The current research focus at the Center is on meteoritics, in particular on presolar grains to understand our parent stars and the history of our Galaxy, and on the delivery history of extraterrestrial matter to Earth through the study of fossil meteorites and micrometeorites found in sediments, and terrestrial impact craters. We also study extraterrestrial samples returned to Earth by the NASA mission Stardust.
Our main research themes:
- Interesting Meteorites
- Presolar Grains
- Extraterrestrial Matter in Earth's Sediments and Impact Craters
- Modern Interstellar Dust
Presolar Grains: What are presolar grains and why do we study them?
Presolar grains are minerals that are older than anything else in our Solar System. They formed before the birth of our Solar System and a small fraction survived in primitive asteroids and comets. We extract presolar grains from fragments of these objects: unaltered meteorites, interplanetary dust particles and comet dust. We separate and isolate presolar grains, study their elemental and isotopic compositions to understand the presolar history of meteoritic matter. The interdisciplinary field of presolar grain research informally also called Astrophysics in the Laboratory is delivering a wealth of information on stars - in particular our parent stars that formed the elements we are made of - and our Galaxy that are not accessible through astronomical observations. One of our main motivations to study presolar grains, a surviving fraction of the source materials of our Solar System, is to improve our understanding of the history of our Galaxy.
This presolar silicon carbide grain is genuine stardust extracted from the meteorite Murchison and formed in the wind of an asymptotic branch giant star more than 4.6 billion years ago. Scanning electron microscope false-color image. © Philipp R. Heck.
||Vial with meteoritic nanodiamonds from the meteorite Allende. The dark shaded area at the bottom of the vial is the cluster of nanodiamonds. © The Field Museum, GEO86193_2c, Photographer: John Weinstein.|
We are also interested in the history of the delivery of extraterrestrial matter to Earth. Therefore, we analyze the chemical compositions of meteorites and micrometeorites that were preserved in terrestrial sediments. On the other end of the size spectrum of extraterrestrial material that fell to Earth are asteroids and comets. These usually form impact craters and can cause local to global catastrophes for life. We study such impact craters to find and analyze impactor material. Such studies will help geoscientists understand how the extraterrestrial material affected the environment and life on Earth during various times in Earth’s history.
Cut section of a fragment of the Canyon Diablo iron meteorite that produced the Meteor Crater in Northern Arizona some 50,000 years ago. FMNH Me144 #1. © The Field Museum, GEO86462d, Photographer: John Weinstein.
Modern Interstellar Dust
We have joined with scientists around the globe to find contemporary interstellar dust gathered by NASA's Stardust space mission launched more than a decade ago. We analyze the interstellar dust collector that was returned to Earth in 2006. To find craters made by modern interstellar dust we are studying thousands of high-resolution scanning electron microscope (SEM) images acquired with the Field Museum's SEM. Interstellar dust is important to study because it carries essentially all of the heavy elements in the Universe, among these are elements that are the essential building blocks of life. This project is part of an international collaboration and provides cosmochemists a first look at interstellar dust in the laboratory. The Field Museum’s Stardust team has already found several impact craters.
|The NASA spacecraft Stardust with the collector deployed. Artist's impression, credit: NASA/JPL.|
Chicago Center for Cosmochemistry
The Field Museum is part of the three-institution Chicago Center for Cosmochemistry (C^3) together with Argonne National Laboratory and the University of Chicago. C^3 is dedicated to promoting education and research in cosmochemistry. The center holds a weekly seminar during academic quarters. C^3 aims to take advantage of the strength of the cosmochemistry community in Chicago. The Field Museum's world-class meteorite collection, a superb array of cutting-edge analytical facilities and state-of-the-art sample preparation laboratories at Argonne and the U of C are core elements of C^3. It also serves as a magnet to attract cosmochemists from around the world to Chicago.