meteorites activities 6 8

Investigate Meteorites

amnh.org/meteorites

ARTHUR ROSS HALL OF METEORITES Grades 6-8

2013 American Museum of Natural History. All rights reserved.

OverviewStudents will understand where meteorites come from, what they are made of, and what they tell scientists about planetary formation and Earths interior.

Before Your Visit: Students will read and discuss an informational text on the clues that meteorites provide about planetary formation and Earths interior.

During Your Visit: In the Arthur Ross Hall of Meteorites, students will explore and take notes on meteorites in three sections of the hall. Then, in the Gottesman Hall of Planet Earth, students will sketch and gather evidence about what meteorites reveal about planetary formation and Earths interior.

Back in the Classroom: Students will use what they learned from the reading and notes from their visit to the Museum to produce an illustrated text that defines meteorite; indicates where meteorites come from; and presents evidence on how different types of meteorites help us understand planetary formation and Earths interior (core, mantle, and crust).

Background for EducatorsThe most important clues from the early stages of the solar system come from meteorites. Some meteorites are older than the formation of Earth. They reveal how smaller bodies coalesced to form planets, and how our own planet developed after it formed.

Before Your VisitActivity: Reading

In this activity, students will read and discuss an informational text on the clues that meteorites provide about planetary formation and Earths interior.

Have students read What Is a Meteorite? independently. Ask them to use the large margin on the right-hand side of the page for note taking as they read. For example, ask them to underline and star key passages in the text and use the margin space to paraphrase the information they think is the most important. They may also use the space to draw diagrams of the processes they are reading about, or to write down questions about part of the text they dont understand.

Then use the prompts below to guide a class discussion:

What is a meteorite? (A meteorite is a rock that falls to Earth from space and refers only to those bodies that survive the trip through the atmosphere and reach Earths surface.)

How can studying meteorites from planets, the Moon, and some large asteroids help scientists understand Earths interior? (As the solar system formed, objects collided and stuck together, forming larger and larger bodies such as asteroids, planets, and the Moon. All of these partially or completely melted, and layers sepa-rated out. Dense, metallic materials sank to the center to form the core, while lighter materials formed the mantle. Further melting formed the rocky crust. This process is called differentiation. Study of meteorites from these differentiated bodies can help us to understand Earths interior since it too went through this process.)

What is an iron meteorite? What does studying this type of meteorite tell scientists about Earths core? (Iron meteorites are shattered fragments of the metal cores of differentiated asteroids or proto-planets. Scientists know from studying these meteorites that Earth has a center, or core, made of nickel and iron metal and that other planets have metal cores as well.)

NYS Science Core CurriculumPS 1.1c: The Sun and the planets that revolve around it are the major bodies in the solar system. Other members include comets, moons, and asteroids.

Plan how your students will explore the Arthur Ross Hall of Meteorites using the student worksheets.

Distribute copies of the worksheets to students before coming to the Museum. You may want to review the worksheets with them to make sure they understand what they are to do.

amnh.org/meteorites



What are the two types of stony meterorites? What do they tell us about the solar system and Earth? (Unmelted stony meteorites called chondrites tell us about the early solar system because they have remain unchanged. Partially melted stony meteorites, called achondrites, show that when planets and asteroids melted, they separated into metal and stony parts.)

What are stony-iron meteorites made of? What do some scientists theorize that pallasites show about Earths formation? (Stony-iron meteorites are a mixture of metal and rock. Some scientists theorize that pallasites are samples of the boundary between the metal core and the olivine-rich mantle around it.)

What are some things that the study of meteorites has helped scientists understand our solar system? (They provide evidence for the beginnings of our solar system, how planets and asteroids formed, and how impacts of large meteorites have altered Earths history and life on our planet.)

Activity: Explore Density

In this activity, students will investigate why some materials sink to the core of a planet while others float to the crust. This experiment uses marshmallow fluff and molasses to illustrate the concept of planet differentiation.sHave students determine the density of marshmallow fluff and molasses by filling identical beakers to the same level with each material and weighing both beakers. Then, place a dome of marshmallow fluff in the bottom of a clear bowl. Have students thin out fluff near edges and add molasses until it is about 3 deep. Ask students to predict what will happen and why. Then, observe what happens. Which material ends up on top? Why? Discuss the results with students and have them draw conclusions about why dense material is at the core of differentiated planets.

During Your Visit Arthur Ross Hall of Meteorites 1st floor (30-40 minutes)

In the Building Planets section of the hall, students will use the worksheet to sketch and gather evidence about what meteorites reveal about planetary formation and Earths interior.

Gottesman Hall of Planet Earth 1st floor (30 minutes)

Students will explore various sections of the hall to gather additional evidence about how scientists understand Earths interior:

In the How Earth Formed section, have students explore the density blocks and diagrams to understand more about how Earths layers are organized.

In the Earthquakes section, have students examine what seismic waves tell us about the make-up of Earths interior.

In the Volcanism sections, have students watch videos of scientists visiting lava flows to explore how lava flows help scientists understand the make-up of Earths interior.

