Moon

[Dual]

When the astronauts left that plaque and American flag on the moon, they disrupted a balance that had been in place for billions of years. The Earth lost a small piece of mass, and the moon gained some. What does this mean? In the long term, the differential will cause the moon to spin further and further out of Earth's orbit, until we're left with a dark night sky.

 

[Cassie]

Don't forget about all that stuff they sent to Mars and Saturn! ALSO, all the satellites and junk orbiting the earth!

The earth gets bombarded with stuff from space everyday and night, it has probably already regained the mass it lost with that flag.

 

[Mentalist]

Earth gains mass all the time from space debris. Thousands of tons of the stuff. Solar winds blow parts of the upper atmosphere in to space slightly decreasing the mass of Earth as well. So it's constantly fluctuating.

 

[CaptainWacky]

I thought the moon had been moving away from the Earth for millennia anyway. I saw it on QI.