Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The map originates from “Blue Marble: Land Surface, Shallow Water, and Shaded Topography” (Visible Earth, NASA); all modifications were performed using Adobe Photoshop CS6.
