||Among the approximately earth-great
planets there are still a number of planets which
have a mass of earth about the size of the earth
and which have a certain similarity to the earth
in the orbit time around their central star, as
well as in the rotation time. Such planets are
referred to here as approximately earth-like
to the "Habitable Exoplanets Catalog" of
September 2015, 4 out of 10
habitable planets about the size of the earth can be
described as distant earth-like.
This corresponds to a share of 40 %. The probability
factor is Fa = 0.4 = 2:5.
According to the "Habitable Exoplanets Catalog"
of December 2017, 5 of 13
selected habitable planets about the size of the Earth
can be described as distant earth-like.
This corresponds to a share of 38.4 %. The probability
factor is Fa = 0.384,615 = 5:13.
If you calculate the mean value from both information,
||Fgm = 0.392,307
Fgm = 51:130
||39.23 % of all
habitable planets, in sun-like star
systems, are probably approximately
hen equation 2.4.2 can be used to extrapolate a
relationship for approximately earth-like planets
Related to all star systems A in our
galaxy, the number Nha of the solar-like star
systems, with habitable, approximately earth-like
planets, results to:
A · Fsph ·
A · Fs ·
Starting point are 100-300 billion solar systems, in the
galaxy, and inserting into equation 2.5.2 provides:
||There could be between 0.964
and 2.893 million approximately earth-like
habitable planets in solar-like star systems, in
The probability for habitable, approximately earth-like
planets, in solar-like star systems, in the galaxy, is
· Fh ·
Fha = Fsph·Fg·Fa
Fha= 1:15,000 · 1,212:3,286 · 51:130
As a result, only about every 103,664th
sun-like star system produces a approximately earth-like
planet in the habitable zone.