Back in the ClassroomActivity: Write an Illustrated Text

Using what theyve learned from the pre-visit reading and their Museum visit, have students create an illustrated text that:

defines meteorite indicates where meteorites come from presents evidence on how different types of meteorites help us understand planetary formation and Earths

interior (core, mantle, and crust)

Student Reading

amnh.org/meteorites



Meteorites: Clues to Planetary Formation

What is a meteorite?

In simplest terms, a meteorite is a rock that falls to Earth from space. The word meteorite refers only to those rocks that survive the trip through the atmosphere and reach Earths surface.

Meteorites are rocks, but not like Earth rocks. Most meteorites are far older. They provide some of the only samples we have of other objects planets, asteroids, and possibly comets in our solar system. Some meteorites even contain tiny particles that formed around other stars that existed before our Sun. Studying meteorites helps us understand how the solar system and the bodies in it formed.

Where do meteorites come from?

Our solar system began to take shape some 4.6 billion years ago. At that time, the Sun and planets as we know them now did not exist. Back then a large cloud of gas and dust known as the solar nebula swirled around the developing Sun.

As the solar system formed within this swirling cloud, countless small objects collided and stuck together. Gradually, they formed larger and larger bodies such as asteroids and planets.

An artists rendering of the early solar system.Photo William K. Hartmann

amnh.org/meteorites



Some meteorites are pieces of planets, the Moon, and some large asteroids that show evidence of partial or complete melting within those bodies. This melting was the result of intense heat and pressure that occurred as the objects accreted. Accretion is when materials come together under the influence of gravity to form a planet, moon, asteroid, or comet. When the materials came together and the body increased in size, the heat and pressure increased. This caused melting. As this melting occurred, layers separated out in a process called differentiation. Dense metallic materials sank to the center where it crystallized to form the core. Less dense materials formed the mantle. Further melting formed the outer rocky crust. Meteorites from these differentiated bodies are rare finds but very valuable because they help us understand how planets formed and what their deep interiors are made of. What does studying different types of meteorites tell us?

Meteorites are all rocks from space. But they are not all alike. There are three main groups: iron meteorites, stony meteorites, and stony-iron meteorites. Each group of meteorites is split into many more classes and types. The class or type depends upon the minerals they contain, their chemistry and their structure. The different types provide us with information about a range of processes that occurred earlier in our solar systems history.

1. Stony Meteorites

The most common meteorites are stones. They could easily be mistaken for ordinary rocks from Earth. Stony meteorites fall into two main groups. Chondrites the more common type, are the oldest rocks formed in our solar system. These ancient stones offer a record of the solar system in its infancy. Since many have not changed, scientists use the age of these rocks to determine the age of our solar system. They are clues to what conditions were like when the solar system was young. They also give us hints about the elements that exist in our solar system.

Achondrites are pieces of planetary bodies that partially melted while they were in space, as described above. Studying these meteorites teaches us about the history of melting planetary bodies like Earth, the Moon, and the other rocky planets and moons.

Meteorites: Clues to Planetary Formation page 2

amnh.org/meteorites



2. Iron Meteorites

The meteorites known as irons are more than 98 percent metal. Almost every iron meteorite comes from the iron core of an asteroid or planetary bodies. As described above, the iron core formed when the asteroid differentiated. Study-ing these meteorites is one of the ways that scientists know that Earth has a core made of nickel and iron metal. The other planets have metal cores as well.

3. Stony-Iron Meteorites

Stony-iron meteorites are a mixture of metal and rock. There are two different kinds: mesosideroites and pallasites. The Stony-Iron meteorites called mesosiderites form when asteroids collide. In the crash, the molten metals and solid pieces of sili-cate rocks of both asteroids get mixed. Because of that, mesosiderites may record the history of both meteorites.

Other stony-iron meteorites are called pallasites. Pallasites contain green crystals of the mineral olivine that are surrounded by metal. These meteorites are extremely rare. They make up less than one percent of all known meteorites. Some scientists think that they resemble the material that makes up the boundary between Earths core (made of metal) and mantle (made mostly of olivine).

Meteorites: Clues to Planetary Formation page 3

Photo AMNH/D.Finnin

Go to the Building Planets section of the hall.

1. In the Crust exhibit, select a meteorite. Sketch and label it. What is the common rock type in these

meteorites?

Why did the rocky material rise to the surface

when the planets formed?

2. In the Mantle exhibit, select a meteorite. Sketch and label it.

What are these Stony-Iron Pallasite meteorites made of?

Where do they come from?

3. In the Core exhibit, select a meteorite. Sketch and label it.

What are these meteorites made of?


Student Worksheet

amnh.org/meteorites



Go to the Building Planets section of the hall.

1. In the Crust exhibit, select a meteorite. Sketch and label it. What is the common rock type in these

meteorites?

(basalt) Why did the rocky material rise to the surface

when the planets formed?

(It rose because it was less dense.)

2. In the Mantle exhibit, select a meteorite. Sketch and label it.

What are these Stony-Iron Pallasite meteorites made of?

(iron mixed with Olivine crystals)


(These meteorites come from the region between the crust and the core of a differentiated asteroid.)

3. In the Core exhibit, select a meteorite. Sketch and label it.

What are these meteorites made of?

(iron) Where do they come from?

(These meteorites come from shattered fragments of the metal cores of differentiated asteroids.)

Student Worksheet

amnh.org/meteorites



Answer Key

meteorites activities 6 8

Documents