Earth Day Activity: Protect the Earth from Asteroids

What can we use instead of the small foam ball or marbles if those are hard to find?

Use a ping-pong ball or tightly crumpled aluminum foil wrapped with tape for the Earth and small beads or polished pebbles in place of marbles when you place the decorated Earth ball in the center and roll marbles from the starting line.

The marble keeps rolling past the tray or the ramp keeps falling—how can we fix that?

Make sure the tray is on a clear, level workspace, press extra tape under and along the folded cardboard ramp where you tape it to the tray, and anchor the Earth foam ball with a dab of playdough so the marble's stop point that you mark with a pencil dot is consistent.

How can I adapt this activity for younger children or older kids who want a bigger challenge?

For younger kids, prefold the cardboard ramp, use larger balls instead of marbles, and let them color the foam Earth and draw the orbit, while older kids can measure ramp angles with a protractor, record multiple trial distances after rolling from the starting line, and compare results.

What are some fun ways to extend or personalize the tabletop Earth and asteroid experiment?

Try adding multiple taped cardboard ramps to test different deflection strategies, swap marbles for different-sized 'asteroids' to see how outcomes change, paint the tray as space, time marble runs with a stopwatch, and photograph your finished tabletop Earth to share on DIY.org.