Long before the Sun swells into a red giant, the crisis would already have begun. As the star gradually brightens over the next billion years, Earth’s surface would become too hot for life. Yet instead of abandoning the planet, one new study argues that an extraordinarily advanced civilization might preserve Earth’s familiar skies, oceans, seasons, and even its geology through a coordinated system of planetary- and stellar-scale engineering designed to outlast not only the Sun itself, but nearly unimaginable spans of cosmic time.
For many discussions about humanity’s distant future, the assumption is simple: eventually, life must leave Earth.
The new paper explores a very different possibility. Rather than treating migration to another star as the inevitable solution, it asks whether Earth itself could remain home far beyond its natural lifetime if future civilizations became capable of engineering on scales that today exist only as theoretical concepts.
The investigation examines every major long-term natural threat identified by the author—from the Sun’s increasing brightness to the eventual shutdown of plate tectonics, the gradual escape of Earth’s water into space, the slowing of Earth’s rotation, asteroid impacts, nearby stellar explosions, and even encounters with passing stars. Instead of proposing a single grand machine, the paper develops an interconnected collection of safeguards intended to address each danger as it appears over billions, trillions, and eventually quadrillions of years.
The study concludes that, in principle, these combined systems could allow Earth to remain habitable for about 9.1 million billion years. If one additional concept—removing material from the Sun itself—were also implemented, that timespan could increase by roughly another order of magnitude.
The first threat arrives while the Sun is still healthy
Earth’s greatest long-term danger does not begin when the Sun dies.
According to the paper, the Sun has already spent roughly 4.58 billion years on the main sequence and continues to become gradually brighter as it converts hydrogen into helium. Around one billion years from now, that increasing luminosity is expected to move the habitable zone beyond Earth’s current orbit, making the planet unsuitable for surface life even though the Sun itself would still have billions of years remaining before becoming a red giant.
That creates the first engineering challenge: keeping Earth’s surface receiving essentially today’s level of sunlight despite the Sun’s changing output.
The paper explores two broad strategies.
One attempts to alter the Sun itself.
The other leaves the Sun alone while replacing its illumination.
Removing part of the Sun to slow its evolution
The first concept is known as star lifting.
The idea is to use a vast swarm of solar collectors orbiting close to the Sun. These structures would capture solar energy and direct it toward selected regions of the Sun’s surface, giving particles enough energy to escape the Sun’s gravity. By steadily removing mass from the Sun, the study argues, its internal evolution could be slowed.
Using stellar evolution simulations performed with the Modules for Experiments in Stellar Astrophysics (MESA) code, the paper modeled removing approximately 5 × 10¹⁹ kilograms of solar material every year until the hydrogen fraction in the Sun’s core reached a specified threshold.
Over roughly 5.1 billion years, that process would remove about 0.13 solar masses, equivalent to approximately 1.3 × 10²⁹ kilograms.
The simulations suggest that the Sun’s main-sequence lifetime would increase only modestly—from about 4.7 billion years remaining to roughly 5.1 billion years. The much larger effect appears elsewhere.
Without star lifting, the modeled Earth exits the habitable zone about 1.7 billion years from the present. With star lifting, the paper reports that Earth’s residence inside the habitable zone extends to roughly 9.2 billion years, well beyond the natural end of the Sun’s main sequence.
Blocking the Sun and building another one
The paper also investigates a more radical alternative.
Instead of modifying the Sun, an enormous sunshade positioned between Earth and the Sun would block incoming sunlight. A separate artificial light source would then provide Earth with carefully controlled illumination matching today’s conditions.
Scaling earlier concepts far beyond their original purpose, the study estimates that such a sunshade could eventually span hundreds of thousands of kilometers while being held in place using a tethered counterweight arrangement rather than relying solely on radiation pressure.
Because the Sun’s powerful red giant wind would exert enormous forces on the structure, the design includes an electromagnetic system intended to deflect much of the incoming solar wind around the shield. The paper also discusses material requirements, suggesting that extremely strong carbon-based materials such as carbyne could theoretically provide sufficient tensile strength for the supporting tether if manufactured at very large scales.
Recognizing that such a structure would become essential for Earth’s survival, the paper also considers redundancy.
If the primary shield failed, it proposes that a temporary sunshade stored on the Moon could be deployed while a permanent replacement moved into position.
Harvesting fuel from the giant planets
Blocking sunlight creates a second problem: Earth still needs energy.
Rather than obtaining that energy from the fading Sun, the paper proposes producing it inside the atmospheres of the giant planets.
Floating fusion-powered aerostats would collect hydrogen and helium from planets such as Jupiter, carry out nuclear fusion, and transmit the resulting energy through a chain of relay stations before converting it into artificial sunlight directed toward Earth.
The paper estimates that the gas giants collectively contain approximately 3.8 × 10²⁶ kilograms of suitable fusion fuel.
At Earth’s present solar energy requirement, the author calculates that this resource could provide about 9.1 × 10¹⁵ years of artificial sunlight—roughly 9.1 million billion years.
The study also considers an extension of this idea. Material previously removed from the Sun through star lifting could eventually be transferred to Jupiter, increasing the available fusion fuel and extending the potential sunlight supply to around 1.2 × 10¹⁷ years, or approximately 120 million billion years.
To maintain Earth’s familiar day-night cycle and seasons even after its own rotation gradually changes over cosmic timescales, the paper describes an orbital system of relay stations and artificial light sources designed to reproduce the changing pattern of natural sunlight.
