In around 5 billion years, the Sun will exit the main sequence and become a red giant. Mercury, Venus, Earth, and maybe Mars will be eaten and destroyed as it enlarges and turns into a dark, demonic sphere.
Is it conceivable for humanity to survive the red giant phase of the Sun? Extraterrestrial Civilizations may have before encountered this grave menace (ETCs).
Could they have avoided employing spacecraft by migrating to a different star system?
Universe Problems associated with interstellar travel are well-known to modern readers. The Alpha Centauri system is the closest solar system to our own.
It would take more than four years to reach Alpha Centauri, supposing we could move at the speed of light.
At our current technological level, it still takes five years to send an orbiter to Jupiter. There is a great deal of talk about generation starships, where mankind may spend generations en route to a distant habitable planet.
Instead of flying at near-light speed, whole generations of mankind would journey to another star over the course of centuries or millennia. It’s fun to ponder, but at this point it’s still pure speculation.
Exists any alternative means for us and other civilizations to escape our deadly situations?
According to the author of a recent research published in the International Journal of Astrobiology, ETCs may not require starships to move to another star system and avoid existential threats.
Instead, they may utilise rogue planets or planets in free-floating orbit. According to the research, “Migrating extraterrestrial civilizations and interplanetary colonisation: implications for SETI and SETA” Irina Romanovskaya authored the work. Romanovskaya is a physics and astronomy professor at Houston Community College.
I propose that alien civilizations use free-floating planets as interstellar transportation to explore, examine, and colonise planetary systems, as stated by Romanovskaya. In the search for extraterrestrial civilizations, these actions may also leave technosignatures and remnants.
She remarked, “I propose the technosignatures and artefacts of possible extraterrestrial civilizations for interstellar migration and interstellar colonisation utilising free-floating planets, as well as methods for locating such technosignatures.”
It is possible that rogue planets in the Milky Way or other billions of galaxies have their own life in oceans kept warm by radioactive decay.
If they hit with a star and become gravitationally bound, life will have effectively used an errant planet to relocate to a more advantageous place. Why then can’t a culture do the same?
Free-floating planets are believed to be dark, frigid, and hostile. Unless they have subsurface waters that are heated, that is. However, they do offer certain advantages.
Free-floating planets can provide constant surface gravity, vast amounts of space, and resources, according to Romanovskaya. Free-floating planets with surface and subterranean oceans can supply water as a consumable resource as well as protection from space radiation.
An advanced civilization may design the earth for better advantage by guiding the globe and providing energy sources. If we are on the verge of adopting controlled fusion, Romanovskaya believes that advanced civilizations may already be using it, which might make a planet that is now frozen livable.
The author presents four scenarios in which ETCs may profit from rogue planets.
The initial scenario concerns a renegade planet travelling through the home planet of an ETC. The frequency of this occurrence is governed by the total number of rogue planets.
We are unsure of the exact number, but we know there are some. In 2021, a team of astronomers announced the discovery of 70 to 170 Jupiter-sized rogue planets in one region of the Milky Way. According to one study, there might be up to 50 billion of them in our galaxy by the year 2020.
What is the origin of everyone? Most are likely ejected from their solar systems as a result of gravitational processes, although some may arise in the same manner as stars, through accretion.
The Oort Cloud is another source of rogue planets in our Solar System. If further systems include comparable clouds of debris, they may contain a plethora of planets ejected from stars due to stellar activity.
“Stars of 1–7 times solar mass undergoing post-main-sequence growth, as well as a supernova from a 7–20 times solar mass progenitor, are able to evacuate Oort-cloud debris from their systems,” says Romanovskaya.
But how often can an ETC or our civilization anticipate hitching a trip on a rogue planet? 70,000 years ago, the binary star W0720 (Scholz’s star) traversed the Oort Cloud in our Solar System, according to a 2015 study.
Although it was a star and not a planet, this indicates that objects pass close by. If the studies projecting billions of free-floating planets are accurate, then some of them passed close to or directly through the Oort Cloud before humanity had the technology to discover them.
Even if the Oort Cloud is far away, a highly developed civilization may be able to detect an approaching rogue planet and go to meet it.
In the second scenario, technology is employed to lead a planet closer to the home of a civilisation. If they had sufficient technology, they could select an item from their own Oort Cloud and use a propulsion device to send it into a safe orbit around their planet.
With sufficient planning, they may modify the object to suit their needs, for instance by constructing underground shelters and other infrastructure. With sufficient technology, they might perhaps alter or create an environment.
The third circumstance is pretty comparable to the first. It also involves a corpse from the outermost limits of the civilization’s Solar System. As an example, Romanovskaya offers the tiny planet Sedna in our Solar System.
