It's a small world after all,
because today,
we're shrinking Earth to the size of Pluto.
But if our planet was this tiny,
Pluto sits on the Solar System's edge,
just beyond Neptune's orbit.
It was once considered a planet.
But then in 2006
scientists demoted this celestial body
to a dwarf planet.
All because Pluto
isn't big enough to gravitationally dominate in its own orbit.
After all, this dwarf planet
is only two-thirds the diameter of our Moon.
So if Earth was as tiny as Pluto,
how would eight billion people fit on it?
Say goodbye to your personal elbow room.
We would have to fit everyone
into an area
slightly bigger than Russia,
71% of which would be covered with oceans.
But the good news is this shrunken Earth
would still have room for everyone.
Just barely.
You and every person on the planet
would have about 1.5 tennis courts to yourselves.
The problem is that doesn't take into account
the space we still need for hospitals,
airports and roads.
Once we build those,
things would start getting cramped.
Add to that all the uninhabitable areas like deserts and mountains,
and you won't have enough room to comfortably fit everyone.
But if you're looking for a quick escape,
it would be easy for you to make a break for it.
One jump could catapult you almost 7.6 m (25 ft) into the air.
And that leap would last for almost 10 seconds,
giving you a spectacular view of the horizon.
You could also run faster
since there would be less friction.
But, watch out for slick surfaces.
They could send you flying long distances
because there wouldn't be enough gravity
to keep you in place.
Refrain from over-exerting yourself with all this running.
On this dwarf planet,
the air pressure would also be small.
So no matter where you're at,
it would feel like standing on a mountaintop 5,000 m (16,404 ft) high.
Yeah, with less oxygen to breathe,
you would be constantly gasping for air.
If you're lucky,
this high-altitude sickness will leave you light-headed.
But, if you're unlucky, it could kill you.
But even that wouldn't be the worst-case scenario
if the Milky Way always had a mini-Earth.
Technically, the lack of gravity would make Earth uninhabitable.
A study out of Harvard from 2019
found that a planet needs a mass
of at least 2.7% of the Earth to keep water on the surface.
If Earth had formed to be the size of Pluto 4.5 billion years ago,
it would never have its mighty oceans.
Now, how would this affect the Moon?
Well, Pluto's largest moon,
Charon, doesn't orbit the dwarf planet.
Instead, the two bodies are tidally locked with the same sides,
always facing each other.
Our dwarf Earth
would be forever facing the Moon in the same position,
locked in place by a common center of mass
caused by our competing
gravitational pulls.
But all of this
would be the least of our problems.
If Earth was this small,
its inner core would be much cooler.
Now, that might sound good at first.
Earthquakes would stop
because there wouldn't be shifting tectonic plates anymore.
Volcanoes would become harmless mountains.
But unfortunately,
Earth wouldn't have a protective magnetic field
without the hot molten core.
With this gone,
the radiation from the Sun
would fry our planet.
Now, what if Earth wasn't formed to be the size of Pluto?
What if instead it suddenly shrunk?
Well, then our planet would keep its mass.
But that would make the surface gravity
30 times stronger than what it is now.
With intense training,
the human body can survive on a planet with four times the Earth's gravity.
But a planet with 10 times the gravity of Earth?
That would break your bones.
If you weighed 75 kg (165 lb) before,
now you would weigh around 2,300 kg (5,000 lb).
Every move you make
would take serious muscle power
and you may not have it in you,
no matter how hard you try.
An instantaneous dwarf Earth
would cause mass devastation.
It could destroy everything we love about this planet
and leave humanity hanging on for dear life.
Now, maybe we would have a better chance
if the planet was larger.
What if Earth was the size of Jupiter?
Well, keep watching,
because that's a story for another WHAT IF.