Research
Research Highlights
We performed age dating of presolar stardust – the oldest solids on Earth. Found in meteorites, asteroids and comets, these ancient grains are solid samples of stars that formed before our Solar System.
We helped refine the Moon's age: showing it is at least 40 million years older than previously known.
We found a record of the young Sun's intense activity in blue hibonite, one of the earliest minerals to form in the Solar System.
We uncovered a record of pebble ejection and redeposition in a meteorite, revealing the same process first observed on asteroid Bennu by NASA's OSIRIS-REx mission.
Our group discovered that meteorite types rare today were once abundant, demonstrating that the flux of meteorites to Earth is biased at any given time.
In collaboration with Northwestern University, our group pioneered applying atom-probe tomography to extraterrestrial samples, advancing nanoscale analysis in planetary science.
We are part of the organics sample analysis team of NASA's OSIRIS-REx mission. The pristine samples from asteroid Bennu offer unprecedented insight into the Solar System's starting materials.
Research Themes
Early solar System
We are interested in the earliest solar system processes that are recorded in components of meteorites. Minerals from refractory inclusions, like hibonite and spinel are among the first to have condensed in the cooling solar nebula. By studying their structure, chemical and isotopic composition we can gain a better understanding of the early solar system. Some of the key processes happened within the first 100,000 to millions of years in solar system evolution that defined the fate of the solar system.
Presolar Grains
Presolar grains are minerals that are older than anything else in our Solar System (Podcast). 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 study the elemental and isotopic compositions of presolar grains 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 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.
The delivery of extraterrestrial matter to Earth
We are also interested in the history of the delivery of extraterrestrial matter to Earth. We study the origins and delivery modes of meteorites and micrometeorites that are preserved in terrestrial archives such as sedimentary rocks. Such studies will help to better understand the collisional evolution of the solar system. Results from these studies also have the potential to investigate if accrection of extraterrestrial material affected the environment on Earth at different geological times.
See our recent highlight:
Meteorites
Through the study of meteorites we can learn more about their origins, their parent planets, and the formation of the solar system.
We recently reported the first evidence of Bennu-like pebble-ejection and redeposition recorded in a meteorite (Aguas Zarcas).
Our team led the international consortium to study the Hamburg meteorite.
We are currently working on several ordinary chondrites and martian meteorites.
Please check out our basic introduction to meteorites and their study (meteorite basics, studying meteorites).
Micrometeorites
Micrometeorites (MMs) are more abundant than meteorites as they represent the largest mass of extraterrestrial material arriving on Earth. By studying fossil MMs we have shown that their sources change through time. Antarctic MMs also serve as reference samples for fossil micrometeorites that are found in Earth's sedimentary record. We currently collaborate with a Belgian group of micrometeorite researchers to collect and study micrometeorites from Antarctica.
Read more about our most recent field expedition.
Atom-Probe Tomography in Cosmochemistry
We have pioneered the application of atom-probe tomography (APT) in collaboration with colleagues from the Northwestern University Center for Atom Probe Tomography (NUCAPT). APT is particularly useful for studying samples that are too small for conventional techniques like NanoSIMS and where chemical and in some cases isotopic compositions in 3D needs to be analyzed. So far, we have successfully analyzed meteoritic nanodiamonds, silicon carbide, olivine, ilmenite, kamacite and taenite, and zircons. With the latter we were able to improve the chronology of the evolution of the Moon.
Space Weathering
Surfaces of airless bodies like the Moon and asteroids are constantly bombarded by cosmic rays, energetic particles from the sun and other stars, and by micrometeorites. This bombardment changes the composition and appearance of the surface, and effect that is called space weathering. Space weathered surfaces can be observed with telescopes over hundreds of millions of miles from Earth but actually operate at the nanoscale. We are conducting research on the nanoscale with atom probe tomography to better characterize space weathering on the Moon and on asteroids.
Laboratories
Our group has the following tools and infrastructure available at the Field Museum: sample preparation laboratory incl. fine sectioning and polishing equipment, including a wire saw, cosmochemistry laboratory with centrifuge, laminar flow benches, fumehoods and a cleanroom, a variety of optical microscopes, WITec 300 R Raman spectroscopy system, Hitachi SU-7000 field-emission scanning electron microscope with Oxford Instruments XMax 50 SSD-EDS detector, two NSI XCT scanners (X15 and X5000), Thermo Scientific iCAP LA-ICP-MS, XRF. Through collaboration we also have access to the Cameca LEAP 5000 Atom Probe at nearby Northwestern University, a Tescan Lyra FIB-SEM with EDS/WDS/EBSD at nearby University of Chicago. Our cosmochemists have also access to Northwestern's NUANCE instrument park. We are also performing important analyses for our projects at the noble gas spectrometry lab at ETH Zurich and the IMS-1280 at WiscSIMS through longstanding collaborations.
Polar Studies
Through the Robert A. Pritzker Center for Meteoritics and Polar Studies we also support research projects in the polar regions in other scientific disciplines. See information on expeditions to Antarctica to Queen Maud Land, including Lake Untersee, to Livingston Island and other islands near Antarctica, and to Norway.