Home
Back
Planetary Temperature Equation:
| From: | To: |
The planetary temperature equation estimates the equilibrium temperature of a planet based on its distance from a star, the star's luminosity, the planet's albedo (reflectivity), and fundamental physical constants. This calculation assumes the planet is in radiative equilibrium with its star.
The calculator uses the planetary temperature equation:
Where:
Explanation: The equation balances the incoming stellar radiation (adjusted for albedo) with the outgoing thermal radiation from the planet.
Details: Calculating a planet's equilibrium temperature helps astronomers determine potential habitability, atmospheric composition, and energy balance. It's a fundamental calculation in exoplanet studies.
Tips: Enter star's luminosity in watts, albedo as a value between 0 (perfect absorber) and 1 (perfect reflector), Stefan-Boltzmann constant (default value provided), and distance in meters. All values must be positive.
Q1: Why is this an equilibrium temperature?
A: This calculation assumes the planet has reached a steady state where incoming and outgoing radiation are balanced, ignoring atmospheric effects.
Q2: How does albedo affect temperature?
A: Higher albedo means more radiation is reflected, leading to lower temperatures. An albedo of 1 would mean all radiation is reflected.
Q3: What's a typical value for solar luminosity?
A: Our Sun's luminosity is approximately 3.828×10²⁶ W. For other stars, values vary widely.
Q4: Why is distance squared in the equation?
A: Radiation follows an inverse-square law, spreading out over a sphere's surface area (4πD²).
Q5: How accurate is this for real planets?
A: This gives a basic estimate. Real temperatures are affected by atmosphere, rotation, internal heat, and other factors.