Welcome to an exciting journey into the world of meteorites! Today, we’re learning from Jim Holstein, a collection manager who specializes in meteorites, minerals, jewelry, and gemstones. Meteorites are the stars of the show, and we’re about to find out why they’re so fascinating.
Let’s start with the basics. A meteorite is a piece of rock from space that survives its fiery journey through Earth’s atmosphere and lands on the ground. But before it becomes a meteorite, it has two other names. When it’s floating in space, it’s called a meteoroid. As it streaks through the sky, it’s known as a meteor. Once it lands, it’s officially a meteorite.
Meteorites come in three main types: stony, iron, and stony-iron. Stony meteorites are made of rock, iron meteorites are made of metal, and stony-iron meteorites are a mix of both. These space rocks formed about 4.5 billion years ago at the beginning of our solar system.
Stony meteorites can be further divided into chondritic and achondritic types. Chondritic meteorites come from undifferentiated bodies, meaning they haven’t separated into layers like Earth’s core, mantle, and crust. Achondritic meteorites, on the other hand, come from differentiated bodies that have distinct layers.
Most meteorites originate from the asteroid belt between Mars and Jupiter. These asteroids sometimes collide, sending pieces on a new path that might cross Earth’s orbit. Every year, about 80,000 tons of space material enter our atmosphere, mostly as tiny dust particles. Occasionally, larger pieces, the size of cars, make it through, often landing in the ocean.
The majority of meteorites found on Earth are chondritic, making up nearly 90% of all meteorites. These are special because they contain metal mixed with minerals, giving them a shiny, sparkly appearance. The dark outer layer, known as the fusion crust, forms when the meteorite heats up as it enters our atmosphere.
Stony-iron meteorites are rare, comprising less than 1% of all meteorites. They contain beautiful crystals, like olivine, embedded in metal. These meteorites may have formed at the boundary between a planet’s core and mantle, where rock and metal mix.
Among the rarest meteorites are those from Mars. These pieces of the Red Planet are incredibly valuable for studying Mars’s mineralogy. When a large object hits Mars, it can send pieces of the planet into space, some of which eventually land on Earth. Scientists can identify Martian meteorites by matching their composition to the known characteristics of Mars’s atmosphere.
Meteorites are not just rocks from space; they are windows into the history of our solar system. From the common chondritic meteorites to the rare Martian pieces, each one has a story to tell. By studying them, scientists learn more about the formation and evolution of planets, including our own Earth.
Use clay or playdough to create models of the three main types of meteorites: stony, iron, and stony-iron. Pay attention to the textures and colors that represent each type. Once you’ve created your models, present them to the class and explain the characteristics of each meteorite type.
Imagine you are a meteoroid traveling through space. Write a short story or create a comic strip that describes your journey from the asteroid belt to becoming a meteorite on Earth. Include details about the changes you undergo as you become a meteor and finally a meteorite.
Research different meteorites and their features. Create flashcards with images and descriptions of various meteorites. Work in pairs to quiz each other on identifying the types of meteorites based on their characteristics and origins.
Create an informative poster about meteorites, highlighting their types, origins, and significance. Use images, diagrams, and interesting facts to make your poster engaging. Display your poster in the classroom to educate your peers about the fascinating world of meteorites.
Take a virtual tour of a museum or online exhibit that features meteorites. As you explore, take notes on the different meteorites you encounter. Share your findings with the class, focusing on any rare or unique meteorites you discovered during your virtual visit.
Here’s a sanitized version of the transcript:
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I think this is the only collections tour I’ve been on where I’ve been handed gloves. Hey! We’re here with Jim Holstein, who is the collection manager…
– Collection manager, right.
– Of meteorites, mineralogy, jewelry, and gemstones. But mainly meteorites because that’s our most popular exhibit.
– What is a meteorite?
– What do you think a meteorite is?
– A meteorite is a part of a planet that was blasted off, that came through space, through the atmosphere, and landed on Earth.
– Okay, that’s…
– Is that kind of close?
– That’s close enough. I mean, you could have my job— that’s all you need to know, actually. That’s it.
– That’s— oh, alright.
– But meteorites, yeah, these are the rocks that fall from space when they’re found on the surface of the Earth. We have three terms: a meteoroid is when it’s floating around in space; when it’s making that streak through the atmosphere, they call that a meteor; and then when you pick up the rock from the ground, they call that a meteorite.
