Join us as we delve into the fascinating world of meteoritics with Philipp Heck, the Robert A. Pritzker Associate Curator for Meteoritics and Polar Studies. Our journey begins with understanding the age of the solar system, marked by the discovery of ancient minerals that provide a glimpse into the universe’s past.
The solar system’s age is defined by large, white, aluminum-rich inclusions found in certain meteorites. These inclusions are the oldest minerals formed in our solar system, dating back to 4.567 billion years ago, a point we refer to as T-0 or time zero. This specific specimen allows us to pinpoint the beginning of our solar system. When I present this to the public, I often offer a slice encased in plastic, inviting people to hold the oldest material known to humanity.
Interestingly, some grains within these meteorites are even older than the sun itself, potentially dating back 5.5 billion years. These pre-solar grains can be analyzed chemically, revealing isotopic compositions that are highly anomalous compared to anything else in the solar system. Their presence in the rock indicates they were part of the original mixture from which the rock formed, making them older than 4.6 billion years.
Through the study of these minerals, we learn that the solar system likely formed from a cloud of gas and dust, originating from various stellar sources, including supernovae. These stellar explosions created new elements, which later cooled and condensed into gas. Stars similar to the sun, at the end of their life cycle, expanded into red giants and expelled matter into space. From this stellar ejecta, the pre-solar cloud emerged.
Within this pre-solar molecular cloud, a rotating disk of gas and dust known as the protosolar disk formed. This disk eventually gave rise to the protosun and later the sun itself, along with the building blocks of planets. While most of this matter was altered and heated, erasing the pre-solar signature, a small fraction of pre-solar material survived unaltered.
Among the most abundant pre-solar materials are nano-diamonds, tiny structures only 2 nanometers across, composed of about 1,000 to 2,000 carbon atoms. These diamonds can be extracted from meteorites by dissolving other materials, leaving behind a residue of diamonds. Despite their minuscule size, they represent a literal form of stardust.
Discovered in 1987 at the University of Chicago, these nano-diamonds offer a unique glimpse into the past. For those of us studying earth sciences, like myself during my undergraduate years in Switzerland, the discovery of such ancient materials is incredibly captivating. It opens up a world of questions and possibilities for further research.
These nano-diamonds, composed of pure carbon, have survived the formation and evolution of our solar system, unlike most other materials. The carbon in these diamonds shares a common origin with the carbon that makes up all life on Earth, highlighting a profound connection between the cosmos and life as we know it.
Studying these ancient diamonds allows us to explore the history of the universe and understand the origins of our solar system. While they may not be suitable for engagement rings due to their size, their value lies in the stories they tell about the cosmos and our place within it.
Engage in a hands-on workshop where you will analyze meteorite samples to identify aluminum-rich inclusions. Use microscopes and spectrometry tools to determine the age of these inclusions, simulating the methods used by scientists to date the solar system.
Participate in a simulation exercise where you will model the formation of pre-solar grains. Use isotopic data to trace the origins of these grains and discuss their significance in understanding the solar system’s formation.
Work in groups to create a physical model of the protosolar disk using various materials. Present your model to the class, explaining the processes that lead to the formation of the sun and planets from the disk.
Conduct an experiment to extract nano-diamonds from a simulated meteorite sample. Learn about the chemical processes involved and discuss the significance of these diamonds in understanding cosmic history.
Engage in a debate on the implications of the shared origin of carbon in nano-diamonds and life on Earth. Discuss the philosophical and scientific perspectives on our connection to the cosmos.
Here’s a sanitized version of the transcript:
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I’m here with Philipp Heck, who is the Robert A. Pritzker Associate Curator for Meteoritics and Polar Studies.
Today we’re going to talk about the age of the solar system. These large, white, aluminum ridge inclusions that you can see here are the oldest minerals that formed in the solar system, and they can be dated. This marks the start of the solar system, which we refer to as T-0, or time 0. It’s 4.567 billion years—an easy number to remember.
We know how old the solar system is because of this specific specimen. This defines T-0. When I give public talks, I usually provide people with a slice in plastic and say, “You can hold the oldest piece of material in the solar system.” Even though you can’t see it, the oldest material available to anyone on this planet is in there. There’s nothing older that you can touch.
Wow. Pre-solar grains are older than the sun and older than the meteorite itself. Some of them might be as old as 5.5 billion years.
And how do you know that?
These pre-solar grains can be analyzed chemically. Their isotopic composition is highly anomalous, very different from anything in the solar system. Their composition cannot be explained by any process that occurs in the solar system. The fact that they are embedded in that rock tells us they could not have been incorporated later; they must have been part of the mixture from which the rock formed. Since the rock formed 4.6 billion years ago, they must be older.
Older than 4.6 billion years.
