Every action has an equal and opposite reaction. This is true everywhere, but it nowhere more obvious than in space. Click "Throw!" to have the astronaut throw a rock to the right. When she pushes on the rock to throw it, the rock pushes back on her. This moves the rock to the right and the astronaut to the left. Try to change the speed of the throw or how massive the rock is. What changes about the astronaut?
Created for the UBC Physics Outreach webpage: https://outreach.phas.ubc.ca/phenomenal-physics-astronomy-at-home/challenge-no-6-build-your-own-rocket/