In about 11,000 years, Sedna’s orbit will carry it from 76 astronomical units to 937 astronomical units. With sufficient technology and time, a Sedna-like object may be transformed into an escape spacecraft.
The author states, “civilizations capable of doing so would be advanced civilizations that had previously explored their planetary systems to at least 60 AU from their home stars.”
There are several potential complications. Introducing a dwarf planet from the furthest reaches of the Solar System into the inner Solar System might generate a multitude of issues by perturbing the orbits of existing planets.
Threats are diminished, however, if a civilization orbiting a post-main sequence star has already migrated outward with the altering habitable zone. In her study, Romanovskaya goes into further detail on the required energy and time.
The fourth scenario contains elements similar to Sedna. When a star deviates from the main sequence and expands, a threshold distance is achieved beyond which objects are evacuated from the system instead of staying gravitationally bound to the dying star.
If an ETC could foresee when these objects would be ejected as rogue planets, they might prepare ahead and use them to escape the dying solar system. This might be highly risky, as periods of violent mass loss from the star represent a substantial threat.
In all of these situations, the renegade planet or other body is not a permanent habitation; it is only a lifeboat.
The author contends that free-floating planets may not provide a lasting escape path from existential hazards in any of the cases listed above. Due to declining heat production inside their innards, such planets can no longer support oceans of liquid water (if such oceans exist).
Free-floating planets are similarly isolated and have less resources than planets that belong to a solar system. There are no asteroids to mine and no free solar energy, for example. In this realm, no seasons nor night and day exist. Plants, animals, and even bacteria do not exist. They serve just as a means to an aim.
“As a consequence, extraterrestrial civilizations would use free-floating planets as intergalactic transportation to reach and colonise other planetary systems, as opposed to using them as their permanent homes,” says Romanovskaya.
In her piece, Professor Romanovskaya speculates on possible outcomes. She envisions a civilization that achieves this feat several times, not to escape a dying star, but to fill the cosmos.
“In this manner, the parent civilization can spawn separate and independent daughter civilizations on different planets, moons, and space regions.”
She says, “A Cosmic Hitchhiker society would function as a ‘parent-civilization,’ disseminating the seeds of ‘daughter-civilizations’ in the form of its colonies throughout planetary systems.” Both living and nonliving organisms are harmed.
We have not yet worked out how to manage our planet’s temperature, and we are still in the beginning phases of protecting ourselves from catastrophic asteroid hits. As a result, the concept of utilising rogue planets to sustain humanity seems absurd. Nonetheless, Romanovskaya’s research focuses on detecting extraterrestrial civilizations and not on humans.
All of these actions might produce technosignatures and artefacts that reveal the existence of an ETC. The research report describes what they may be and how to identify them. If rogue planets are utilised as lifeboats, technological signatures like as electromagnetic emissions and other phenomena may be produced.
Solar sails may be employed by an ETC to manage a rogue planet or by a spacecraft launched from a rogue planet after it has reached its destination. Solar sails release cyclotron radiation, which is a technosignature, in every circumstance.
“… cyclotron radiation caused by the interaction of the interstellar medium with the magnetic sail” may come from deploying solar sails to steer a starship or an errant planet.
Infrared emissions may be another technosignature emitted as waste heat by an ETC on a hostile planet. An excessive amount of infrared or odd oscillations in the amount of infrared might be recognised as a technosignature.
The unequal distribution of infrared emissions throughout the planet’s surface may disclose underlying engineering or technology. A technosignature might also be a unique combination of electromagnetic radiation’s wavelengths.
Technosignatures could be detectable in the atmosphere, provided they exist. It may include evidence of terraforming, depending on the findings.
Astronomers do not know how many rogue planets exist or if they are currently concentrated in specific regions of the galaxy. In terms of determining these matters, we are just getting started. We may soon have a better understanding, though.
The Vera Rubin Observatory should be operational by 2023. This powerful observatory will photograph the whole visible sky in exquisite detail every few evenings. It has the largest digital camera in the world, with a CCD of 3,2 GB.
The Vera Rubin will excel at detecting transients, or changes in position or brightness over a few days. It will have a good chance of identifying any unwelcome guests, such as rogue planets, that approach our Solar System.
There’s a strong likelihood that some of these rogue planets may release peculiar emissions or exhibit peculiar behaviour. As was the case with Oumuamua, they will likely confound scientists.
A culture more advanced than ours may have previously faced an existential danger from a dying star. Perhaps they went to tremendous pains to capture and manipulate a rebel planet for their own reasons.
Perhaps they have already boarded it and sent it for a neighbouring, stable, long-lived yellow star with livable planets made of rock. Perhaps they are pondering whether or not their destination has life and how they will be received after their long journey.