How much water would you need
to extinguish the Sun?
Whatever your plan is, be careful.
Because trying to put out the Sun
would only make it hotter.
Before we dive into how things
would go terribly wrong,
let's talk about where we could,
hypothetically, find all that water.
I've got some ideas.
How about the Universe’s largest ice cube?
A gigantic space firehose?
Or an entire waterworld tossed into the Sun?
Okay, fine.
Let's be a little more realistic.
No giant ice cube will be passing our Solar System
anytime soon.
That leaves us with one possible scenario.
We'd have to sacrifice every single drop of water
we have here on Earth.
We would drain our oceans
and deplete all of the freshwater, too.
Then we'd build a very large firehose
and blast it at light speed towards the Sun's core.
And then...
Did I say there was just one option?
I forgot about the possibility of using a waterworld.
Leaving the Earth with no Sun and no water
seems a bit unreasonable.
And we could avoid that ocean-draining scenario
if we found a way to throw an exoplanet into the Sun.
But not just any exoplanet.
We'd be aiming for a real-life waterworld.
And we just happen to know where to find it.
Some 40 light-years from Earth,
there is a planet primarily made of water
with an atmosphere of steam.
Scientists named it GJ 1214b.
But we'll call it the waterworld.
This planet is 2.7 times bigger than the Earth in diameter,
and it weighs seven times more than our planet.
And it has much less rock
and a lot more water than the Earth does.
There would probably be enough water on the waterworld
to put out the Sun forever.
But it wouldn't happen the way you might expect it to.
If we were able to crash that waterworld into the Sun,
the first problem would be the water freezing in space.
Same thing would happen
if we could pull out a gigantic firehose
with all of Earth's water and aim it at our star.
The ice would continue shooting towards the Sun,
but it would face mass-evaporation
as soon as it hit the star's atmosphere.
The water vapor would then break down
to its basic ingredients, oxygen and hydrogen.
And that's when something interesting would happen.
The Sun may seem like a huge fireball, but...
it's not exactly on fire.
Inside its blazing core,
the pressure is 340 billion times more
than it is on Earth's surface.
This immense pressure fuses hydrogen atoms together,
making helium and giving off energy in the process.
Since hydrogen acts like fuel for our Sun,
pouring water on it would be like throwing gasoline on a fire.
You'd see the Sun turn bluish white
as it grew six times bigger.
It would create an extreme heat wave across our planet.
But at least we wouldn't be engulfed
by the expanding Sun,
although there could be other consequences.
We wouldn't be able to put out the Sun with its own fuel.
But if we fired enough water at it
at the speed of light,
it could break up the Sun.
The pressure inside it would drop.
The hydrogen couldn't fuse together into helium.
And that would shut the Sun down.
With no Sun to give us warmth and light,
the Earth would turn into a frozen world.
After just one year, Earth's temperature
would drop below -73°C (-100°F).
Most of the plants and animals
would be dead long before that.
In the deepest parts of the oceans,
geothermal vents could have kept us warm
and supplied us with energy.
But we just poured all of Earth's water into the Sun,
dooming ourselves to freeze.
Lucky for us, the only thing in the Universe
that can do any substantial harm to the Sun
is the Sun itself.
And that would take billions of years to happen.
But that's a story for another WHAT IF.