The so-called wandering planets, which move in space on their own, and not around a single star, can be used by extraterrestrial civilizations as spacecraft for space exploration, says Irina Romanovskaya, professor of physics and astronomy at Houston Community College.
Romanovskaya’s article, devoted to new approaches to the search for extraterrestrial civilizations, was published in the International Journal of Astrobiology.
The professor believes that extraterrestrial civilizations, trying to create spacecraft for the interstellar migration of large populations, are likely to encounter insurmountable technical problems. And so they can use other methods of interstellar movement.
The researcher writes that “ETs may also use free-floating planets (roaming planets) as interstellar transport to reach, explore and colonize other planetary systems.”
With this method of movement, the professor of astronomy believes, aliens should produce various kinds of signals that can be recorded, in particular, an excess of infrared radiation and others.
Wandering planets can provide constant surface gravity, a large amount of space and resources, including water, Romanovskaya believes. And the source of energy in this case can be controlled thermonuclear fusion.
The astronomer lists what free-floating planets can do: transport large groups or populations when escaping impending existential threats, move unwanted populations, send large numbers of post-biological species to explore distant worlds or spread populations of their species to other planetary systems to save continuation of their civilization.
In addition, as Romanovskaya writes, “non-terrestrial civilizations can send space hitchhikers in the form of smart machines, probes and other technologies to explore stars, planetary systems and the interstellar medium.”
The scientist also notes that it is generally accepted that numerous free-floating planets should arise and be in star clusters. However, computer simulations of the Orion-Trapezium star cluster have shown that approximately 80% of its planets will immediately break away from their parent stars and leave the cluster.
As space researchers suggest, there are billions of free-floating planets. Extraterrestrial civilizations can take advantage of their close passage and send their species or technologies to them.
However, according to Romanovskaya, in general, such planets cannot serve as a permanent means of salvation, because due to the decrease in heat production in their depths, they cease to support oceans of liquid water.
“Consequently,” concludes the professor, “instead of making free-floating planets their permanent homes, extraterrestrial civilizations will use them as interstellar transport to reach and colonize other planetary systems.”
She also believes that highly developed civilizations are able to correct the orbit of any of the planets in their system and “push” it out.