From the July 2011 issue

On Earth, scientists measure the heights of mountains with respect to sea level. What baseline do they use on other planets or moons?

Vishal Padwal, Jersey City, New Jersey
By | Published: July 25, 2011 | Last updated on May 18, 2023
globe_west
NASA

The short answer is that even though other planets don’t have oceans like Earth, we can still calculate the level an ocean would have and use that as a baseline.