When the Sun finally runs out of fuel, a cascade of dramatic things happen that will reshape our Solar System and test humanity’s ingenuity.

Things Happen as the Sun Enters Its Final Act

10 The Greenhouse Effect Will Become Extremely Effective

One of the earliest fireworks in this cosmic drama is the Sun’s brightness surge. As the star pumps out more energy, Earth soaks up extra heat. Our atmospheric blanket—carbon dioxide, methane, nitrous oxide—starts to trap that extra sunshine like a super‑insulated blanket, driving surface temperatures sky‑high.

Water everywhere begins to evaporate, forming a thick, reflective cloud that temporarily shields the planet. But the heat keeps climbing, eventually forcing the oceans to boil. Once the seas turn to steam, the planet becomes a barren furnace, and any remaining life would be doomed by scorching temperatures and a lack of water.

9 The Sun Will Expand

Next up, the Sun balloons into a red giant. After exhausting its hydrogen fuel, it ignites helium fusion, swelling dramatically while its surface cools to a relatively modest 2,000–3,000 °C—much cooler than its usual 5,000–9,000 °C skin.

Not every star follows this script. Tiny red dwarfs simply fade away, whereas massive blue or white giants forge heavier elements until an iron core triggers a spectacular supernova.

8 … And Then It Will Shrink

After the red‑giant phase, the Sun can no longer fuse helium into carbon, and it collapses into a white dwarf—a stellar ember about the size of Earth but incredibly dense.

White dwarfs glow faintly for billions of years before cooling into black dwarfs. The universe isn’t old enough for any black dwarf to have formed yet, so our Sun’s final ember will shine for an unimaginably long time.

7 Earth’s Orbit Will Change

As the Sun swells, its gravitational grip on nearby planets weakens. Earth, along with its siblings, will drift outward into a safer orbit, sparing it from immediate incineration—though any surviving life would already be long gone.

Mercury and Venus, however, will be engulfed by the expanding star, never getting the chance to escape.

6 Life May Form In Other Places

While Earth becomes a scorched wasteland, some of the outer moons could get a second chance. Jupiter’s icy moons—Europa and Ganymede—might warm enough under the red giant’s glow to melt their surfaces, potentially spawning subsurface oceans that could harbor life.

These moons already hide liquid water beneath their crusts, so a bit more solar warmth might tip the scales toward habitability.

5 Our Galaxy And The Andromeda Galaxy Will Merge

While the Sun’s drama unfolds, the Milky Way and Andromeda galaxies are on a collision course, racing toward each other at about 402,000 km/h. The two spirals will eventually merge, creating a new, larger galaxy.

Our solar system is expected to survive the galactic smash‑up, but the Sun will continue its own demise within this newly blended stellar neighborhood, offering future inhabitants a spectacular night sky.

4 The Outer Solar System Will Finally Feel The Heat

Beyond the inner planets, the distant reaches of the Solar System will finally get a taste of solar warmth. Pluto, currently chilling at –233 °C to –223 °C, will warm as the Sun’s envelope expands, turning icy worlds into slightly temperate relics.

Although the conditions still won’t be right for life, these outer bodies will retain a lingering glow from their once‑distant star.

3 Human Life Will Definitely Be Impossible On Earth

By the time the Sun reaches its final stages, Earth’s surface will be searing hot—far too extreme for any human to survive. Even advanced cooling tech couldn’t grow food or provide water under such conditions.

The internet, our cities, and every memory of our civilization will fade, leaving only the hope that life might later arise elsewhere, though likely very different from us.

2 Asteroids Won’t Make It Far

When the Sun finally settles into a white dwarf, its massive companion Jupiter will still dominate the system’s gravity. The giant’s tug will destabilize asteroid belts, flinging many rocky fragments out of the Solar System or pulverizing them into dust.

Observations of existing white dwarfs show dusty disks, evidence that former asteroids have been ground to fine particles around these stellar remnants.

