Chapter 1: The Future of Earth in a Changing Cosmos

In previous articles titled “When Jupiter Becomes a Star” and “When Earth Has 12 Suns,” we delved into the concept of rescuing our planet from the inevitable doom posed by an aging sun. As our sun transitions into a red giant, its outer layers will extend to reach Venus, leaving Earth to face scorching temperatures and eventual disintegration. We examined the difficulties involved in altering Earth’s orbit and converting Jupiter into a stellar body to supply additional energy. Furthermore, we discussed the challenges of extending the sun's lifespan and creating new stars from extracted materials.

These challenges call for creativity, bravery, and unwavering resolve. Yet, they seem far less daunting compared to the proposal we’ll discuss today: the complete replacement of our sun with a younger star. This intriguing concept is referred to as “solar exchange.”

While this idea may sound unconventional and intricate, it is surprisingly one of the simplest and most feasible solutions we have encountered thus far. Solar exchange could be the key to preserving our beloved planet.

The notion of solar exchange was introduced by astronomer J. G. Hills in 1984. Hills conducted extensive research and published numerous papers on stellar simulations. In one of his simulations, he created a model featuring a sun-like star with a single orbiting planet. He then introduced a second star of similar size and discovered that if the approaching star came within 2-3 times the radius of the planet's orbit, the original star-planet system's trajectory could either be expanded or disrupted. There was also a possibility that the new star could capture the planet, resulting in it orbiting this new stellar host.

Hills theorized that a sufficiently advanced civilization could orchestrate such a stellar interaction, allowing a younger star to capture Earth in a stable orbit with an acceptable level of eccentricity (a measure of how elongated an orbit is, typically ranging from 0 to 1). Currently, the planets in our Solar System have an eccentricity of less than 0.2. By carefully timing this encounter, we could minimize significant disruptions from neighboring planets.

This entire process could occur millions of years before our sun is destined to become a red giant, thereby averting catastrophe and safeguarding our planet. During this time, we could identify the most suitable replacement star and plot a trajectory that ensures minimal complications due to planetary alignments. This period would also allow us to develop the necessary technology to transport a star across the vast distances of interstellar space.

Stars naturally pass by our Solar System at speeds around 19 miles per second (30 km/s), meaning that if we took approximately a million years to execute this solar exchange, a typical star could traverse about 100 light-years in that timeframe. There are estimated to be around 12,000 stars within 100 light-years, with 300 of them being similar in size to our sun, many of which would be considerably younger, offering billions of years of stability around our new stellar neighbor.

Now, we must address the core scientific question: how can we propel a star situated 100 light-years away onto a collision course with our Solar System?

A potential solution lies in adapting a rocket propulsion system, similar to the Star Lifting method discussed in a prior article. This approach would involve using a ring of ion accelerators to create a magnetic field around the star, allowing for mass to be ejected from designated poles. If we assume a star possesses a magnetic field, ejecting mass from one of these poles would generate the necessary propulsion to set the star on its new trajectory.

To minimize the aging of the star, we should aim to extract as little mass as possible. The exhaust velocity of this new star would be approximately 385 m/s (620 km/s), and the total mass required for propulsion would be quite small, estimated between 0.002 and 0.032. The entire process could take anywhere from 1 to 10 million years.

The visual spectacle would be remarkable: first, a faint point appearing in the night sky, gradually becoming brighter as it navigates its way through our Solar System until it arrives within one astronomical unit of the sun. The night sky would transform, temporarily hosting two brilliant giants vying for control over Earth’s orbit. This would lead to extreme tides, earthquakes, and natural disasters that would make current climate change challenges seem trivial. We would need to endure this chaotic transition for about a year until we finally stabilize in a new orbit.

Although this maneuver appears straightforward, it has yet to be addressed that we will need to develop spacecraft capable of interstellar travel and implement a magnetic field around our chosen star. The interstellar travel challenge is one that future generations will hopefully resolve long before this scenario unfolds. As noted in the first part of this article series, humanity may no longer exist by the time the sun becomes a red giant. We could evolve into a successful interstellar civilization that has moved on to new frontiers, but Earth may still hold value for us—whether for sentimental reasons, scientific inquiry, or as a remnant of life’s beginnings.

It’s conceivable that an advanced civilization somewhere in the universe is currently grappling with this very dilemma, facing the increasing heat from their aging star. They, too, may need to seek out a younger, more stable star to bring into their system. The challenges they face today could very well mirror those we may confront tomorrow. At some point, we might have to bid farewell to our beloved sun—the one that nurtured us, inspired our creativity, and bore witness to our existence. Letting go will be a profound act of mourning, coupled with the hope of securing a brighter future for our planet.

Chapter 2: The Cosmic Journey Begins

In the first video, titled "A Star Passed By Our Solar System and Altered Its Orbit 56 Million Years Ago," we learn about historical cosmic events that have influenced our solar system's structure and stability.

The second video, "JWST Discovers NEW PLANET - It's the Coldest, Oldest Exoplanet Ever Imaged," showcases the latest discoveries in exoplanet research, emphasizing the ongoing exploration of potential new worlds.