For what it's worth, estimated combined mass of all currently cataloged asteroids in our system (currently just over 1 million) is less than our moon's.
Edit: just found my notes. Awhile back I tried to reason out how fast we'd get in orbital trouble if we started ejecting all of our garbage into the sun, just an academic exercise. Rough estimate by an established astronomer [1] was that we're safe in the 0.95 AU - 1.69 AU range, so our orbit could vary from -7.25 mil km to +54.7 mil. km and we'd stay within the habitable zone. After that I plugged known values into an orbital simulator [2] and eyeballed how much mass loss that'd have to be and how long it would take.
5,973,600,000,000,000,000,000,000 (kg) mass of the earth
597,360,000,000,000,000,000 (kg) we're in slight trouble at 0.0001 loss
50,000,000 (kg) per year normal loss to space
126,642,989,704 (kg) garbage landfilled per year
242,944,073,372 (kg) handled total per year
World est: 2,010,000,000,000 (kg) per year (300 mil years!)
Another astronomer on mass: "If the force of gravity was halved, [Earth's] speed would be exactly the escape speed. In fact, any body orbiting in a circular orbit would become unbound if the force of gravity was reduced by a factor of two"
Doubling mass of our moon wouldn't change the orbit: https://public.nrao.edu/ask/what-would-happen-to-the-orbit-o...
Edit: just found my notes. Awhile back I tried to reason out how fast we'd get in orbital trouble if we started ejecting all of our garbage into the sun, just an academic exercise. Rough estimate by an established astronomer [1] was that we're safe in the 0.95 AU - 1.69 AU range, so our orbit could vary from -7.25 mil km to +54.7 mil. km and we'd stay within the habitable zone. After that I plugged known values into an orbital simulator [2] and eyeballed how much mass loss that'd have to be and how long it would take.
Another astronomer on mass: "If the force of gravity was halved, [Earth's] speed would be exactly the escape speed. In fact, any body orbiting in a circular orbit would become unbound if the force of gravity was reduced by a factor of two"
[1] http://curious.astro.cornell.edu/our-solar-system/39-our-sol...
[2] http://orbitsimulator.com/gsim.html