1 Humans Could Find Another Way To Make It

Looking ahead, advanced technology might give humanity a lifeline. Spacecraft capable of reaching distant, potentially habitable worlds could allow us to escape the dying Sun.

Current efforts like NASA’s Mars missions hint at a future where colonizing other planets becomes reality. If we can master interplanetary travel, the Sun’s demise may become just another chapter in our cosmic adventure.

The Sun isn’t just a glowing ball of hot gas that keeps our days bright; it also hides a suite of menacing forces that keep scientists up at night. In this rundown of the 10 terrifying dangers our star can unleash, we’ll dive into everything from ultraviolet bombardment to the final fiery demise of the Sun itself, showing exactly why each hazard matters for life on Earth and beyond.

10. Terrifying Dangers of Our Sun

10. UV Radiation

Thanks to a thinning ozone shield, the Sun’s ultraviolet (UV) rays now reach the planet’s surface in larger, more hazardous doses. While a little UV helps our skin synthesize vitamin D, excess exposure is a serious health threat. It fuels skin‑cancer rates, speeds up premature aging, triggers cataracts, and can even suppress the immune system. Researchers have noted a disturbing rise in skin‑cancer incidence over the past three decades, a trend tied directly to ozone loss, and many fear the numbers will keep climbing if the protective layer continues to deteriorate.

9. Solar Flares

Solar flares are colossal bursts of electromagnetic radiation unleashed from the Sun’s surface when magnetic energy snaps and releases. Though a flare’s bright flash never reaches the ground, it can temporarily reshape Earth’s upper atmosphere, causing disturbances that ripple through GPS signals, satellite communications, and other high‑tech systems. NASA assures us that a flare won’t directly incinerate anything on the surface, but the resulting “mess” for our electronic infrastructure can be pricey and inconvenient.

8. Coronal Mass Ejections

Coronal mass ejections (CMEs) are massive eruptions that hurl billions of tons of plasma into space at millions of miles per hour. When a CME is hurled in Earth’s direction, it can slam into our magnetosphere, unleashing a torrent of charged particles. While the planet’s atmosphere shields us from direct harm, the resulting geomagnetic chaos can overload power grids, fry transformers, and knock satellites out of orbit. In our increasingly electronic world, a well‑aimed CME could cause widespread blackouts and costly satellite repairs.

7. Coronal Holes

Coronal holes appear as dark, cooler patches on the Sun’s surface, especially near solar minimum, and are regions where magnetic field lines open outward. These openings let fast solar wind stream directly into space. When Earth runs into this wind, we can experience several days of heightened geomagnetic storms, which, while not lethal to humans, can damage satellites, disrupt global communications, and pose serious radiation risks to astronauts. The spectacular Aurora Borealis and Aurora Australis are beautiful side‑effects of these solar wind encounters.

6. Geomagnetic Storms

The 1859 Carrington Event – a “mega‑flare” that sparked a worldwide geomagnetic storm – painted the skies from Honolulu to Chile with auroras and sent telegraph operators scrambling as sparks leapt from their equipment, sometimes igniting fires. Modern society, heavily dependent on electricity and satellite tech, would be far more vulnerable. A storm of comparable magnitude today could cripple power grids, knock out GPS, and render satellites inoperable for years. Scientists warn that such a solar megastorm is not a matter of “if,” but “when.”

5. The Sun Makes Interplanetary Travel A Lot More Dangerous

Beyond Earth, the Sun’s radiation becomes a formidable foe for any would‑be interplanetary explorer. While our planet’s magnetosphere offers a protective bubble, astronauts venturing to Mars or beyond face a relentless mix of galactic cosmic rays and intense solar particles. These high‑energy rays can damage DNA, increase cancer risk, and impair mission hardware. Researchers are racing to devise shielding technologies, but the clock is ticking: if humanity must eventually flee a dying Earth, we need robust radiation protection sooner rather than later.

