Fermi Paradox: Sun may be too short-lived for extraterrestrial colonization

For decades people have been puzzling over why the Milky Way is apparently not populated. But maybe it is, and sun-like stars have been left out.

It is possible that the Milky Way has long been settled by one or more extraterrestrial civilizations and the solar system has been bypassed because the end is already too close. This is the main argument of a scientific paper that proposes a new explanation for the so-called Fermi paradox. Accordingly, the Milky Way should have been settled long ago; that this is obviously not the case requires an explanation. Two US scientists now think that smaller stars – especially orange-colored dwarf stars – are much more suitable for colonization, partly because they have a significantly longer life expectancy of up to 70 billion years.

Are Sun-Like Stars Dying Too Young?

Jacob Haqq Misra and Thomas Fauchez explain in the study accepted for publication in the Astronomical Journal that main sequence stars of the spectral class K and orange dwarfs, respectively, are ideal migration targets for civilizations that arose around a sun-like star. So those in the Milky Way are about twice as common. At the same time, they are much quieter than the particularly common red dwarfs. In addition, exoplanets have already been discovered there that lie in the habitable zone but do not always face the star in the same way, as is usually the case with red dwarf stars. A move to such a star is therefore easier overall.

There are certainly good reasons to colonize sun-like star systems, but since that has apparently not happened in the solar system, one possible explanation is that extraterrestrials have different preferences. An expansion of extraterrestrials across the entire Milky Way thus remains possible overall. According to the current state of knowledge, however, scenarios in which all yellow dwarf stars – including the sun – were settled could be ruled out. Their work now opens up the possibility that all Orange Dwarfs were settled instead. These stars are therefore ideal targets for searching for so-called bio and techno signatures, even if this is comparatively more difficult due to the properties of the stars.

The Fermi paradox has occupied scientists for over 70 years. In 1950, over dinner and after a discussion about extraterrestrials, the physicist Enrico Fermi asked: “Where is everyone?” Since then there have been various attempts to explain why we have not discovered any evidence of an extraterrestrial civilization. Again and again it is determined that a space-faring civilization can colonize a galaxy like the Milky Way even with conservative assumptions in comparatively clear periods of time and that this should have happened long ago. Recent studies, therefore, come to the conclusion – such as Haqq Misra and Fauchez now – that systems like that of our sun could not be considered for various reasons.