Even at the speed of light, traveling to the nearest star system would take more than four years.
Needless to say, escaping a solar system is much easier said than done. But according to a new paper published in the International Journal of Astrobiology and spotted by Universe Today, an advanced civilization could do exactly that — by using an entire planet as a giant spacecraft.
In other words, a rogue planet, according to Houston Community College professor Irina Romanovskaya, could operate as a lifeboat, allowing a civilization to leave its old host star behind.
“I propose that extraterrestrial civilizations may use free-floating planets as interstellar transportation to reach, explore, and colonize planetary systems,” wrote Romanovskaya.
Nature may have already done so inadvertently by launching rogue planets with habitable subsurface oceans into the galaxy. Astronomers have long suspected the existence of a region enveloping our solar system known as the Oort Cloud, which is thought to be home to tiny, icy planets.
If we commandeered such a world, Romanovskaya proposes, it could provide everything needed to survive the long journey.
“Free-floating planets can provide constant surface gravity, large amounts of space and resources,” she argued. “Free-floating planets with surface and subsurface oceans can provide water as a consumable resource and for protection from space radiation.”
If such a planet is uninhabitable or excessively dark, intelligent civilizations may have already created technologies such as fusion reactors to make it habitable.
Romanovskaya suggests that “cosmic hitchhikers” could one day exploit things like Sedna, a dwarf planet in our distant solar system with an eccentric orbit, as a route of escape.
One potential issue with taking a ride on a rogue planet is that its core may run out of heat and “eventually fail to support oceans of liquid water (assuming such oceans exist),” according to Romanovskaya.
They’d also be quite remote from any other resources essential to a civilization’s survival.
“Therefore, instead of making free-floating planets their permanent homes, extraterrestrial civilizations would use the free-floating planets as interstellar transportation to reach and colonize other planetary systems,” Romanovskaya concludes.
The hypothesis also raises the exciting potential that SETI researchers could focus on detecting any aliens using a planet as a mode of transportation.
“I propose possible technosignatures and artifacts that may be produced by extraterrestrial civilizations using free-floating planets for interstellar migration and interstellar colonization, as well as strategies for the search for their technosignatures and artifacts,” Romanovskaya wrote.
That implies we might be able to catch a glimpse of a civilization during its great escape — and perhaps learn a thing or two in case the Sun threatens the Earth in the distant future by transforming into a deadly red giant.