4. The Sun Will Eventually Evaporate The Earth’s Water Supply

Our Sun, now a middle‑aged main‑sequence star, quietly brightens about ten percent every billion years. That gradual surge pushes the habitable zone outward, meaning Earth will receive ever‑greater solar flux. Eventually, this extra heat will push surface temperatures high enough to turn oceans into vapor, essentially “boiling away” the planet’s liquid water reservoir. Though the Sun still has billions of years left, this slow but relentless warming spells a bleak future for terrestrial life.

3. The Oceans Will Boil

As solar luminosity climbs, oceans will not simply disappear; they will enter a runaway greenhouse phase. More heat drives more water into the atmosphere, thickening it with steam—a potent greenhouse gas that traps even more heat. This feedback loop accelerates until the seas reach boiling temperatures, evaporating into a super‑heated vapor envelope. The planet’s surface would dry out, leaving a barren, scorching world with a sky of scorching steam.

2. The Sun Will ‘Bleed’ The Water From Our Atmosphere

Even after the oceans have boiled away, a lingering veil of water vapor will cling to Earth’s atmosphere. As the Sun expands into a red giant, its intense radiation will split water molecules, allowing hydrogen to escape into space while oxygen may linger or recombine. In effect, the Sun will “bleed” the planet dry, stripping away the last vestiges of water and leaving a desiccated world devoid of the essential ingredient for life as we know it.

1. Scientists Disagree On How Long It Will Take, But The Sun Will Eventually Die

Astrophysicists agree on the Sun’s ultimate fate, but they differ on the timeline. Some models predict Earth will become a scorched, lifeless rock within a billion years as the Sun swells into a red giant, while other scenarios allow pockets of life to persist a bit longer. In the red‑giant phase, the Sun will balloon dramatically, engulfing the inner planets or at least scorching Earth’s surface beyond repair. Even if Earth drifts outward as the Sun sheds mass, it will be left as an unrecognizable, barren husk.

Eventually, the Sun will shed its outer layers, leaving behind a dense white dwarf that will cool over billions of years before fading into a cold, dark planetary nebula. This final chapter is projected to unfold over roughly ten billion years, a span far exceeding humanity’s likely existence. In short, the Sun’s death is inevitable, and the clock is ticking.

Ready for a solar adventure? Here are 10 stellar facts about NASA’s Parker Solar Probe, the bold spacecraft that’s set to literally touch the Sun. From a half‑century of planning to breaking speed records, this mission packs more excitement than a fireworks show on a solar flare.

10. Stellar Facts About NASA’s Sun Mission

10. Goal To ‘Touch The Sun’

The Parker Solar Probe is on a quest no other human‑made object has ever attempted: it will plunge into the Sun’s outer atmosphere, or corona, and collect data right where the action is. NASA’s official tagline captures the drama: “This summer, humanity embarks on its first mission to touch the Sun.”

Beyond the headline‑grabbing goal, the probe is designed to unravel the Sun’s secrets and show how solar activity shapes Earth’s magnetic environment—knowledge that’s becoming ever more crucial as our technology gets increasingly vulnerable to solar storms.

This historic plunge will answer long‑standing questions while inevitably sparking fresh mysteries for the next generation of solar scientists.

9. 50-Year Effort

The August 2018 launch capped more than five decades of theory, debate, and engineering. Scientists first sensed the corona’s million‑degree heat in the 1940s and confirmed the existence of the solar wind in the 1960s, yet the mechanisms behind these phenomena remained elusive.

It wasn’t until 1958 that someone proposed actually measuring the corona up close. Over the ensuing years, several spacecraft flirted with the Sun, but none ventured close enough to satisfy Parker’s vision. Budget cuts and shifting priorities shelved many earlier concepts, pushing the ultimate effort back repeatedly.

Now, after half a century of groundwork, the Parker Solar Probe finally brings those early ideas to fruition.

8. First Spacecraft Named After A Living Person

NASA has traditionally christened probes after planets, mythic deities, or even fictional characters, but never after a living individual—until now.

