High-speed collisions in space
Experiments with a carrot gun
About this video
Andy uses a carrot gun to discuss the hazards of micrometeoroid impacts in space, showing that at high enough speeds even tiny specks of dust can be dangerous. Why do high energy collisions in space make solid matter behave in a way that's wholly unfamiliar to us?
Our piece of equipment fires a carrot at over 300 km per hour. At that speed, the humble carrot can inflict serious damage on anything that gets in its way. And yet that’s just a fraction of the speed of objects in orbit around the Earth. For example, the International Space Station travels 100 times faster, at about 8 km per second.
To understand why moving at such high speeds makes collisions so deadly, we have to consider what matter really is. Andy suggests that matter as we’re familiar with it is really determined by the chemical bonds that holds it together, rather than the atoms and molecules themselves. At extreme speeds, collisions have so much kinetic energy that all of an object’s chemical bonds are likely to be broken, in effect resulting in a high-energy explosion as unbound atoms hurtle out in all directions.
So how do spacecraft protect themselves from these superfast threats? One approach is to use a Whipple shield – two layers of shield separated by a gap.