From the June 2009 issue

How do scientists determine the elevations of mountains and other topography on the Moon, Mars, and other places where there is no sea level as the reference point?

Joe Tepera, Muenster, Texas
By | Published: June 22, 2009 | Last updated on May 18, 2023
Earth and Moon
This image shows a partial view of Earth as well as the Moon in the background.

Elsewhere in the solar system, where there are no standing bodies of water, we normally use the planet or moon’s average radius as a reference for measuring elevation.