Eugene Parker, born in 1927, is a towering figure in astrophysics, boasting honors such as the National Medal of Science, the Royal Astronomical Society’s Gold Medal, and the Kyoto Prize. His pioneering work on solar wind and the coronal heating problem reshaped our understanding of how stars behave.

In a rare move, NASA named the mission after Parker before launch, making the Parker Solar Probe the first spacecraft to bear the name of a living person as it heads beyond Earth’s orbit.

7. Solar Wind

Solar wind is the mission’s beating heart. Originating in the Sun’s corona, this stream of charged particles can zip through space at speeds up to 1.6 million km/h (about 1 million mph).

Because the corona’s extreme heat weakens the Sun’s grip on its own particles, the wind escapes into the solar system, eventually reaching Earth where it can wreak havoc on satellites and power grids.

By sampling the wind right at its source, scientists hope to decode how the corona heats up and why the solar wind accelerates, turning a cosmic mystery into a tangible set of data.

6. The Sun Is Really Hard To Get To

Getting to the Sun is no walk in the park—its energy demands are roughly 55 times greater than a typical Mars transfer. Though the Sun sits 150 million km (93 million mi) away, the true challenge isn’t distance but the need to cancel out Earth’s sideways orbital motion.

Our planet rockets around the Sun at about 108,000 km/h (67,000 mph). A spacecraft launched directly toward the Sun would inherit this sideways velocity and miss the target entirely. The solution? Launch the probe “backward” at a speed that cancels Earth’s forward motion.

Even after solving the navigation puzzle, the probe still has to survive the blistering environment of the outer corona, a feat made possible by its cutting‑edge heat shield.

5. Gravity Assists From Venus

To shed its sideways speed gradually, the Parker Solar Probe takes advantage of Venus’s gravitational pull. Each close flyby of the planet acts like a cosmic brake, pulling the spacecraft into a tighter orbit around the Sun.

Over the mission’s seven‑year span, the probe will perform seven such Venus fly‑bys, each one shaving away enough orbital momentum to let it dive ever closer to the star.

This intricate dance dictates a narrow launch window—a two‑hour daily slot that repeats for about two weeks each summer when Earth and Venus line up just right.

4. Fastest Man‑Made Object In History

Thanks to the Venus assists, the Parker Solar Probe will eventually blaze through space at a jaw‑dropping 692,000 km/h (430,000 mph)—the fastest speed ever achieved by a human‑made object.

For perspective, NASA’s Juno spacecraft tops out at 266,000 km/h (165,000 mph), while Voyager 1 cruises at about 61,000 km/h (38,000 mph). Parker’s velocity is more than twice Juno’s and eleven times Voyager 1’s.

On Earth, that means the probe could zip from Philadelphia to Washington, D.C., in just one second.

3. Heat Shield

The probe’s heat shield is a marvel of engineering. Measuring 2.4 m (8 ft) across, it sits at the front of the spacecraft, deflecting the Sun’s ferocious heat away from delicate instruments.

It consists of a 11.4 cm‑thick (4.5 in) block of carbon foam sandwiched between carbon‑carbon composite panels, together weighing just 73 kg (160 lb). While the corona’s temperature reaches 1.1–1.7 million °C (2–3 million °F), the shield’s design lets the probe survive by exploiting the sparse distribution of plasma particles.

Lead engineer Betsy Congdon likens it to briefly touching a blazing oven: “Those are very hot, but we’re not touching a lot of them.” The shield enables the probe to survive the Sun’s outer layers without melting.

2. Most Autonomous Spacecraft Ever

Because the Sun‑Earth communication lag is about eight minutes, the probe must act on its own in mere seconds when conditions change. Highly automated software lets it make rapid, real‑time adjustments without waiting for ground control.

The onboard computer is pre‑loaded with every plausible scenario scientists could imagine, allowing the heat shield to rotate, the spacecraft’s orientation to shift, and other critical maneuvers to happen autonomously.

Project scientist Nicola Fox of Johns Hopkins’ Applied Physics Laboratory calls the Parker Solar Probe “the most autonomous spacecraft that has ever flown.”

