albedo

American  

[al-bee-doh] / ælˈbi doʊ /

noun

plural

albedos

1. Astronomy. the ratio of the light reflected by a planet or satellite to that received by it.

2. Meteorology. such a ratio for any part of the earth's surface or atmosphere.

3. pith.

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albedo British  

/ ælˈbiːdəʊ /

noun

1. the ratio of the intensity of light reflected from an object, such as a planet, to that of the light it receives from the sun

2. physics the probability that a neutron passing through a surface will return through that surface

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albedo Scientific  

/ ăl-bē′dō /

1. The fraction of the total light striking a surface that gets reflected from that surface. An object that has a high albedo (near 1) is very bright; an object that has a low albedo (near 0) is dark. The Earth's albedo is about 0.37. The Moon's is about 0.12.

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Etymology

Origin of albedo

First recorded in 1855–60; from Late Latin albēdō “white (color), whiteness,” equivalent to alb(us) “white” + -ēdō noun suffix; cf. torpedo

Explanation

Albedo refers to how reflective and bright something is. Snow has a high albedo, which is why skiers wear sunglasses and sunscreen. Technically speaking, the albedo of an object is a ratio. It compares the amount of light hitting the surface of the object to the amount of light that gets reflected back. The more light reflected, the higher the albedo. Scientists often use this word in reference to the surfaces of planets and other reflective objects in the night sky. Albedo comes from a Latin word for “white.”

Example Sentences

"Water vapor does not affect the albedo of Earth, so it did not affect our analysis of the magnitude of the aerosol forcing."

From Salon • Feb. 6, 2025

"We had already observed a slight decline in recent years. The data indicates that in 2023, the planetary albedo may have been at its lowest since at least 1940."

From Science Daily • Dec. 5, 2024

Planetary albedo describes the percentage of incoming solar radiation that is reflected back into space after all interactions with the atmosphere and the surface of the Earth.

From Science Daily • Dec. 5, 2024

Other potential outcomes include reductions in albedo — or the amount of light reflected by the ice — which would accelerate human-caused warming by creating an amplifying feedback loop.

From Los Angeles Times • Mar. 5, 2024

The earth’s albedo is four times that of the moon, which means it shines four times as brightly.

From "Flying to the Moon: An Astronaut's Story" by Michael Collins