Save the Earth

Right now, there are more than 300,000 pieces of debris larger than a centimeter in diameter orbiting Earth.
They range from tiny shards of metal to deactivated, decades-old satellites. Most are shrapnel from discarded rocket stages that have exploded after use, or satellites that have collided. Colloquially, all this debris is usually called "space junk."
Together, the Department of Defense and NASA track the orbits of the 19,000 or so pieces of junk that are larger than a softball, alerting satellite operators when any satellite — including the International Space Station — is in danger, so they can move it.