As you and your students may be able to imagine, our planet is filled with trash. Most of what we consume today is considered not to be used more than a few times, and so we throw it in a trash can and then put it on the street for the trash men to take it far away from us. Unfortunately, this is not the whole truth, it ends up in our quickly filling land fills.
But we do not only occupy this planet. For the past fifty or so years we, or things we have made, have also occupied outer space. Some of these items have been brought back, others have been destroyed reentering our atmosphere. But many are still floating in outer space. And even the tiniest object can cause major damage. Have you students imagine sand being thrown at them. Then imagine it being thrown at you at around 17,000 mph, the average speed of a space craft in low orbit. It can cause a lot of damage to you, or to a space craft.
This infographic goes through various methods being explored and tested to help clean up this debris. From giant fish nets to lasers, there are a variety of ways being explored to make space safe for continued exploration. Have you students discuss the merits of each method, and be able to defend what they think is the best method.