The stuff that we have left on the Moon and other bodies didn't certain me as much as the stuff in orbit....until I heard about the microbes! Ouch! I thought some spacecraft was sterilzed before launch. That seems like a good, especially if it is going to some place with an atmosphere.

But yet, this program talks about microbes that have survived on the moon and tomato seed in orbit. At least they can't grow there!

But on the orbiting junk, Dr. Gay said that changing orbits is easy if you are not in a hurry. That got me thinking about an automated system that could use solar sails to deorbit junk. Ideally, you like the sail to be able to deorbit some junk and then detach and change configuration to go back in orbit and move to the next object. Would that be possible?