The inevitable death of our planet Earth is tied to the life cycle of our sun and the unforgiving march of cosmic time. Here’s a comprehensive timeline:
5–7 Billion Years from Now
- The Sun Becomes a Red Giant:
- Our sun will exhaust its hydrogen and helium reserves, leading to a dramatic expansion. It will grow to 256 times its current size, engulfing parts of the inner solar system.
- Mercury and Venus Are Consumed:
- The expanding red giant will sweep through the inner solar system, swallowing Mercury and Venus. Earth’s proximity will bring extreme heat, making life increasingly unsustainable.
5 Million Years After the Sun Turns Red Giant
- Carbon Dioxide Depletion:
- Extreme heat will halt carbon cycling, effectively ending photosynthesis. Plants—the primary oxygen producers—will perish.
- Massive Oxygen Drop:
- With no plants to replenish oxygen, mammals and birds will suffocate. Oxygen-dependent species will rapidly die off, leaving behind only creatures that require minimal oxygen.
- Insect Extinction:
- As the ecosystem collapses, insects—the most populous creatures—will succumb, followed by microbial life. Tardigrades, with their unparalleled resilience, will be the last surviving organisms.
As Temperatures Escalate
- Global Devastation:
- Rising temperatures exceeding 2,400 K (2,130°C or 3,860°F) will incite violent storms, rain, and wind, damaging the planet irreparably.
- Earth Loses Its Atmosphere:
- The planet’s atmosphere will erode due to the sun’s radiation. The surface will transform into a barren wasteland of metal and metal oxides.
- Lava Oceans Form:
- As Earth boils, its oceans will completely evaporate, leaving a massive sea of molten lava. With no water to lubricate tectonic plates, geological activity will cease.
7.6 Billion Years from Now
- Earth and Moon Are Swallowed:
- The red giant’s expansion will likely engulf Earth and the moon, erasing any trace of their existence.
- New Habitable Zone Forms:
- As the sun’s habitable zone moves outward into the Kuiper Belt, icy celestial bodies like Neptune’s moon Triton and dwarf planet Eris will thaw, creating potential new habitats for future human colonies.
1 Quadrillion Years Later
- The Sun Becomes a Black Dwarf:
- After billions of years as a white dwarf, our sun will cool into a black dwarf, a cold, dense remnant about the size of Earth. By then, it will no longer emit heat or light, leaving the solar system a dark and desolate space.
What Happens Beyond?
- As Earth meets its fiery end, humanity’s survival will depend on our ability to colonize new worlds. Liquid water may become available in the outer solar system, opening opportunities for life on Triton, Eris, or other distant icy worlds.
This timeline of Earth’s demise serves as both a stark reminder of cosmic impermanence and a call for innovation, urging humanity to look toward the stars for its future survival.