1. Unique Cargo

While the probe can’t carry heavy payloads, it does transport a very human cargo: the names of more than 1.1 million people who signed up for a virtual seat aboard the mission.

In March 2018, NASA invited the public to submit their names for a memory card on the spacecraft. Iconic actor William Shatner, famed for his role as Captain Kirk, helped promote the campaign, leading to a flood of submissions.“It’s fitting that as the mission undertakes one of the most extreme journeys of exploration ever tackled by a human‑made object, the spacecraft will also carry along the names of so many people who are cheering it on its way,” said project scientist Nicola Fox.

Kurt Manwaring is a syndicated freelance writer at fromthedesk.org.

What happens when the star that lights our days finally runs out of steam? Nothing in the cosmos is permanent – not the chilly November drizzle, not the continents we stroll across, and certainly not the brilliant ball of plasma that keeps us warm. One day the Sun will exhaust its fuel and, in true apocalyptic fashion, the universe will feel the tremors. Fortunately, that finale isn’t penciled in for any near‑future calendar, so you can relax and enjoy the sunshine while you still can.

1 Can The Sun’s End Be Stopped?

So, let’s imagine humanity still hanging around a billion years from now. The Sun keeps getting hotter, the light gets brighter, and clever engineers start asking: can we pull the plug on this cosmic death‑watch? The 2007 sci‑fi flick Sunshine dramatized exactly that scenario – a crew of astronauts flying out to the Sun with a gigantic nuclear bomb, hoping to reignite its dying core. In reality, such a stunt sounds like pure Hollywood, yet we have a whole eon to invent technologies far beyond today’s imagination.

Scientists have tossed around a handful of wild ideas for taming a star on the brink. One proposal suggests we could vent the excess helium that builds up in the Sun’s core – roughly one to five million tons per second – to ease the pressure and keep fusion humming longer. Another concept involves “stirring” the Sun, mixing fresh hydrogen from the outer layers into the core, a bit like shaking a pot of soup so the ingredients blend better. Both tactics would demand engineering feats that dwarf anything we’ve ever attempted, and each carries its own set of risks.

A more exotic notion envisions using massive, space‑based lasers to carve away hydrogen from the Sun’s outer shell, effectively splintering the massive ball of gas into several smaller red dwarfs. Those mini‑suns would burn cooler and slower, extending the overall lifetime of the system. Yet, redirecting that much energy into a star could backfire spectacularly, igniting violent flares or destabilizing the core.

Injecting fresh hydrogen straight into the heart of the Sun is another speculative route. While it sounds like a straightforward refuel, the sudden influx could trigger uncontrolled eruptions, sending the star into a frenzy of solar storms. In short, any attempt to rescue the Sun would be a high‑stakes gamble, and we have a whole billion years to figure out if it’s even possible.

2 Can Earth Survive?

Predicting the exact look of our Sun when it transitions from a yellow dwarf to a red giant is tricky, but computer models give us a fairly grim picture. In roughly five billion years, the swelling star is expected to engulf Mercury, Venus, and, depending on how the expansion unfolds, possibly Earth itself.

If you’re planning a career that stretches into the far future, you might want to consider a contingency plan for the planet’s demise. In a few hundred million to a billion years, the Earth will likely become inhospitable as the Sun’s output climbs. Estimates suggest we have about 500 million years before surface oceans evaporate and the planet turns into a scorching, Venus‑like world.

The Sun’s luminosity has already risen about 30 % since its birth, and it continues to climb at roughly 10 % per billion years. This gradual brightening will eventually lower atmospheric CO₂ to levels that can’t sustain complex plant life, effectively ending the majority of Earth’s biosphere.

Some optimistic researchers argue that the CO₂ feedback loop may not be as temperature‑driven as once thought, granting plants an extra 600 million years before they succumb. After that, a “moist greenhouse transition” – a runaway increase in atmospheric water vapor – could seal Earth’s fate, heating the planet beyond the point where life can survive.

