Planet Albedo Calculator Formula

Understand the math behind the planet albedo calculator. Each variable explained with a worked example.

Formulas Used

Bond Albedo

albedo = reflected_flux / incident_flux

Absorbed Fraction

absorbed_fraction = 1 - reflected_flux / incident_flux

Variables

VariableDescriptionDefault
reflected_fluxReflected Flux(W/m2)100
incident_fluxIncident Flux(W/m2)1361

How It Works

Planet Albedo

Albedo quantifies how reflective a planet is. A value of 0 means all light is absorbed; 1 means all is reflected.

Formula

A = F_reflected / F_incident

The absorbed fraction is (1 - A), which determines how much stellar energy heats the planet.

Worked Example

Earth reflects about 100 W/m2 out of 1361 W/m2 incident.

reflected_flux = 100incident_flux = 1361
  1. 01A = F_reflected / F_incident
  2. 02A = 100 / 1361
  3. 03A = 0.0735
  4. 04This is geometric albedo at one angle; Bond albedo integrated over all angles is about 0.30

Frequently Asked Questions

What is the difference between bond albedo and geometric albedo?

Geometric albedo measures reflectivity at zero phase angle (full illumination). Bond albedo integrates over all phase angles and wavelengths, giving the total reflected fraction.

Which solar system body has the highest albedo?

Enceladus, Saturn's icy moon, with an albedo near 0.99 due to its bright ice surface.

How does albedo affect habitability?

Higher albedo means less absorbed energy and a cooler surface. Planets need the right albedo to maintain liquid water.

Ready to run the numbers?

Open Planet Albedo Calculator