![Space junk](/sites/default/files/styles/resource_card_image_360x300_/public/2019-10/space-junk-orbiting-earth.jpg?itok=nA6-Kgmi)
Space Junk
STEM Explained
Litter isn't just a problem on Earth. When litter ends up in space, it can cause collisions and other consequences for satellites, the International Space Station and even for people on Earth!
![Tennis Balls Tennis Balls](/sites/default/files/styles/resource_card_image_360x300_/public/PM_Tennis_Balls.jpg?itok=rGSq-yLm)
Bouncing Objects
Picture Collections
10 images of some spherical objects such as golf balls and tennis balls that are made of different materials and used for specific purposes
![How can you lift a marble off a table without touching it with your hands?](/sites/default/files/2019-08/how-can-you-lift-a-marble-off-a-table.jpg)
How can you lift a marble off a table without touching it with your hands?
Hands-on Activities
Is it magic? No - it’s physics! Use circular motion to overcome the force of gravity and amaze your family!
![Woodpecker on a tree](/sites/default/files/styles/resource_card_image_360x300_/public/2019-10/woodpecker-in-the-snow.jpg?itok=WmWgTEIl)
Do Woodpeckers Get Concussions?
STEM Explained
Pecking puts a lot of force on a woodpecker’s brain. But scientists think woodpecker bodies are adapted to help keep them from being injured during pecking-related collisions.
![Billiard balls and a cue stick on a felt-covered table (PIRO4D, Pixabay)](/sites/default/files/styles/resource_card_image_360x300_/public/2020-03/Billiard_balls_and_stick.jpg?itok=eHUZkzLE)
Billiards and Collisions
STEM Explained
The game of billiards shows the principles of collisions, momentum & impulse, and kinetics at work!