Geomagnetism San Juan
By Geomagnetism Program
2011 (approx.)
Detailed Description
San Juan Observatory sign.
Sources/Usage
Public Domain.
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.
