Probabilities in the Galaxy

Superearths are planets with at least four times the earth's mass. Most of the superearths are in a range of 4 to 20 earth masses. However, there are also specimens of up to 40 earth masses. Most of the superearths are about the size of the earth or at most twice as large.

According to the "Habitable Exoplanets Catalog" of September 2015, 21 of 31 habitable planets are so-called superearths.
This corresponds to a share of 67.741 %. The probability factor is therefore F_hsup = 0.677,419 = 21:31.

According to the "Habitable Exoplanets Catalog" of December 2017, 30 of 53 habitable planets are superearths. This corresponds to a share of 56.603 %. The probability factor is therefore F_hsup = 0.566,037 = 30:53.

If you calculate the mean value from both information, you get:

Then, from equation 1.6.1 for solar-like star systems that have habitable planets, a relationship for superearth can also be derived.
Related to all star systems A in our galaxy, the number N_hsup of the G-star systems, with habitable super-earths, results to:

Starting point are 100-300 billion solar systems in the galaxy. Insert into equation 2.3.2:

The probability for habitable superearths in solar-like star systems, in the galaxy, is then:

F_sup = 1:15,000 · 2,043:3,286
F_sup = 0.000,041,449 = 1:24,126

Among about 24,126 sun-like star systems, one exists, with a superearth.


In principle, there is no reason why simple life, in the form of flora, can also develop on superearth. However, because of the high gravity, it is doubtful whether intelligence and civilization can really develop on such planets. More likely are civilizations on approximately earth-great planets and approximately earth-like planets.

From the existing catalogue data, two further probabilities can be extracted for planets that can be used as life carriers, namely for approximately earth-great planets and approximately earth-like planets.

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