What does albedo measure in astronomy?

Albedo is a crucial concept in astronomy that quantifies how much light a celestial body reflects compared to the amount of light it receives from the Sun or another light source. Specifically, it is expressed as a ratio or percentage, where a higher albedo indicates that the body reflects a greater proportion of incoming light. For instance, a body with an albedo of 0.3 reflects 30% of the light it receives, while absorbing the remaining 70%.

This measurement is significant for understanding the physical properties of planets, moons, and other celestial objects, including their surface composition and temperature. For example, objects with a high albedo, such as ice or clouds, can reflect much of the sunlight and appear brighter, while those with a low albedo, like rocky surfaces, absorb more light and appear darker. Understanding albedo helps astronomers interpret data regarding climate and environmental conditions on various celestial bodies.