A person holds in the palm of their hand a model asteroid adorned with beads, a metal nut, and rocks.


Students will shape their own asteroid models out of clay as a hands-on lesson in how asteroids form, what they are made of, and where they can be found in our Solar System.



  • Materials can vary, but provide several options so students can make intentional choices about the asteroid type they are modeling.


Asteroids are rocky and metallic, airless worlds that orbit our Sun, but are too small to be called planets. They are remnants left over from the early formation of our solar system, about 4.6 billion years ago. Tens of thousands of these small bodies are gathered in the main asteroid belt, a vast doughnut-shaped ring between the orbits of Mars and Jupiter. Asteroids that pass close to Earth are called near-Earth objects.

A large asteroid is depicted in space next to a much smaller asteroid.

This color picture is made from images taken by the imaging system on the Galileo spacecraft about 14 minutes before its closest approach to asteroid 243 Ida on August 28, 1993. The range from the spacecraft was about 10,500 kilometers (6,500 miles). | + Expand image

NASA has sent several spacecraft to study asteroids, including the NEAR Shoemaker probe – the first to orbit an asteroid – and OSIRIS-REx, which will return an asteroid sample to Earth. The Psyche mission will visit the asteroid Psyche to help scientists learn more about the metal-rich body, better understand the history of the solar system, and potentially gain insight into the interior of Earth.

An illustration shows the asteroid Psyche in space with stars in the background.

This illustration depicts the metal-rich asteroid Psyche, which is located in the main asteroid belt between Mars and Jupiter. | + Expand image

Asteroids become meteors – or shooting stars – when they fall through a planet's atmosphere, leaving a bright trail as they are heated to incandescence by the pressure and friction of the atmosphere. Pieces that survive the journey and hit the ground are called meteorites.

A thin streak of light spreads across the night sky. Snow and trees are visible in the foreground.

A meteor streaks through the night sky. | + Expand image

Meteorites may vary in size from tiny grains to large boulders. One of the largest meteorites found on Earth is the Hoba meteorite from southwest Africa, which weighs roughly 119,000 pounds (54,000 kg).

A dark meteorite is visible in the foreground resting on light colored sand. The legs of someone approaching are visible in the background.

Peter Jenniskens, meteor astronomer at NASA Ames Research Center and the SETI Institute Mountain View, Calif., walks toward a meteorite that landed in the Nubian Desert of northern Sudan | + Expand image


  1. Lead a discussion with students to explain that asteroids are rocky and metallic fragments left over from the formation of the solar system, about 4.6 billion years ago. They can be cratered or smooth, and are generally made up of a variety of rocks, ice, dirt, dust and sometimes metal.
  2. Provide students with two or more pieces of clay, as well as a selection of foil, pebbles, beads or other small objects.
  3. A person pushes colorful beads into a neon green piece of clay adorned with rocks.

    Adding objects to the clay. Image credit: NASA/JPL-Caltech | + Expand image

  4. Have students mold the clay as they like and add pebbles, beads or other small materials. They can color the asteroids with markers.
  5. A person wraps their hands around a model asteroid adorned with beads, a metal nut, and rocks.

    Molding the asteroid model to create a desired shape. Image credit: NASA/JPL-Caltech | + Expand image

  6. Pull up images of real asteroids and ask students to compare their asteroids to real ones. Download images from the JPL images gallery or the NASA Solar System Exploration website.
  7. A neon green clay asteroid with small objects on its surface is shown next to a black and white image of a very rocky asteroid that is shaped like a cross between a squished sphere and a diamond with rounded corners.

    An asteroid model compared with a real image of asteroid Bennu captured by NASA's OSIRIS-REx spacecraft in 2018. Image credit: NASA/JPL-Caltech/Goddard/University of Arizona | + Expand image | › Bennu image and caption


  • Which materials did you choose to build your asteroid? Why did you choose them?
    A group of six students around a wooden table holds up thier playdough asteroid models and smile. Colorful drawings are displayed on the wall behind them.

    Students in Mrs. Lauren Manning's fourth grade class at Carpenter Community Charter in Studio City, California, show off their asteroid models. Image courtesy Lauren Manning. | + Expand image

  • Compare your asteroid to other asteroids. How is your asteroid similar? How is it different?
    Several asteroids made of colorful playdough decorated with beads and rocks.

    A close-up view of the asteroid models made by students in Mrs. Manning's class. Image courtesy Lauren Manning. | + Expand image


  • Students should have sound reasoning for why those chose the materials they selected for their asteroid.
  • Student comparisons should accurately reflect similarities and differences between their asteroid and selected asteroid images.


Older students can measure the mass of a model with a scale and the volume by measuring how much water it displaces, then calculate and compare densities of different models.

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