composition of solar and stellar environments, including the atmospheres of planets, exoplanets, and brown dwarfs, and the study of the temperatures at which elements condense in stellar environments.