If Earth is destroyed, will we be able to migrate to another planet?

About 5 billion years from now, the Sun will leave the main sequence and become a red giant. It will expand and turn into a glowing ball, destroying everything around it including Mercury, Venus, Earth and Mars. So can humanity survive the red giant phase of the Sun? Can we survive by migrating to another star system without using spacecraft?

Humans in general and astrophysicists are already well aware of the difficulties of interstellar travel. Our nearest solar system is Alpha Centauri. If humanity had to flee an existential threat in the Solar System, locate a new home in Alpha Centauri, it would take us more than 4 years traveling at the speed of light to reach this place.

Currently, it takes humans about 5 years to send an orbiter to Jupiter at our technological level. There is a lot of debate surrounding transgenerational spacecraft, where humans can live for generations while en route to a distant habitable planet. Those ships don't need to get anywhere at the speed of light or equivalent. Instead, generations of humans on it will be born and die on a journey to another star, which will last hundreds or thousands of years.

Will we be able to escape our "house" that is about to perish?

So is there any other way that we, or some other civilization, can escape our "house" that is about to perish? The authors of a new research paper in the International Journal of Astrobiology say that ETCs (extraterrestrial civilizations) may not need transgenerational ships to escape these threats.

Instead, they could use free-floating planets as a means of transportation. Irina Romanovskaya, Professor of Physics and Astronomy at Houston Community College, thinks that extraterrestrial civilizations could use free-floating planets as means of interstellar travel. explore and colonize planetary systems. When it comes to finding other civilizations, these efforts can leave behind technosignatures or artifacts.

It is possible that the planets roaming the Milky Way, or some of the hundreds of billions of other galaxies, carried their own life in subsurface oceans kept warm by radioactive decay. Then, if they encountered a star and were gravitationally bound, that life effectively used a floating planet to transport itself to hopefully somewhere "hospitable." " than. So why can't a civilization like us imitate that?

We might think of free-floating planets as dark, cold, and inhospitable ones. They probably wouldn't, unless they had warm subsurface oceans. Although harsh, it still brings certain advantages. Free-floating planets can provide constant surface gravity, large amounts of space and resources. Free-floating planets with surface and subsurface oceans can provide water as a consumable resource and for protection from space radiation.

ETCs can use free-floating planets for transportation.

An advanced civilization could also engineer the planet to an even greater advantage by manipulating it and developing energy resources. Romanovskaya suggests that, as we are on the verge of using controlled fusion, advanced civilizations may already be using it, which could change a cold, evil planet into a something that can support life.

The author outlines four scenarios where the ETC could take advantage of these floating planets:

- The first scenario involves a floating planet that happens to be passing through the home world of an ETC

How often that can happen will be tied to the overall number of floating planets. So far, astronomical studies have not pinpointed how many, but they certainly exist. In 2021, a team of researchers announced the discovery of between 70 and 170 rogue planets, each about the size of Jupiter, in one region of the Milky Way. And by 2020, a study suggests there could be as many as 50 billion planets floating in our galaxy. So where do they come from? Most of these planets were likely ejected from their solar system by gravitational events, but some may have formed through star-like accretion.

Another source of floating planets is the Oort Cloud of the Solar System. If another system had a similar cloud of objects, they could be a rich source of stellar stellar activity.

Stars with masses between 1-7 solar masses undergoing post-main sequence evolution, as well as a supernova from a 7–20 solar-mass precursor, can propel ovoid cloud objects out of their system so that the objects become unbound to their host stars. But how long can an ETC, or Earth civilization, expect a floating planet to get close enough to hitch a ride? A 2015 study found that the binary W0720 (Scholz's star) passed through our Solar System's Oort Cloud about 70,000 years ago.

Although it is a star rather than a planet, it shows that the objects have passed relatively close. If studies predicting billions of wandering planets are correct, some of them may have passed near the Oort Cloud long before we had the means to detect them. The Oort Cloud is a long way from coming, but a sufficiently advanced civilization might be able to see an approaching rogue planet and go out and meet it.

- The second scenario involves using technology to steer a wandering planet closer to the home of a civilization

With the advancement of science and technology, they can select an object from their own Oort Cloud and use propulsion to direct it towards a safe orbit near their planet. With enough preparation time, they can tailor the subject to their needs, for example, by building underground shelters and other infrastructure. Maybe, with the right technologies, they will change or create a new atmosphere.

