Halc

If you want a more accurate mass estimate, multiply the surface area by the pressure at an altitude of something like 400m, which is close to the average altitude where the atmosphere ends worldwide.

Not saying Earth masses less than the atmosphere. Earth is in freefall, hence has no weight. You can place Earth on top of me, in which case it would weigh about 900 Newtons, still considerably less than the atmosphere collective weight. A 20 digit number of Newtons is more weight than zero. On the other hand, weight is a force, no? Force is a vector, and adding all the force applied by the atmosphere pretty much (not completely) cancels itself out, leaving many fewer digits of actual net force (weight?) on Earth.

Venus orbits the same direction as all the other planets. But it spins on its own axis backwards, so it has one more day per year than its sidereal spin rate, as opposed to one less like all the other planets. Earth for instance experiences 365.25 days per year, but spins at a rate of about 366.25 times. Venus spins so slow that it goes around about once per Venus year, giving it just two days in its year.

First of all, weight is a force, measured in say Newtons. I did the pressure * area thing and got 5.1x10^19 Newtons. That's far heavier than Earth itself since Earth, unlike the atmosphere, is not resting on anything and is thus weightless. This is my first test post and it didn't take the html ¹⁹