Is the earth getting heavier or lighter?

Dear Cecil: Is the earth getting heavier or lighter? After all, we’ve littered the cosmos with a lot of NASA stuff, which should shave off a few pounds, along with vapor escaping from the atmosphere. On the other hand, there’s a lot more people and meteorites around than there was in 8011 BC. What do you think? Edward M. Smith Jr., Los Angeles

Cecil replies:

Puny humanoid, you think the pitiful efforts of mankind have appreciably altered the mass of the earth, reliably estimated at 6 sextillion, 588 quintillion tons? (And man, if you don’t think it was a bitch getting that puppy on the scale …) If so, shed your illusions. It’s believed the earth gains anywhere from several dozen to several hundred tons per day due to meteorites and meteoritic dust — 10,000 to 100,000 tons a year. (Sorry, but estimates vary widely.) This far exceeds any losses. The weight of the people, incidentally, has increased the mass of the earth by zero, for the obvious reason that we are but dust, and unto dust we shall return. To put it another way, human cells are merely rearrangements of the compounds previously found (i.e., before dinner time) in plant cells and animal cells. Net change pound-wise, nada.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.