Escaping the expanding red giant
Even if Earth’s temperature could be controlled, another problem would eventually emerge.
As the Sun becomes a red giant, its outer atmosphere expands enormously.
The paper’s stellar evolution models indicate that star lifting would reduce the Sun’s final mass while increasing Earth’s orbital distance enough to substantially lower the risk of engulfment. Even so, the author argues that relying solely on this effect would leave too little safety margin.
Instead, Earth itself should gradually be moved outward.
The proposed method adapts earlier work on orbital engineering but replaces occasional close flybys of massive objects with a continuous stream of much smaller particles.
According to the calculations, increasing Earth’s orbit from 1 astronomical unit to 1.2 astronomical units would require approximately 3.5 × 10³² joules of transferred orbital energy.
The study proposes obtaining oxygen from Jupiter’s deeper atmosphere, launching it toward Earth in carefully controlled particle beams, and using repeated gravitational flybys to slowly increase Earth’s orbital energy over roughly 100 million years.
The paper argues that replacing large individual flybys with continuous particle streams could avoid some of the tidal disturbances and catastrophic collision risks associated with previous concepts.
As Earth gradually moved farther from the Sun, the artificial sunlight system would compensate for the reduced natural solar energy reaching the planet.
Keeping Earth’s interior alive
The study argues that preserving Earth’s surface alone would not be enough.
Plate tectonics, driven by heat escaping from Earth’s interior, recycle essential elements, regulate the atmosphere, and continually reshape the planet’s surface. Yet the paper notes that Earth’s internal heat production is expected to decline enough for tectonic activity to cease in roughly 1.45 billion years.
The proposed solution is unusual even by the paper’s standards.
Instead of replacing radioactive heat sources inside Earth, the study suggests regularly delivering tiny quantities of antimatter deep into the planet.
Using a modified version of an earlier proposal for sending probes toward Earth’s core, the concept would inject frozen antihydrogen into the deep interior inside molten iron. Once the containment system naturally expired, matter-antimatter annihilation would release heat where it was needed.
The paper estimates that maintaining Earth’s present 47-terawatt internal heat output would require about 8.2 tonnes of antimatter each year.
To reduce seismic effects, multiple small injections rather than single large events would be staggered so that each individual release produced earthquakes too small to be noticed at Earth’s surface.
Replacing water faster than space can steal it
Even under controlled illumination, Earth would continue losing tiny amounts of water to space.
The paper estimates today’s escape rate at about 0.3 kilograms per second.
Although that loss is extremely slow, it accumulates over quadrillions of years.
To match the full lifetime of the proposed artificial sunlight system, the study calculates that Earth would need an average of roughly 1,000 tonnes of replacement water every year, eventually requiring a total equivalent to about 71 times Earth’s current water inventory.
Again, Jupiter provides the proposed solution.
Water or its constituent hydrogen and oxygen could be transported from the giant planet using the same large-scale infrastructure already developed for orbital engineering.
Preparing for dangers beyond the solar system
The paper’s timeline stretches so far into the future that hazards almost never discussed become relevant.
Nearby supernovae, gamma-ray bursts, and magnetar explosions could threaten Earth’s biosphere if sufficiently close. Drawing on previous proposals, the study discusses using swarms of particles or small objects held together electromagnetically as temporary radiation shields.
Passing stars present another challenge.
The paper notes that close stellar encounters become increasingly likely over billions of years and could destabilize planetary orbits, particularly during the future merger between the Milky Way and Andromeda galaxies.
Rather than moving Earth, the proposed response would slowly move the entire solar system.
Using material launched from Jupiter, a stellar engine could gradually alter the Sun’s motion through the galaxy, increasing the distance between the solar system and an approaching star before the encounter occurred.
Why stay instead of leaving?
Running throughout the paper is a broader question.
If technology eventually becomes capable of engineering entire stars and planets, why not simply migrate elsewhere?
The study argues that remaining on Earth could offer practical advantages.
Interstellar travel would require transporting people and a functioning biosphere across enormous distances, while also finding another planet capable of supporting long-term habitability. Space habitats and migration are both considered in the paper, but the author argues that maintaining Earth could be more feasible because most engineering would occur within the existing solar system using nearby resources.
The study also compares the energy requirements of different approaches. Although maintaining the safeguard system over billions of years requires far more total energy than a one-time migration, the paper argues that its required energy production rate would generally be much lower because the work would be spread over immense timescales. Many of the proposed engineering systems also rely on infrastructure—such as large-scale space mining—that the paper suggests could have independent economic value.
A conceptual blueprint for an almost unimaginably distant future
The paper does not claim these engineering systems are ready to build, nor does it argue that every technical challenge has been solved.
Instead, it presents a conceptual framework linking multiple speculative but theoretically grounded ideas into one coordinated long-term survival strategy.
The author acknowledges that future work would need to explore engineering details, long-term reliability, automation, maintenance over immense timescales, sociological questions, and additional natural threats that may not yet have been considered.
Taken together, however, the study offers a striking shift in perspective. Rather than viewing Earth’s habitability as ending when the Sun eventually changes, it imagines that sufficiently advanced civilizations might repeatedly intervene—shielding the planet from an aging star, replenishing its oceans, sustaining its geology, adjusting its orbit, and even redirecting the solar system itself—in an effort to preserve the same world for spans of time that extend into the farthest reaches of the universe’s future.
Publication details
Gabriel Harry, Retaining Earth’s Habitability Beyond the Life of the Sun, arXiv (2026). DOI: 10.48550/arxiv.2607.13084.
