Imagine holding a rock that’s four and a half billion years old! That’s half a billion years older than any rock on Earth. If you want to understand how our planet and solar system came to be, these ancient space rocks are the key.
I’m Tim McCoy, a meteorite curator at the Smithsonian’s National Museum of Natural History. I study rocks that have fallen from the sky, like the one I’m holding. This rock is a piece of an asteroid that landed on Earth. It’s incredible because it contains clues about the early solar system, how Earth got its first ingredients for life, and even where we might find resources for future space travel.
These tiny pieces of an ancient asteroid were collected and brought back to Earth by NASA. They are part of one of NASA’s most ambitious missions. These rocks help us unlock the secrets of our solar system’s past.
Space rocks like these are made of cosmic sediment. Each particle was once floating in the cloud of gas and dust where our solar system formed. On Earth, sedimentary rocks form over time through erosion and compression. In space, gravity pulls together tiny rocks, dust, and gas to form asteroids.
Asteroids and rocky planets, including Earth, formed around the same time, about four and a half billion years ago. However, Earth’s oldest rocks aren’t as old as the planet itself. Earth’s surface is constantly changing due to wind, rain, and tectonic activity, which erases its earliest rocks. In contrast, asteroids don’t have weather or tectonic activity, so they remain unchanged, preserving a snapshot of the early solar system.
When space rocks land on Earth, they get contaminated by Earth’s environment. To study them accurately, scientists need rocks that haven’t been touched by Earth’s air, dirt, or water. NASA achieved this by sending a spacecraft to an asteroid to collect pristine samples.
In 2016, NASA launched the Osiris-Rex mission to an asteroid called Bennu. Bennu orbits between Earth and Mars and has a slim chance of hitting Earth in the distant future. The mission aimed to understand the origins of these rocks and the solar system.
After two years, Osiris-Rex reached Bennu and spent two more years mapping its surface. Landing on Bennu was like landing in a ball pit because of its loose surface. The spacecraft collected samples using a clever device and returned to Earth in 2023.
The samples from Bennu might look like dark rubble, but they hold valuable information. Scientists use special machines to analyze these rocks, revealing their chemical makeup. They’ve already discovered water in the minerals, supporting the idea that asteroids brought water to Earth.
These rocks also contain carbon and organic molecules, which could provide clues about how life began. Elements like carbon, nitrogen, phosphorus, and sulfur, found in these rocks, are essential for life.
Scientists are excited about the surprises in the Bennu samples, including minerals not seen in other space rocks. These discoveries will help us understand the formation of our solar system and the potential for life on other planets.
Studying these samples is like time travel, giving us a glimpse into the past. As scientists continue their research, they leave us with a fascinating question: Could a planet like ours exist in another solar system?
Fun fact: The asteroid Bennu was named by a kid! If you could name an asteroid, what would you call it?
Imagine you are a scientist studying space rocks. Use clay or playdough to create your own model of an asteroid. Think about the textures and colors you might find on a real space rock. Once your model is complete, present it to the class and explain what makes your asteroid unique and what secrets it might hold about the early solar system.
Work in groups to create a timeline of the solar system’s formation, focusing on the role of asteroids and space rocks. Include key events such as the formation of the solar system, the creation of asteroids, and the Osiris-Rex mission to Bennu. Use drawings, images, and brief descriptions to make your timeline informative and visually appealing.
Just like the asteroid Bennu was named by a kid, you have the chance to name your own asteroid. Think of a creative and meaningful name, and write a short paragraph explaining your choice. Share your name and explanation with the class, and vote on the most interesting asteroid name.
Conduct a mock investigation of a space rock sample. Use a magnifying glass to examine a rock or mineral sample provided by your teacher. Record your observations about its color, texture, and any other interesting features. Discuss with your classmates what these features might tell us about the rock’s history and origin.
Participate in a class debate about the importance of space missions like Osiris-Rex. Divide into two groups: one supporting the continuation of such missions and the other questioning their necessity. Research your arguments and present them to the class, considering the scientific, economic, and ethical implications of space exploration.
Here’s a sanitized version of the YouTube transcript:
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So when you hold this, this rock is four and a half billion years old. It’s a half a billion years older than any rock on Earth. If you really want to understand the origin of our planet and our solar system, you go to rocks like these.
Here I’m holding a chunk of an asteroid that fell to Earth. It’s amazing to hold in your hands. Space rocks are fascinating, but these tiny specks of dust might be the coolest space rocks of all because they hold answers to some huge questions: how our solar system formed, how Earth got the first ingredients for life, and maybe even where to find the resources that will one day let humans travel beyond Earth.
These are tiny pieces of an ancient asteroid collected and brought back to Earth in one of NASA’s most ambitious missions. I was invited to be one of the first people to see those rocks up close. Today, we’re going to learn how these specks of space rock will help unlock our solar system’s most ancient secrets.
My name’s Tim McCoy. I’m a curator of meteorites here at the Smithsonian’s National Museum of Natural History. Most of the time, I study rocks that have fallen from the sky like the one I’m holding.