– Nice. And then there are different kinds of meteorites.
– Right. There are three broad categories of meteorites. You have stony meteorites, which are made out of…?
– Stone.
– Iron meteorites which are made out of—
– Iron.
– Oh, you’re jumping ahead!
– And stony-iron meteorites which are made out of…?
– Both stone and iron!
– Yes!
– I am an expert!
– You are an expert.
And so when these things were originally formed at the beginning of our solar system about 4.5 billion years ago, you had two broad categories of stony meteorites: chondritic meteorites and achondritic meteorites.
– Okay, I don’t know what those are.
– Yeah. So now we’re getting a little bit deeper now. Chondritic meteorites are from planetary bodies that are undifferentiated.
– Now what does that mean?
– Yeah, I don’t know what that means.
– Let’s go to the board!
– Yay!
– Ok, so in the middle of the Earth, you have what is called the…?
– Core.
– Yes. Core.
– I didn’t know I was going to be quizzed today.
– You have to earn this. Outside the core you have the what?
– Uh, not the mantle…
– No, you’re right, it is the mantle.
– Is it? It is the mantle? Ok.
– And that’s my good spelling. And on the outside, the very thin layer, we call that—
– The crust!
– The crust. So core, mantle, crust. That’s a differentiated body. Some of these meteorites actually came from differentiated bodies out in the solar system. These are differentiated bodies that broke apart.
So for example, we talked about the three basic types— the iron, the stony, and the stony-iron meteorites. The iron meteorites are actually samples of the cores of these planetary bodies that are differentiated.
– So how do you get a core from a planet? I mean that’d have to be a pretty gigantic impact, or is it like spit up?
– Yeah, absolutely. No no, ok so back to the board again. What’s a good color for the sun?
– Red.
– I guess, I don’t have any yellow. So here we have the sun. S.
– That’s a tiny sun.
– And we’ll do the planets in blue. Then we have closest to the sun, we have an orbit, and a planet called Mercury, right?
– Mercury. And that is, what?
– Venus.
– Venus. And after that we have
– It’s Earth.
– Yeah, it is Earth. Yeah, clearly it’s Earth. And then beyond Earth, we have what?
– Mars.
– Mars, the red planet, Mars. And then out beyond Mars we have what? What’s the next one after Mars?
– Um, see I have to keep going through “my very enthusiastic mother”… Jupiter.
– Jupiter! Jupiter is out here. But there’s this gap here between Mars and Jupiter. And in this gap is the asteroid belt so we have asteroids, and these are all these failed planetary bodies that broke apart. And a lot of these were impacting each other. And these are all in orbit around the sun at this point.
So when they get impacted by another asteroid, it puts it on a different orbit which puts it in an elliptical around the sun, and sometimes, that elliptical orbit crosses the Earth’s orbit, so when the Earth is going around its own orbit, it would sometimes hit the orbit of one of these asteroids, or meteoroids and then you have a very frowny-faced Earth that gets hit by an asteroid. We have about 80,000 tons of material that enters the atmosphere every single year.
– Really?
– Most of it is dust size. And you have maybe one or two events, car-sized objects that hit the Earth, and most of it hits the ocean. Differentiated bodies: core, mantle, crust.
– Yeah.
– But that doesn’t comprise the majority of meteorites that we have. The majority of meteorites we have are these stony chondritic meteorites which come from undifferentiated bodies.
– So one all homogeneous lump?
– One all homogeneous thing. And these comprise about almost 90% of all meteorites that are found on Earth.
– Wow. Oh, well that’s pretty.
– And what’s special about those is that it didn’t differentiate, which means that it has all the metal still in the rock. It’s a very homogeneous piece of all metals, minerals, all mixed together. If you hold it in the right light…
– Yeah.
– You see little flakes of metal in there.
– It’s shiny.
– It’s very sparkly.
– Can you see it? Why is it dark on the outside?
– That’s called fusion crust, and that’s what happens when the thing enters the atmosphere. And as the atmosphere gets super heated, it melts the outside and that becomes black. You also get those indentations you see on the outside; those indentations are caused by atmospheric heating as well. And so these undifferentiated meteorites are the most common ones, and back in the early history of the solar system, these would eventually in some cases heat up, and become differentiated. Earth was an undifferentiated body at one time, and then it heated up to the point where all the metal went to the core and by mass it all sort of differentiated out, it separated itself out.
