Stellar Engines: How to Move the Solar System and Escape a Supernova

If humanity manages to become a Type 2 Civilization, we will have solved all the problems that affect us today… but inevitably we will find others. The galaxy, the entire universe is in motion, and with a bit of bad luck, there are events that would wipe us off the map, including a nearby supernova or a gamma ray burst. However, there is a resource that could help us escape that fate: the stellar engine. If our Solar System is in danger, why not move it elsewhere…?

Once again, the explanation of the stellar engine comes through the Kurzgesagt channel, which taught us concepts like the Skyhook for placing material in orbit, the "emergence" or why stupid things separately become intelligent together, and the Great Filter, a viable theory against the apparent lack of life in the universe.

The idea of the stellar engine responds to an external threat, but it is not necessary to think on scales like a wandering black hole. The simple "visit" of another star or a substellar object (for example, a brown dwarf) could completely wipe out life on Earth… unless we get out of its way. The first advantage is that as a species we would have a lot of time to prepare, so something impossible "today" would only be "very difficult" for a Type 2 Civilization. The second is that we do not need to move every object in the Solar System. If we move the Sun, everything tied to its gravity will follow.

Shkadov Thruster

The simplest of the stellar engines is the so-called Shkadov Thruster, equivalent to a mirror or solar sail placed in a fixed position over one of the Sun's poles (otherwise, we run the risk of frying or freezing planets). The parabolic shape makes the reflected solar radiation (about 50 percent) generate thrust and slowly move the Sun. The Shkadov thruster limits our movement options, but they should be enough to escape in most cases.

Caplan Thruster

Now, what happens if "no" is not enough? Is it possible to escape faster? Kurzgesagt presents a variant called the Caplan Thruster, which combines a super-space station with a Dyson sphere or ring to extract solar material, and thus power a fusion reactor, which fires a stream of particles at 1 percent of the speed of light, while a second thruster pushes the Sun, almost like a tugboat.

The thruster consumes millions of tons of material per second, but our star would not be affected (in fact, its life would be longer), and its efficiency is such that it could move the entire system up to 50 light years in a million years.