The amazing thing about this rock is what it’s made of. This is a sedimentary rock, but it’s cosmic sediment. Each of these little particles was a free-floating thing in the cloud of gas and dust where our solar system formed. On Earth, sedimentary rocks form after eons of erosion, piling up little grains of dirt and sand and squishing them together. But a space rock like this is formed by tiny rocks and dust and gas getting pulled together by gravity.
These little white things are the solar system’s dust bunnies. They were blobs of dust floating around in the early solar system before anything else formed. Just like the dust bunnies in your house, this is the dust of the solar system. It’s wild to me that gravity can do enough work to bring this stuff together.
Four and a half billion years is a long time. This is the process that has formed every object in our solar system: planets, moons, and asteroids. Some of those bodies are solid, but some are more like piles of rubble. These tiny bits are barely pulled together by gravity, yet they’re still able to create asteroids up to hundreds of kilometers across.
If you go to a certain kind of asteroid, you’re going to find a rock just like this sitting on its surface. Asteroids and rocky planets, including Earth, all formed at about the same time, around four and a half billion years ago. But Earth doesn’t actually have any rocks that old; the oldest rocks on Earth aren’t from Earth. They’re from space.
Let me explain: here on Earth, wind, rain, and chemical reactions wear down and change old rocks. Meanwhile, large portions of Earth’s crust get recycled through plate tectonics and volcanoes. Over time, these processes have wiped away Earth’s earliest rocks. Those traces of our planet’s earliest history are just gone.
Our oldest rocks are nowhere near as old as our planet, but asteroids don’t have plate tectonics or weather cycles. They can’t hold onto an atmosphere, so they don’t have things like wind wearing them down. Unlike planets, asteroids basically haven’t changed in all those years since they formed. For the most part, they’re just cold rocks sailing through space, snapshots of the solar system as it was billions of years ago.
That chunk of rock I’m holding came from an asteroid. It formed in the early solar system, broke off, blazed through our atmosphere, and crashed onto our planet. Scientists like Tim are interested in rocks like these because they’re full of secrets about an era before Earth even existed. They let us explore the chemistry of the early solar system and how it evolved.
But there’s one big problem: space rocks that land on Earth are contaminated by Earth. To get the best, most accurate picture of the early solar system, we need to get some very old rocks that have never touched Earth’s air, dirt, or water. NASA just did that. They sent a spacecraft to an asteroid to pick up some rocks and bring them back to Earth. They’ll be studied, completely sealed off from earthly contamination—a pristine time capsule of the early solar system.
What will we find in that time capsule? Maybe clues about how life started. The ingredients for life must have been around before life arose, but where did they come from?
In many of these rocks, you find carbon and nitrogen, and in some, you find hydrogen and oxygen—water—as well as phosphorus and sulfur. These are the things that make up all living things on this planet. Everything that has ever lived or does now live on this planet comes from rocks like these—the ingredients for life.
These ingredients aren’t especially complex, chemically speaking—amino acids or the building blocks of DNA. They could have formed out of simpler chemicals that were already in the solar system before life arose. Scientists like Tim have actually found some of these chemical building blocks in meteorites.
But here’s where the problem about Earth contamination comes in. When studying a rock that fell to Earth, scientists can never be a hundred percent sure that the chemicals they find didn’t come from Earth.
In the case of some of these rocks, we know they have organic molecules that were present before life here on the planet, but every time one falls on Earth, it’s contaminated by life. Life is everywhere on this planet.
Scientists have been worried about space contamination since the moon missions. When Apollo astronauts returned to Earth after visiting the moon, they spent 21 days in an airtight quarantine chamber just in case they brought back some unknown lunar life to infect the planet. But what Tim and other scientists are concerned about is life from Earth contaminating the space rocks they want to study.
So they had an idea: let’s go get one, bring it back in a way that it’s not contaminated, and really understand water and organics and the things that are out there in space. As soon as a meteorite falls on Earth, it’s contaminated. So let’s get it pristine.
Hopping over to an asteroid to scoop up some rocks and shoot them billions of miles back to Earth is no small task. People have only pulled it off twice before, in 2010 and 2020, when Japanese probes brought back tiny samples from two asteroids. But NASA wanted to go to an even older asteroid and bring back even more material. They chose one called Bennu.
Bennu is a near-Earth asteroid that mostly orbits between Earth and Mars, but it crosses over Earth’s orbit when it comes closest to the sun. Bennu has a slim chance of hitting Earth in the 22nd or 23rd century, but for now, it’s nothing to worry about—it’s still tens of millions of miles away.
In 2016, NASA launched a probe to this rock, a mission called Osiris-Rex. The mission aims to understand how these rocks came to be, how the asteroid came to be, and how the solar system came to be.
It took two years just to get to Bennu, but in 2018, Osiris-Rex finally entered orbit around it. But how do you land on a big pile of rubble that’s less than a kilometer across, barely held together by gravity? NASA came up with a clever idea. They spent two years circling the rock, mapping its surface, and looking for the safest spot to land.
