The Sun’s core is shrinking. But as its core shrinks, the Sun itself grows larger. And it will continue to grow, until one day, it engulfs the Earth. How long can you survive?
What will happen to the oceans? Will other planets be affected?
Every one billion years, the Sun becomes 10% hotter. But here on What If, we’re going to take billions of years and condense the action into one month. Get ready, because we’re going to be moving really fast this time.
Instead of 1 billion years, it would only take four days for the Sun to become 10% hotter. This means you’ll see the Earth engulfed by the Sun in just one month. That is, if you’re still around to witness the final event.
On day one, you’d be blissfully unaware of the tragedy about to befall Earth. Maybe it’s a little hotter, but that’s just weather. It happens. But by day four, space agencies across the globe would be sounding the alarm bells.
By this time, the Sun would be about 10% brighter and hotter. And while 10% doesn’t sound like a lot, it will be the beginning of the end for us. As the Sun heat ups, more and more water from Earth’s surface will evaporate into the atmosphere.
This will increase the greenhouse gas effect, causing global temperatures to skyrocket. All of a sudden, it will become very humid, and very hot. But the Sun’s high-energy light would bombard the atmosphere, splitting those water molecules into hydrogen and oxygen.
Earth will begin to lose its water. And you won’t be able to escape the lethal radiation on Earth’s surface. If you want to survive, you’ll have to go deep underground. But even under a protective layer of Earth’s soil, you won’t be safe for long.
By day 16, the Sun would be almost 40% brighter. Our planet’s oceans will boil, and there won’t be any moisture left in the atmosphere.
The beautiful, lush Earth that you grew up on will become a hot, dry, barren rock. Around day 20, the Sun would run out of hydrogen. So instead, it will start to burn helium in its core.
The Sun is now a red giant star, and would expand rapidly while losing its mass. The Sun’s gravitational pull on Earth would be weakened, and our planet would begin to drift away from the expanding Sun.
But not far enough. According to researchers Klaus-Peter Shroder and Robert C. Smith, the Earth will only have moved about 0.0002 Astronomical Units. An Astronomical Unit is the distance between Earth and Sun.
While Earth is moving away from the encroaching Sun, the red giant would grow up to 1.2 AU in radius. The Sun would be larger than Earth’s orbit. It would swallow the planet whole.
Once it’s inside the Sun’s atmosphere, Earth would collide with particles of gas and spiral inward. And Earth wouldn’t be the only casualty of the expanding Sun. Mercury and Venus would be vaporized.
The rings of Saturn would melt. Pluto would become much warmer. And if there is a liquid surface, and a thick atmosphere on this distant dwarf planet, it even might become inhabitable. Unfortunately, 30 days doesn’t give the human race enough time to prepare for such a catastrophic event.
- “The Sun Will Eventually Engulf Earth–Maybe”. Appell, David. 2008. Scientific American.
- “The sun will destroy Earth a lot sooner than you might think”. Ali Sundermier. 2018. The Independent.
- “Red Giant Stars: Facts, Definition & The Future Of The Sun”. Redd, Nola. 2018. space.com.
- “Will Earth survive when the sun becomes a red giant?”. Matt Williams 2020. phys.org.
- “Here’s What Happens To The Solar System When The Sun Dies”. Eric, Betz. 2020. Discover Magazine.