What will happen in the next five billion years, when the sun turns into a red giant and consumes the Earth? Scientists have been grappling with this question for a long time. Will this event cause the extinction of the human race from the universe? Or is there a way to save the species from this apocalypse? Interstellar travel to a suitable planet that could be humans’ next home is a hypothetical way to save humanity. But is this actually possible? Even if we found such a planet, it would take us hundreds and thousands of years to travel through spaceships to reach it.
This means that it will take humans several generations to find a new home. However, a recent research paper suggests that interstellar travel may be possible even without spaceships.
A new research paper published in International Journal of Astrobiology He says that extraterrestrial civilizations may not need spaceships to travel to another star system.
According to her theory, extraterrestrial and alien civilizations could use free-floating planets as interstellar transportation to visit, explore, and colonize planetary systems, author Irina Romanovskaya, professor of physics and astronomy at Houston Community College, writes in the paper. These floating planets are also known as rogue planets.
Romanovskaya added that she suggests technological signatures and hypothetical artifacts of extraterrestrial civilizations for interstellar migration and colonization using freely floating planets, as well as ways to trace their technological footprints and artefacts.
According to the author, rogue planets are capable of providing constant surface gravity and large amounts of space and resources.
In 2021, researchers discovered between 70 and 170 rogue planets in one region of the Milky Way. In 2020, a study suggested that there are up to 50 billion rogue planets in our galaxy.
The author explained four scenarios where rogue planets could be used for interstellar travel. However, she noted, “Floating planets may not serve as a permanent way to escape existential threats.”
The first scenario concerns a rogue planet passing near the home world of an extraterrestrial civilization. The frequency with which this occurs is determined by the number of rogue planets in general.
In the second scenario, technology is used to steer a rogue planet closer to the home of civilization. They can pick an object from their Oort cloud – if they have one – and use a propulsion system to send it into a safe orbit around their planet if they have enough technology.
The third scenario is very similar to the second scenario. It also includes an object from the most remote regions of solar civilization. Romanovskaya cites our small solar system planet Sedna as an example.
The fourth scenario also includes Sedna-like beings. As the star deviates from the main sequence and expands, a critical distance is reached after which objects are ejected from the system rather than remaining gravitationally bound to the dying star.
A rogue planet isn’t a permanent home in any of these conditions, it’s just a lifeboat.