Cosmochemistry

UCLA cosmochemists seek to understand all aspects of the origin of our solar system, from its connection with the interstellar medium, to the physical and chemical processes that transformed the materials in the cloud of dust and gas surrounding the nascent sun into the building blocks of planets, to the geologic processes on those early planetesimals and their accretion to form Earth. An important goal is to compare the origin of our solar system to astronomical evidence for the ways in which other planetary systems form. In this research, we use sophisticated instrumentation to examine the mineralogy, chemistry, and isotopic composition of all types of extraterrestrial matter, including meteorites, moon rocks, interplanetary dust particles, and (soon) solar matter returned by the Genesis mission. (See page 16 for a list of analytical tools available to cosmochemists at UCLA Earth & Space Sciences.)

UCLA holds a vast meteorite collection—it is the fifth largest in the country. As pieces of asteroids, meteorites are vestiges of the original rocks from which the planets were made. Some components of primitive meteorites witnessed the conditions that prevailed during the earliest stages of solar system formation. Other more evolved objects, such as lunar rocks and igneous meteorites, tell us about the evolution of planetary bodies including Mars and differentiated asteroids.

Recent discoveries to come from the UCLA cosmochemistry program include:

—The likelihood that some primitive objects that found their way into asteroids originated from very close to the sun more than 4.5 billion years ago

—Fragments of meteorites in deep-sea sediments that correlate with mass extinctions on Earth

—The geological evolution of asteroidal bodies

—The heterogeneous accretion of the early solar system

—Improvements in our understanding of the geology of the Moon

—The role that collisions may have played in heating small asteroid-like planetesimals prior to planet formation

More Information

Related Sites:

Learn more: What are Meteorites?

Faculty and Contacts:

Kevin McKeegan,	Professor of Geochemistry
John Wasson,	Professor of Geochemistry and Chemistry
Ed Young,	Professor of Isotope Geochemistry