Regardless of the exact timeline, the atmosphere will eventually be stripped away by the Sun’s relentless heat, leaving a barren, carbon‑dioxide‑rich world reminiscent of Venus. Whether Earth is fully swallowed or merely scorched to the point where only its iron core remains, the outcome is the same: no life as we know it.

Interestingly, the outer reaches of the solar system might briefly become habitable. Bodies like Pluto could find themselves in a temperate zone, potentially harboring liquid water for a short window. Yet, the window is so fleeting that the chances of life taking hold are slim.

Bottom line: the Sun’s death spell spells the end for Earth, no matter how clever we get. There’s no scenario where our home planet outlives its star.

3 Could the Sun Become a Black Hole?

Massive stars that end their lives in spectacular explosions can collapse into black holes, regions of spacetime where gravity is so strong that even light cannot escape. Those behemoths typically start out eight to ten times the mass of our Sun before they go supernova and shrink into singularities.

Our Sun, however, is a modest yellow dwarf – far too lightweight to undergo such a dramatic finale. It lacks the mass needed to trigger a supernova, and consequently, it will never become a black hole or even a neutron star. Its destiny is a quieter one: a slow fade into a white dwarf after shedding its outer layers.

4 What Happens Next?

When the Sun finally swells into a red giant and then contracts, it will shed a considerable portion of its mass, leaving behind a dense, cooling core known as a white dwarf. At this stage, nuclear fusion ceases entirely; the star becomes a slowly dimming ember drifting through space.

Recent computer simulations suggest that, rather than simply cooling, the Sun will also expel roughly half of its remaining mass into the surrounding vacuum, creating a spectacular planetary nebula. This glowing shell of gas and dust will be illuminated by the hot core, producing a brief but breathtaking display that may only persist for about 10,000 years in cosmic terms.

If you’ve ever admired photos of nebulae, that’s the kind of spectacle our Sun will produce in its swan song – a radiant cloud of stellar remnants surrounding a faint, white dwarf core, a fleeting masterpiece before the star fades into obscurity.

5 How Will the Sun Die Out?

In roughly four to five billion years, the Sun will have burned through virtually all of its core hydrogen, leaving only helium behind. Because the core can’t generate the temperatures needed to fuse helium efficiently, the star’s energy production will start to falter.

Gravity will then dominate, squeezing the core tighter while the outer layers, still rich in hydrogen, ignite in a shell around the helium core. This shell‑burning causes the Sun to balloon outward, transforming the once‑steady yellow dwarf into a massive red giant that could stretch all the way to Mars’s orbit.

The core, now essentially dead, will be compressed to extreme densities, while the hydrogen burning in the surrounding shell fuels the dramatic expansion. As the red giant phase peaks, the Sun’s radius will increase dramatically, and its outer atmosphere will become tenuous, setting the stage for the eventual shedding of its outer layers.

Eventually, the Sun will lose enough mass that its grip on the remaining planets weakens, and the star will settle into a compact, hot white dwarf, cooling slowly over billions of years. This final state marks the official death of our stellar neighbor.

6 When Will it Happen?

The Sun is composed of roughly 92 % hydrogen, which fuels a relentless chain‑reaction in its core. At a blistering 27 million °F, the core pressure forces hydrogen atoms to fuse into helium, releasing immense energy that bathes our planet in light and warmth.

Our star’s mass is about 330,000 times that of Earth, a figure so massive that it’s often expressed as “four point four followed by thirty zeroes” in pounds. Though astronomers can measure it precisely, the sheer scale is mind‑boggling.

When the Sun finally exhausts its hydrogen supply – an event projected to occur in roughly five billion years – it will not die immediately. At that point, the star will still have two to three billion more years of dramatic evolution before it reaches its ultimate goodbye.

Currently classified as a yellow dwarf or G‑type main‑sequence star, the Sun will, as its hydrogen dwindles, transition into a red giant before eventually shedding its outer layers and leaving behind a white dwarf. This multi‑stage process will shape the fate of the entire solar system.