- The third scenario is almost identical to the second scenario, involving an object from the outer Solar System of civilization

Romanovskaya uses the dwarf planet Sedna in our Solar System as an example. Sedna has a very eccentric orbit, taking it from 76 AU from the Sun to 937 AU in about 11,000 years. With enough technology and lead time, an object like Sedna could be turned into a ship for us to escape. The study authors note that the civilizations capable of doing such things would be advanced civilizations that have had their planetary systems explored at a distance of at least 60 AU from other planets. host star.

There are many potential problems here, such that sending a dwarf planet from the far reaches of the Solar System into the Solar System could disrupt the orbits of other planets, leading to all sorts of dangers. lurking danger. But the dangers would be minimized if a civilization around a post-main sequence star had migrated out with the changing habitable zone. Discussions on the required energy source and the time required for migration were also conducted.

- The fourth scenario also involves the same subjects as Sedna

As a star leaves the main sequence and expands, there is a critical distance at which objects will be ejected from the system instead of remaining gravitationally bound to the dying star. If an ETC can pinpoint when these objects will be ejected from the rogue planet, they can prepare in advance and get it out of the dying Solar System. That can be extremely dangerous, however, as periods of intense mass loss from the star pose a huge danger.

As can be seen in all of these situations above, the wandering planets or other object will not be a permanent home but will be a lifeboat. Nor do these planets serve as means of escape from existential threats. These floating planets are also isolated and have fewer resources than planets in the Solar system. For example, there are no asteroids to mine and no free solar energy, no days and nights or seasons, no flora, fauna and even bacteria. They are simply a means to an end. So, the researchers say, instead of making free-floating planets permanent homes,

Roaming planets or other objects can be "lifeboats" for humanity.

Professor Romanovskaya also speculates that if a civilization does it again and again, it's not to escape a dying star but to spread across the galaxy and its colony. In this way, the parent civilization can create unique and autonomous child civilizations inhabiting different planets, moons, or regions of space. A civilization of "Hitchhikers" in the universe will act as a "parent civilization" to spread the seeds of child civilizations in the form of its colonies in planetary systems. .

Humanity is only in the early stages of protecting itself from catastrophic asteroid impacts, and we are not yet able to manage our planet's climate with any degree of stability. So, the thought of using floating asteroids to keep humanity alive may seem far-fetched, but the above studies seem not to be about us but other civilizational discoveries. .

All of this activity can generate technical signals as well as artifacts indicating the presence of ETC. Roaming planets used as lifeboats can produce specifications such as electromagnetic emissions or other phenomena. An ETC can use Solar sails to steer a free-floating planet or use them on a spacecraft launched from a roving planet once they have reached their destination, In either case, Solar sails produce one specification: cyclotron radiation.

Maneuvering a spacecraft or floating planet with a solar sail generates cyclotron radiation due to the interaction of the interstellar medium with the magnetic sail. Infrared emission could be another technological feature that is emitted as waste heat by an ETC on a planet. It is possible to detect multiple infrared rays or unnatural changes in the amount of infrared rays as a signal technique. Infrared rays can be emitted unevenly across the planet's surface showing the underlying technique or technology. An unusual mixing of different wavelengths of electromagnetic energy can also be a signal engineering. The atmosphere itself, if it exists, may also contain these features, which, depending on what is observed, may contain evidence of topography.

Another civilization more advanced than ours faced an existential threat from their dying star.

Currently, astronomers do not know how many planets are floating or whether they are concentrated in certain areas of the galaxy. We are at the starting line when it comes to figuring these things out, but perhaps there will be better ideas soon.

The Vera Rubin Observatory will see its first light in 2023. This powerful observatory will image the entire available sky every few nights, and it will do so in detail. It houses the largest digital camera ever produced. Vera Rubin works particularly well at detecting anything that changes position or brightness over the course of a few days. It would have a good chance of detecting any invaders such as rogue planets that could approach our Solar System.

There is also a very high probability that some of those floating planets will exhibit some unusual and puzzling features, questions that may be answered by science as it did with Oumuamua. It is speculated that another civilization more advanced than ours has faced an existential threat from their dying star. And they made a Herculean attempt to take over a wandering planet in order to design it to suit their needs. They stepped on it and launched it toward some distant, stable, star that could last longer. And maybe they are wondering if there is life at their destination and how they can be received after the long journey.