Some minerals can even be dated. So far, we have only dated approximately 30 grains. Most of them are about 200 million years older than the sun, and a few are about a billion years older than the sun, making them about 5.6 billion years old. We think the solar system formed from a cloud of gas and dust, which originated from different sources, including stellar explosions like supernovae. During these explosions, new elements formed. After the matter cooled down, some of it condensed as gas. Other stars, similar to the sun but at the end of their life, expanded, became red giants, and expelled matter into space. From this mixture of stellar ejecta, the pre-solar cloud formed.
Within this pre-solar molecular cloud, the protosolar disk formed—a rotating disk of gas and dust. The protosun formed, and later, the sun. Planetary building blocks formed. Most of the matter was altered and heated, so the pre-solar signature is not visible anymore, but some of this pre-solar matter survived without alteration. That’s what’s trapped in here—only a tiny fraction. The most abundant type of pre-solar materials are diamonds—nano-diamonds. These diamonds are tiny, only 2 nanometers across, consisting of about 1,000 to 2,000 carbon atoms. We can extract them from meteorites by dissolving everything else, leaving us with the acid residue of diamonds. In this little vial, I have billions of diamonds. You normally wouldn’t see them because they are so small they don’t scatter light, but they clump together, forming a white residue.
These are all diamonds. It’s literally stardust.
It’s ethereal looking, kind of floating around in this nebulousness. These diamonds were discovered in Chicago in 1987 at the University of Chicago, with a Field Museum meteorite.
Really? That’s overwhelming. How did you get into this?
When I first heard about this, I was extremely fascinated. I learned about it while studying earth science in Switzerland and did an undergraduate project in a cosmochemistry lab there. I thought, “This is so fascinating; would it be possible to do a PhD there?” I was completely hooked. I had always been interested in astronomy and volunteered at the local observatory, thinking, “If I could do that for a living, that would be fantastic.” The opportunity came up, and I was able to work on stardust for my PhD.
Really?
Yes, I feel very fortunate to work on such ancient material. It keeps us motivated, and it’s really great. With every question that you answer, you open up ten more questions that can be studied. You have to make wise decisions about which questions are worth pursuing.
Exactly. One of these is the origin of those nano-diamonds. Nano-diamonds are basically pure carbon, and they survived the formation and evolution of our solar system—almost nothing else did. Almost everything has been altered. The carbon in our bodies and skin doesn’t show a pre-solar signature anymore, although it might have the same origin as these diamonds.
So, the carbon that makes up those diamonds is the same carbon that makes up all life on Earth.
Exactly. This is like our great ancestor, essentially.
Yes, we have a common origin. These diamonds and life on Earth represent a tiny fraction that survived all these billions of years since the planets and Earth formed. By studying those diamonds, we can learn about the past—about the time before the solar system.
If you were to take those diamonds to a pawn shop, how much would one be worth?
They probably wouldn’t know. I always say they probably wouldn’t make nice engagement rings because they are so small, but there are millions!
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This version removes informal language and clarifies the content while maintaining the essence of the discussion.
Meteoritics – The science that deals with meteors, meteorites, and meteoroids, including their origins and impacts on Earth. – The study of meteoritics has provided valuable insights into the early solar system’s conditions.
Minerals – Naturally occurring inorganic substances with a definite chemical composition and crystalline structure, often found in rocks. – Geologists analyze minerals in meteorites to understand the composition of celestial bodies.
Solar – Relating to or determined by the sun. – Solar radiation plays a crucial role in Earth’s climate system and energy balance.
System – A set of interacting or interdependent components forming an integrated whole, often used to describe celestial bodies and their interactions. – The solar system consists of the sun, planets, moons, and other celestial objects bound by gravitational forces.
Grains – Small particles or crystals, often referring to the tiny solid particles found in space or within meteorites. – The analysis of presolar grains in meteorites helps scientists trace the history of stellar processes.
Formation – The process by which a particular structure or substance is created, often used in the context of celestial bodies. – The formation of planets is a complex process that involves the accumulation of dust and gas in a protoplanetary disk.
Dust – Fine particles of matter, often found in space, that can contribute to the formation of stars and planets. – Interstellar dust plays a significant role in the cooling and collapse of molecular clouds, leading to star formation.
Diamonds – Crystalline forms of carbon that can be found in meteorites, providing clues about high-pressure conditions in space. – Nanodiamonds found in some meteorites suggest that they formed in the intense environments of supernovae.
Carbon – A chemical element that is the fundamental building block of life and is found in various forms throughout the universe. – Carbon compounds in meteorites are studied to understand the potential for life elsewhere in the universe.
Life – The condition that distinguishes living organisms from inorganic matter, often explored in the context of astrobiology. – The search for extraterrestrial life focuses on identifying planets with conditions suitable for sustaining life as we know it.
