Published: March 3, 2017

Fascinating Meteorites With Clues To Understanding Our Solar System

Philipp Heck, Sr. Director, Negaunee Integrative Research Center; Robert A. Pritzker Curator for Meteoritics and Polar Studies; Head, Robert A. Pritzker Center, Negaunee Integrative Research Center

Meteorites have been falling to Earth for literally hundreds of millions of years—and continue to land here today. Our Meteorites exhibition features rare and fascinating meteorites, from fossil meteorites to a meteorite on Mars. 

Meteorites have been falling to Earth for literally hundreds of millions of years—and continue to land here today. Most meteorites come from the asteroid belt, a ring of rocky debris orbiting the Sun between Jupiter and Mars. This belt formed 4.6 billion years ago. So, by studying meteorites, we can continue learning about the very origins of our solar system. Here are four kinds of meteorites you can see for yourself at the Museum:

1. The only fossil meteorites in the Americas

Fossil meteorites are so rare that only 101 have been discovered to date (and four of them are here at The Field Museum!). But what is a fossil meteorite? The fossilization process for meteorites happens in the same way that organisms—plants and animals—become fossilized. The meteorite’s original materials are gradually (very, very gradually) replaced by minerals in the ground surrounding it.

All of the fossil meteorites that have been discovered so far come from the same spot: deep in a limestone quarry in Sweden that used to be an ancient sea. Based on the age of the rock around them, we know that the now-fossilized meteorites fell to Earth about 466 million years ago. They’re debris from a major collision event that happened in the asteroid belt when they broke off of what’s called the parent body. These meteorites were some of the first pieces to arrive on Earth after the collision. 

See how the fossil meteorite test works on The Brain Scoop.

2. Rare green meteorites

These are ungrouped meteorites that came from asteroids we didn’t even know existed until a few years ago. “Ungrouped” means that these meteorites don’t fit the classification of any previously documented meteorites—in other words, that they’re from small planets that scientists haven’t sampled before. That’s what makes an ungrouped meteorite an exciting find: it’s a window into a part of our solar system that remains to be explored. The hope is that one day, we’ll have enough samples of this new type that we’ll be able to identify a new group of meteorites. In addition, the two meteorites that we have appear green, which is very unusual. Most meteorites have a thin black outer fusion crust, and inside, they are either light or dark gray, or black. 

3. The Chelyabinsk meteor

You probably remember hearing the news reports about this one: a brilliant, blinding explosion that took place over the Russian district of Chelyabinsk in 2013. In fact, the fireball burned brighter than the sun. It was caused by the explosion of an enormous meteor as it entered Earth’s atmosphere at an extremely high speed.

The meteor was estimated to weigh about 11,000 metric tons (or about 24,250,000 pounds, nearly as heavy as the Eiffel Tower) before it exploded. The shockwave caused injuries to more than 1,500 people—a very rare occurrence of a meteorite fall directly impacting people’s lives. The Chelyabinsk meteor was probably a once-in-100-years event, but it made us realize how vulnerable we humans really are to meteorite impacts. 

4. A Mars meteorite

Just as meteorites fall to Earth, they also land on other planets. Thanks to 3D photographs taken by NASA’s Mars Exploration Rover Opportunity, we’re able to get a close-up, detailed look at an iron meteorite spotted on Mars. A life-size replica of this Mars meteorite was created using imagery and data gathered by the Opportunity. Found in 2009, the real meteorite is still on Mars.

See these meteorites and more on display in the exhibition Meteorites.

Several of the specimens on display were loaned or donated by private collector Terry Boudreaux. For over a decade, Terry Boudreaux has continuously provided The Field with loans and donations of precious and fresh meteorites for research and exhibit. The fossil meteorite specimens were loaned by private collector Mario Tassinari from Sweden.


Philipp Heck
Sr. Director, Negaunee Integrative Research Center; Robert A. Pritzker Curator for Meteoritics and Polar Studies; Head, Robert A. Pritzker Center

Philipp R. Heck serves as the Senior Director of Research at the Field Museum. Research at the Field Museum is conducted in the areas of Earth and Planetary Sciences, Life Sciences, Anthropology and Archeology, and is united in the Negaunee Integrative Research Center. Heck is the Robert A. Pritzker Curator of Meteoritics and Polar Studies at the Field Museum of Natural History in Chicago, IL in the Science & Education department and a Professor (part time) at the University of Chicago's Department of the Geophysical Sciences and the College (https://geosci.uchicago.edu/people/philipp-heck/). 

Heck's research focuses on presolar grains to understand our parent stars and the history of our Galaxy, early solar system materials, asteroids, and on the delivery history of extraterrestrial matter to Earth. For his research he studies the mineralogy and geochemistry of meteorites, micrometeorites and space-mission returned samples and also of fossil meteorites and micrometeorites found in Earth's sedimentary record. Heck joined the sample analysis team of NASA's OSIRIS-REx sample return mission. Heck was a member of the international research consortium to find and study the first modern interstellar dust returned by NASA's Stardust Mission. Heck is an executive committee member of the Extraterrestrial Materials Analysis Group (ExMAG) and is chairing the Microparticle Subcommittee.

As the curator in charge, Philipp R. Heck oversees the collection of meteorites at the recently established Robert A. Pritzker Center for Meteoritics and Polar Studies, the largest meteorite collection housed at a private institution with more than 12000 specimens and more than 1600 different meteorites. Other responsibilities include the curation of the gem, mineral, rock and economic geology collections.


Philipp R. Heck came to the Field Museum in March 2010 from the University of Chicago, where he was a postdoctoral scholar working on new analytical techniques for presolar grains. He obtained his M.Sc. and Ph.D. degrees at ETH Zurich in Switzerland in geo- and cosmochemistry. He then worked as a postdoctoral fellow at the Max-Planck-Institute for Chemistry where he studied the first comet dust brought back from Comet Wild-2 by NASA’s Stardust Mission and at the University of Wisconsin-Madison where he worked mainly on fossil meteorites and banded iron formations from around the world. For his studies he uses specialized analytical techniques such as secondary ion mass spectrometry (NanoSIMS, IMS-1280 and TOF-SIMS), noble gas mass spectrometry, atom probe tomography, scanning electron microscopy and electron microprobe analysis. Sample preparation for atom-probe work is performed with focused ion beam workstations.