Research topics in the space sciences at Washington University cover a broad range, extending the structure of the universe as a whole, to stars, planets, specimens from meteorites, the moon and Earth, and microscopic tracks left by single atoms. These phenomena reveal the development and operation of our broadest surroundings, from the beginning of the universe, through the evolution of stars, the origin of the solar system (some 4.5 billion years ago), the evolution of lunar craters (mostly finished), the evolution of Earth's continents and oceans (still changing), and the theorist's predictions of the future.
The astrophysical environment provides conditions unavailable in the laboratory for grand-scale testing of fundamental laws of physics. Thus, general relativity studies are being made of the large-scale structure of the universe, and nuclear many-body interactions are being examined to model the superdense matter of neutron stars. Some astronomical objects exhibit rapid fluctuations in their outputs of radiation. Among these are recently discovered X-ray sources, the distant and energetic quasars, and BL Lac objects. These are being studied through telescopes with fast electro-optical instruments that measure fluctuations in radiation intensity and polarization that occur in less than one millisecond. New, ground-breaking uses of optical spectroscopy are being employed to determine compositions of distant interstellar gas and dust grains and cometary matter. These studies are complemented by laboratory laser spectroscopic studies of substances of astrophysical interest.
The composition of matter outside our solar system is also being determined by studies of galactic cosmic rays, using electronic equipment suspended from high altitude balloons and placed in orbit on the High Energy Astronomy Observatory, Mission C (HEAO-C) satellite. Compositions are compared with those estimated, in light of theoretical considerations of creation of the chemical elements by nucleosynthesis in stars.
Theoretical studies are being made of the processes that transport individual nuclei through space--galactic cosmic rays, energetic solar flare particles, and the solar wind plasma. The past history of solar and cosmic radiation is being studied through analyses of meteorites and moon samples.
Recently, scientists at the Center have separated and identified individual presolar dust grains that formed around other stars. Much of this work with presolar dust grains has been performed with the help of a one-of-its-kind-microprobe, the NanoSIMS, "the only instrument in the world capable of analyzing cosmic dust particles so small they can't even be seen with the optical microscope ."
Such grains survived the violent processes of solar system formation and were incorporated into certain primitive meteorites. Structural, isotopic, and molecular studies of these particles are giving new insights into nucleosynthesis and stellar evolution.
Compositions of objects within our solar system are being determined through chemical, mineralogical, and isotopic analysis of samples of the Moon, meteorites, and Earth, and of dust collected by U-2 airplane flights and in a space experiment flown for five years on the Long Duration Exposure Facility (LDEF). Analysis techniques include optical microscopy, electron microscopy, neutron activation analysis, atomic absorption spectrophotometry, noble gas mass spectroscopy, and ion microprobe isotopic analysis.