The Goldilocks Zone calculator returns the orbital range around a star where habitable life, as we know it, is possible.
INSTRUCTIONS: Choose units and enter the following:
Goldilocks Zone Range (d): The calculator returns the minimum and maximum semi-major axes (approximate radii) in astronomical units. However, this can be automatically converted to compatible distance units via the pull-down menu.
The Goldilocks Zone calculator estimates the minimum and maximum distance from a star in which you can place a habitable planet. It's based on the idea that the mean planetary temperature must be between the freezing point of water (0° C = 273 K) and the boiling point of water (100° C = 373 K). The formula used inverts the one in the Planetary Temperature calculator to find the minimum and maximum distances. In the formula given above, F0 is the solar constant (1361 W/m2), the flux of light from the sun at Earth's distance from it (1 AU = 1.5x1011 m).
The formula for the Goldilocks Zone is:
`d = ((L*F_0)/(4\sigma T^4)(1-a)(1+(3/4)\tau))^(1/2)`
The parameters you input are:
The calculator's outputs are:
By default, the answers are given in astronomical units, but you can convert them into any units of distance you want.