Published: March 3, 2017

Fascinating Meteorites With Clues To Understanding Our Solar System

Philipp Heck, Robert A. Pritzker Associate Curator for Meteoritics and Polar Studies and Head, Robert A. Pritzker Center, 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

A flat stone slab that's reddish in color, with a green object in the center, surrounded by a tan-colored ring

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. 

A man wearing work clothes and rain boots standing on a muddy, rocky shelf

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

2. Rare green meteorites

An irregularly shaped stone with a rough outer surface and a shiny spot that is green and orange

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

A large irregularly shaped stone that's mostly smooth and gray, with ripples

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

A large black and orange stone with many depressed areas

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

Philipp R. Heck is the Robert A. Pritzker Associate Curator of Meteoritics and Polar Studies at the Field Museum of Natural History in Chicago, IL. He is also an Associate Professor (part time) at the University of Chicago's Department of the Geophysical Sciences and the College, and a member of the Chicago Center for Cosmochemistry.

As the curator in charge and head of the Robert A. Pritzker Center for Meteoritics and Polar Studies, Philipp R. Heck oversees the collection of meteorites, the largest meteorite collection housed at a private research institution. Other responsibilities include the curation of the gem, mineral, rock and economic geology collections.

Visit the website of the Robert A. Pritzker Center for Meteoritics and Polar Studies for more information.