– Wow. That is amazing. My mind is being blown right now.
– So stony iron meteorites. These comprise less than 1% of all falls or finds.
– And this is the one that has both rock and iron in it?
– Mhm.
– It’s beautiful.
– You can see these nicely formed mineral grains. These are actually crystals, they’re actually gemstones that are embedded in this metal matrix.
– So what kind of gemstones are you–
– You usually see olivine, and it’s a very common gemstone on Earth. These are formed deep in the mantle, and a meteorite like that, one of the theories is that it was actually formed at the core-mantle boundary, so we had the illustration of the differentiated bodies—the core and mantle. The idea is that you get intermixing between the core and mantle, and when that body fell apart, that’s how they harden; they cool, they crystallize, and they freeze out with the minerals embedded in the metal.
Let’s talk about Mars!
– I want to talk about Mars. Ok, so we talk about the rarity of these things, and I talk about how the stony irons are the rarest of the three broad categories, but there are rarer objects still, and these Martian meteorites are in fact…
– Oh my gosh.
– One of the rarest types of meteorites.
– This is a piece of Mars.
– That is a piece of Mars. This fell in 2011 in Morocco.
– So what does this tell you about Mars?
– So basically when an object hits Mars, it actually excavates a part of Mars out of it and this actually came all the way from Mars so it tells a lot about the mineralogy. How do we know it’s from Mars? That’s the biggest question.
– Yeah.
– For example, the lunar meteorites that we have collected on Earth, we’re able to match those up geochemically to the lunar meteorites brought back by the Apollo astronauts.
– Ok.
– But we don’t have any Martian rocks.
– Because we haven’t been to Mars.
– We haven’t been to Mars.
– What is the Mars rover up to lately?
– It is looking at things very much similar to this right now. But, what we do know a lot about is the Martian atmosphere. We know what it’s made out of, and what this has inside of it is a sample of the Martian atmosphere. So that could be extracted and is an exact match to the Martian atmosphere.
– So it’s like a fingerprint, like atmosph—
– It’s a fingerprint. Atmospheres have fingerprints.
– That’s amazing!
– CSI Meteorites.
– That’s amazing!
– That’s what we do here.
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This version removes informal language and maintains a more professional tone while preserving the content’s essence.
Meteorite – A fragment of rock or metal from space that survives its passage through the Earth’s atmosphere and lands on the surface. – Example sentence: Scientists studied the meteorite to learn more about the early solar system.
Meteoroid – A small rock or particle from space that can become a meteor if it enters the Earth’s atmosphere. – Example sentence: The meteoroid traveled through space before it entered the Earth’s atmosphere and became a meteor.
Meteor – A streak of light in the sky produced by a meteoroid burning up as it enters the Earth’s atmosphere. – Example sentence: We watched the meteor shower and saw many bright meteors streak across the night sky.
Asteroid – A small rocky body orbiting the sun, mostly found in the asteroid belt between Mars and Jupiter. – Example sentence: The spacecraft was sent to study an asteroid to understand more about the building blocks of planets.
Chondritic – Relating to a type of stony meteorite that contains small mineral grains called chondrules. – Example sentence: The chondritic meteorite provided valuable information about the conditions in the early solar system.
Achondritic – Relating to a type of meteorite that does not contain chondrules and is similar to volcanic rocks found on Earth. – Example sentence: The achondritic meteorite was studied to compare its composition with that of Earth’s volcanic rocks.
Solar System – The collection of eight planets and their moons in orbit around the sun, along with smaller bodies like asteroids and comets. – Example sentence: Our solar system is just one of many in the galaxy, but it is the only one known to support life.
Mars – The fourth planet from the sun, known for its red color and the possibility of past water presence. – Example sentence: Scientists are exploring Mars to find evidence of past life and to understand its climate history.
Minerals – Natural, inorganic substances with a definite chemical composition and crystalline structure, found in rocks and meteorites. – Example sentence: The minerals found in the meteorite helped scientists determine its origin in the solar system.
Fusion Crust – A thin, glassy coating on the surface of a meteorite, formed by melting during its passage through the Earth’s atmosphere. – Example sentence: The fusion crust on the meteorite indicated that it had traveled through the atmosphere at high speed.
