[tweet] … earth/Earth … lowercase except when you mean the planet we live on (sense 4 in M-W): http://bit.ly/bbUm2 …
The New York Times Manual of Style and Usage (1999) calls for “lowercase, except in the specialized context of astronomy, usually in juxtaposition with other bodies and without a preceding the: How do Mars and Earth fit into that pattern?” But even a casual look at recent copies of the paper tells you that this advice is widely ignored. The world has moved on. It is no longer 1999 … or 1988. (Do the math, M-W. That’s more than 20 years ago. M-W English Usage).
You can link to the National Geographic Society Style Manual from the Resources sidebar on the left to check the NGS take on this issue.
The Washington Post also capitalizes Earth when it means the planet we live on … and in contexts that have nothing to do with astronomy.
If you see earth and you could reasonably replace it with planet or the planet, then capitalize it.
If you see Earth (except in a name) and you couldn’t reasonably replace it with planet or the planet, then lowercase it. [M-W]
Note: See tweets… page.
Filed under: Dictionary, Style | Tagged: earth, word list | 1 Comment »