Mass has different definitions. The moon’s orbit confirms two are equivalent
Two ways of looking at mass match, squaring with theories of Newton and Einstein
![A photo of the moon as seen from Earth's orbit with the a blue haze at the bottom of the image.](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2023/07/071223_EV_moon-mass_feat.jpg?fit=1030%2C580&ssl=1)
Scientists used laser measurements of the moon’s orbit to compare two different types of mass, active and passive gravitational mass.
NASA