Meteoritics and Polar Studies Research

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 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. 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.

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.

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.

Polar Studies

The Robert A. Pritzker Center for Meteoritics and Polar Studies has a strong interest in studies in the polar regions. The Tawani Foundation, that provided the generous funding to establish the Center sponsored several expeditions to Antarctica. Below are some impressions from past expeditions.

Members of the 2000 expedition in front of a Twin Otter aircraft at the Thiel Mountains, Antarctica.

Base camp at Patriot Hills, Antarctica.

Snow mobiles are essential when searching for meteorites. Thiel Mountains, Antarctica.

COL (IL) James N. Pritzker IL ARNG (Ret.) finding a stony meteorite in a ground blizzard at the Pecora Escarpment, Antarctica, January 2002.

A red flag marks the location and a geology hammer next to a stony meteorite found at the Moulton Escarpment in the Thiel Mountains, Antarctica in January 2000.