Finally, they picked their target. They maneuvered the spacecraft lower and lower, adjusting its speed to match the rotation of the asteroid. Then, when they were right over the surface, they made contact.
Landing on Bennu wasn’t like landing on Earth or the moon. NASA described it more like landing in a ball pit. The loose ground just gave way under the probe. Osiris-Rex spent a grand total of five seconds on the surface of Bennu, but it made the most of it.
They used a clever device that released gas to fluidize the loose particles, which they called regolith. They caught them in a container, brought it up, closed it all up, and then took off. After several months, they decided they were ready to leave the asteroid and spent three years getting back to Earth.
In late 2023, seven years after it launched, that capsule carrying a few hundred grams of asteroid material reentered Earth’s atmosphere, came in over the west coast of the United States, and a few hours later, it landed in Utah. A day after that, it went to Houston, and now we have samples to study.
Just looking at it, the sample might not seem very special—just some dark rubble. But geologists have a special machine for looking at samples like these, and it shows us things that our eyes could never see.
This machine generates a beam of electrons that hit a sample, generating X-rays. The devices on each side measure the energy of those X-rays and tell us what elements are in there. This gives us a chemical fingerprint of the elements present.
For example, if we take a hexagon-shaped grain and analyze it, we can see iron and sulfur, indicating that this is a sulfide mineral deposited by water four and a half billion years ago when this asteroid was essentially wet mud on its surface.
This is the kind of analysis scientists are doing on the Bennu sample. They’ve already made some exciting discoveries, like finding water tied up in the minerals, which supports the theory that Earth’s oceans were filled with water by countless asteroids slamming into the young planet.
In the future, water from asteroids could also be crucial for space travel. Water is a valuable resource in space, and mining it could save significant costs associated with launching water from Earth.
These rocks are also rich in carbon and organic molecules, which could hold clues about the molecules that eventually led to the emergence of life on Earth. Throughout this rock, there are elements like carbon, nitrogen, phosphorus, and sulfur—all the elements that make up living things.
There have also been surprises in the dark debris, including light flecks made of minerals that scientists haven’t found in other space rocks. So far, it’s a mystery what those are doing there.
Geologists have plenty to work with, and they’ll be making discoveries from the Bennu samples for a long time. These tiny pieces of rock are yielding enormous knowledge about where we come from and how our solar system formed.
Scientists will be studying these samples for generations. This is like real-time travel in a way. Scientists have this piece of our solar system frozen in time, locked in those grains of dust and rock, holding answers about how our planet and others came to be.
Every great scientific story ends with another question. This leaves us with an amazing one: could a planet like ours exist in another solar system made of the same elements and molecules? I hope we find the answer.
Thank you for watching this video and for sticking around to the end. Here’s a fun fact: NASA asked people for ideas about what to name that asteroid, and Bennu was picked by a kid. I think that’s really fun! If you got the chance, what would you name an asteroid? Leave a comment down below and let me know.
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Imagine you’re a farmer out plowing your field and you find something like this—you might break your plow!
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This version removes any inappropriate language and maintains the informative content of the original transcript.
Space – The vast, seemingly infinite expanse that exists beyond Earth’s atmosphere where all celestial bodies are located. – Example sentence: Astronomers use telescopes to explore the mysteries of space and discover new planets and stars.
Rocks – Solid mineral material forming part of the surface of the Earth and other similar planets, often composed of minerals. – Example sentence: Geologists study different types of rocks to understand the history and structure of the Earth.
Asteroid – A small rocky body orbiting the sun, mostly found in the asteroid belt between Mars and Jupiter. – Example sentence: Scientists track the paths of asteroids to ensure they do not collide with Earth.
Earth – The third planet from the sun in our solar system, home to diverse life forms and ecosystems. – Example sentence: Earth is unique in our solar system because it has liquid water and supports life.
Solar – Relating to or determined by the sun. – Example sentence: Solar energy is harnessed from the sun’s rays and can be used to power homes and devices.
System – A group of interacting or interrelated entities that form a unified whole, such as the solar system. – Example sentence: The solar system consists of the sun, eight planets, and various other celestial bodies.
Samples – Small parts or quantities intended to show what the whole is like, often used in scientific studies. – Example sentence: Scientists collect rock samples from the moon to study its composition and history.
Minerals – Naturally occurring substances, usually solid and inorganic, with a definite chemical composition and crystalline structure. – Example sentence: Minerals like quartz and feldspar are common components of many types of rocks.
Carbon – A chemical element that is essential to all known life forms and is a major component of organic compounds. – Example sentence: Carbon is found in all living organisms and is a key element in the carbon cycle on Earth.
Water – A transparent, tasteless, odorless, and nearly colorless chemical substance that is essential for all forms of life. – Example sentence: Water covers about 71% of Earth’s surface and is crucial for sustaining life.
