L to R: Platinum/chromium ore, xenolith (black-and-green), silver molybdenum ores (2 lighter rocks)
The Division of Physical Sciences incorporates scientists of the Departments of Astrophysics and of Earth and Planetary Sciences. The astrophysicists study the origin and evolution of planets, stars, stellar clusters, and galaxies using ground- and space-based telescopes, supercomputers, and theoretical studies. Main areas of observational research include the study of the structure of globular clusters—some of the oldest objects in the universe—and of colliding stars found at their centers; an all-sky survey to observe fast-moving stars that will identify all nearby stars within 150 light years and reveal the structure of the Galaxy; and the study of novae in galaxies, to better understand the origin of light chemical elements such as carbon, nitrogen, and oxygen.
Theoretical efforts are focused on understanding star formation and its control by supersonic turbulence driven by supernovae; the formation of stellar clusters and massive stars in them, perhaps by stellar collisions; and the formation of galaxies and the results of supernovae in the first galaxies.
Blue stragglers in Globular Cluster 47 Tucanae
The Earth and Planetary scientists investigate the mineral and chemical origins of solar systems, especially the interaction of interstellar dust, gas, and photons; the transformation and aggregation of interstellar dust into larger bodies such as asteroids and meteorites; the seismic and volcanic behavior of Earth; the formation of minerals, gems, rocks, and mineral deposits; and the role and behavior of volatile elements (carbon, chlorine, fluorine, sulfur, and water) during seismicity and volcanism and in the formation of rocks, minerals, gems, and ores.
Some scientific investigations involve theoretical study and computer modeling. Others involve field research in localities such as Africa, Southeast Asia, Europe, Central and North America, and Russia, and the Division’s collections reflect these areas of research concentration.
The staff is responsible for the specimens and intellectual foundations of displays in the Arthur Ross Hall of Meteorites, the Harry Frank Guggenheim Hall of Minerals, and the Morgan Memorial Hall of Gems, and the halls of the Rose Center for Earth and Space.
The mineral corundum (variety ruby) on the mineral scapolite (mizzonite)
The meteorites, minerals and gems, mineral deposits, and petrology collections contain more than 130,000 physical specimens. The astrophysical collection includes more than three terabytes (one terabyte is equal to one thousand gigabytes) of digital data and consists of observations made with the Hubble Space Telescope and major ground-based optical telescopes as well as simulation data from local and remote computational facilities. These collections support displays in the exhibition halls and the research programs of Museum staff and visiting scientists.
The Division’s meteorites, minerals, and gems are ranked among a select group of "world-class" collections. Important specimen sets include the Tiffany-Morgan gem collections and the mineral collections of Charles and Norman Spang, Clarence S. Bement, and William Boyce Thompson. The meteorite collection includes 5,000 specimens, and the recent emphasis of collection has been on scientific diversity. Many of these specimens, including the 34-ton Cape York Meteorite and the famed Willamette Meteorite, are currently on display.
The petrology and mineral-deposit research collections are of global scope and include 20,000 hand samples, drill-core specimens, rock powders, and thin sections of igneous and metamorphic rocks and ores. These collections concentrate on materials that are probes to the constitution of the crust and deep earth, serve as important metallic resources, and/or represent fundamental geologic process. The petrology collection emphasizes mafic, ultramafic, and alkaline rock suites, especially layered mafic intrusions. The mineral-deposit collections include ore and rock sample suites from the major varieties of deposits as classified by Waldemar Lindgren. New initiatives include the acquisition of drill-core collections from major mining operations.
The observational astrophysics collection includes ground- and space-based sections. The ground-based section includes studies of novae and stellar clusters in external galaxies, stars formed from stellar collisions within globular clusters called blue stragglers, and a major all-sky survey for nearby stars and brown dwarfs. The space-based section includes studies of blue stragglers and novae in external galaxies, and also includes studies of novae and stellar clusters in our own galaxy and the final phases of massive stars before exploding as supernovae. With funding from NASA, the Division is building a collection of all Hubble Space Telescope observations of globular clusters with uniform analysis, for use by the astronomical community.
The simulation collection includes results from grid-based simulations and from particle simulations. The grid-based simulation collection includes studies of the structure and dynamics of star-forming interstellar clouds, and the effects of supernovae from starbursts on dwarf galaxies and of planetary impacts—including that of Comet Shoemaker-Levy 9—on Jupiter. The particle simulations involve studies of stellar clusters. New projects under consideration include studies of galaxy formation and stellar cluster formation from the gravitational collapse of interstellar clouds.
Recurring nova T Pyxidis
The Division’s facilities include several laboratories. The Electron Microprobe Laboratory is a joint analytical facility shared with researchers of the Lamont-Doherty Earth Observatory (at Columbia University) and is used to determine chemical compositions of minerals, rocks, meteorites, ores, and experimentally prepared specimens. In the Experimental Petrology Laboratory, natural and synthetic rocks, glasses, and minerals are subjected to temperatures and pressures equivalent to those of Earth’s upper crust, to simulate conditions at which magmas form, volcanoes erupt and degas volatiles, and metallic mineral deposits form.
The FTIR Laboratory is an analytical facility used to measure the water and carbon dioxide abundances of minerals and glasses. The Simulation and Visualization Laboratories involve a local workstation network, including two special-purpose GRAPE-6 supercomputer co-processors that provide over a teraflop of computing power for gravitational interactions between point objects such as stars. The staff also has access to the SGI Onyx computers of the Rose Center, which include 12- and 28- processor machines, and to the Museum’s Intel Linux cluster, which now contains 560 processors. The X-Ray Laboratories are analytical facilities that support the identification of minerals and determination of their crystal structures.