# Seager Equation

Not Reviewed
N =
Rating
ID
EmilyB.Seager Equation
UUID
77d3f6dd-558d-11e6-9770-bc764e2038f2

The Seager Equation calculator estimates the number of habitable planets in a set of stars based on a number of  astronomical factors.

INSTRUCTIONS: Enter the following:

• (N*) This is the number of stars observed
• (FQ) This is the fraction of stars that are quiet
• (F(HZ)) This is the fraction of stars with rocky planets in the habitable zone
• (FO) This is the fraction of those planets that can be observed
• (FL) This is the fraction of planets that have life
• (FS) This is the fraction on which life produces a detectable signature gas

Habitable Planets (N): The calculator returns the number of habitable planets.

#### The Math / Science

The Seager Equation is a parallel version of the Drake Equation to estimate the number of  habitable planets in the galaxy. Where the Drake Equation  predicts the number of alien civilizations with radio technology, Seager has revised the Drake equation to focus on simply the presence of any alien life detectable from Earth. The equation focuses on the search for planets with biosignature gases, gases produced by life that can accumulate in a planet atmosphere to levels that can be detected with remote space telescopes.

The Seager Equation formula is:

N = N* • FQ • F(HZ) • FO • FL • FS

where:

• N = number of planets with detectable signs of life
• N* = number of stars observed
• FQ = fraction of stars that are quiet
• F(HZ) = fraction of stars with rocky planets in the habitable zone
• FO = fraction of those planets that can be observed
• FL = fraction of planets that have life
• FS = fraction on which life produces a detectable signature gas