<p>When we talk about &quot;albedo&quot; we normally think in terms of how much visible light is reflected.  A &quot;white&quot; object would reflect nearly all visible light, and have an albedo close to 1.</p>
<p>But that &quot;white&quot; object might absorb infra-red and ultra-violet light.  Consider the stuff that sunblock is made from.  It is white or transparent to visible light, but absorbs most UV.  It would appear black to a UV camera.</p>
<p>The bond albedo includes the absorption/reflection/re-emmision at all wavelengths.  It also includes the total absorbed or reflected at all angles. That's important because many objects are significantly retro-reflective and reflect more directly back than is scattered sidewise. If you want to know how bright an object will appear in your (visible light) telescope you want the ordinary albedo, but if you are interested in studying how warm a solar system body will be, then you need the bond albedo.</p>
<p>As a further example, the increase in CO2 in the Earth's atmosphere tends to lower the bond albedo. The Earth absorbs more of the sun's heat as a result of an increased greenhouse effect.  But as CO2 is transparent at visible wavelengths, it doesn't change the classical albedo.</p>

CC BY-SA 4.0
2024-05-22T18:44:37.460Z
Thanks a lot, very helpful. From what I understood then, even if albedo isn't defined for a specific wavelenght , it usually refers to visible light.
jack_O'Dim
CC BY-SA 4.0
2024-05-22T19:15:37.063Z
Yes, visible light, or implicitly "the wavelength at which one is observing"
James K
CC BY-SA 4.0
2024-05-20T18:34:51.547Z
2024-05-20T18:34:51.547Z
James K
<p>Recently I came across Bond albedo, but I am not sure I grasped the difference (if there is any) between it and the &quot;classical&quot; albedo. Thanks in advance</p>

<photometry><electromagnetic-spectrum><albedo>
What is the difference between albedo and Bond albedo?
jack_O'Dim
# What is the difference between albedo and Bond albedo?

(Asked by: username_0 on 2024-05-19)

Recently I came across Bond albedo, but I am not sure I grasped the difference (if there is any) between it and the "classical" albedo. Thanks in advance

**Tags:** photometry, electromagnetic-spectrum, albedo

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## 1 answers

### Answer by username_1 on 2024-05-20. Score: 4 | Accepted answer

When we talk about "albedo" we normally think in terms of how much visible light is reflected. A "white" object would reflect nearly all visible light, and have an albedo close to 1.

But that "white" object might absorb infra-red and ultra-violet light. Consider the stuff that sunblock is made from. It is white or transparent to visible light, but absorbs most UV. It would appear black to a UV camera.

The bond albedo includes the absorption/reflection/re-emmision at all wavelengths. It also includes the total absorbed or reflected at all angles. That's important because many objects are significantly retro-reflective and reflect more directly back than is scattered sidewise. If you want to know how bright an object will appear in your (visible light) telescope you want the ordinary albedo, but if you are interested in studying how warm a solar system body will be, then you need the bond albedo.

As a further example, the increase in CO2 in the Earth's atmosphere tends to lower the bond albedo. The Earth absorbs more of the sun's heat as a result of an increased greenhouse effect. But as CO2 is transparent at visible wavelengths, it doesn't change the classical albedo.

> **Comments:**
> **username_0**: Thanks a lot, very helpful. From what I understood then, even if albedo isn't defined for a specific wavelenght , it usually refers to visible light.  
> **username_1**: Yes, visible light, or implicitly "the wavelength at which one is observing"  

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