The gravity traps everythings on a planet.
nose hairs
because of the sand particles
planet venus
snot
mucus
Venus
Cilia acts like a filter. It traps dirt particles that we inhale and moves these particles out of the body.
The Greenhouse effect...
Saturn
The planet Venus is completely covered with clouds. The clouds are comprised of sulfuric acid, which traps in the atmosphere and heat.
Greenhouse effect.
A greenhouse effect traps heat that would otherwise escape out to space, so it keeps the planet warm.