Are we trashing the final frontier?

January 23, 2018 --As we push into the final frontier, we are leaving our mark. We have already left more than 400,000 pounds of human-made material on the moon. Rovers and bits of defunct orbiters litter the surface of Mars. And scientists have sent robotic spacecraft hurtling out past Pluto with no final destination. In our own cosmic backyard, space trash abounds.