Scientists have discovered many planets
similar to Earth beyond our Solar System.
These exoplanets can be
up to 10 times larger than Earth,
which might be ideal for our growing population.
But with more mass comes more gravity,
and despite having more space for life,
we'd be heavily affected
in many ways on a Super Earth.
What would happen
if we evolved on a bigger planet?
Imagine growing up on
a Neptune-like exoplanet
7.5 times the mass of our Earth.
This Super Earth is located in
orbiting a red dwarf star at a safe distance.
One year on GJ 180 d lasts a mere 106 days,
less than one-third of a year on Earth.
Your summers may be
a little shorter on GJ 180 d,
but a week's vacation would stretch
a whole lot further than it would on Earth.
To live on a Super Earth
would require super strength.
If Earth were 10 times larger,
gravity would be 10 times stronger.
This is based on the formula of
A short jog on a Super Earth
would feel like running a marathon!
The stress on our muscles and bones
would increase by a factor of 10.
At the very least,
you could cut down on your reps
when you workout.
Technically, our skeletons can withstand a force
of more than 90 times that of the Earth's gravity,
but only when standing still.
With much more force pulling us down,
our organs would shift
and we'd likely develop
some serious health issues,
and an unavoidable paunch.
Maybe a little Super Earth yoga might help!
Our atmosphere here on Earth
is held together by gravity.
At sea level, atmospheric pressure
is around one atmospheric unit.
But at higher altitudes,
like the peak of Mount Everest,
the pressure is much lower,
approximately 0.33 atmospheric units,
because it is further from the Earth's core.
We don't notice this pressure very much,
but the air we breathe
would feel much heavier on a Super Earth.
Just as air pressure changes with gravity,
our water would also be affected.
With more air pressure,
water would take longer to boil and freeze.
This is because it would require more energy
for water molecules to evaporate
or solidify into a heavier atmosphere.
Prepare to wait a lot longer
for your instant noodles.
Although we might be able to survive
in these heavier conditions,
the gravity of this Super Earth situation
is much more dangerous than you might think.
Earth's gravity
helps keep our magnetic field intact.
The movement of liquid iron in our outer core
generates this magnetic field,
which protects us from harmful solar radiation.
On a Super Earth,
higher gravitational pressure
might cause a solid inner core.
No liquid movement of iron
would mean no magnetic shield,
and we'd be at risk of severe radiation exposure.
We may need to wear protective suits
or build sheltered walkways just to be outside.
And this solar radiation
could knock out any power grids,
meaning we'd have to find
new ways of transferring electricity.
And with a drastically weakened ozone layer,
our risk of getting certain
environmental cancers would seriously increase.
But that isn't even the biggest problem.
With a greater gravitational pull,
we'd be attracting more
unwanted objects from space.
The likelihood of meteors and asteroids
striking us would be much higher.
Take Jupiter, for example.
With 2.5 times Earth's gravity,
it gets hit up to 60 times a year
by objects ranging anywhere from 5 to 20 m (16 to 65 ft) in diameter.
In 2009, it was struck by a whopping 500 m (1,650 ft) asteroid.
The size of a giant asteroid hitting a Super Earth
would be important, but also,
where might it land?
Sixty-six million years ago, an asteroid
collided with Earth in a carbon-rich area,
causing organic material in rocks to be heated
and ejected into the atmosphere,
forming soot in the stratosphere.
This triggered drastic climate cooling
which led to the mass extinction of dinosaurs.
As a result, mammals evolved.
If this asteroid had landed somewhere else,
maybe there could still be dinosaurs
roaming around today.
A similar global annihilation
is very probable on a Super Earth.
For humans to survive and evolve
on a planet like this,
we would have to be very lucky.
So, what if we needed to leave this Super Earth
to avoid a disaster?
Our space program would need
a much bigger budget.
More gravity to contend with
would mean a lot more fuel to get anywhere.
For a rocket carrying a payload
of over 40,000 kg (88,000 lbs),
similar to the one used
on the Apollo moon mission,
the fuel required would cause the rocket
to weigh over 360,000,000 kg (794,000,000 lbs).
This would be like trying to launch
the Empire State Building.
One Polish mathematician suggested another solution,
For this, an unmanned probe carrying dozens
to several hundred nuclear bombs
would fly alongside a rocket.
Detonating these bombs at close intervals
would help push the rocket upward.
This is pretty risky though,
especially if the probe misfires in our direction.
To put it simply, if we lived on a Super Earth,
we might be stuck there for a while.
We'd probably be better off
just exploring space with telescopes
from the Super Earth's surface.
If you want to dive deeper
into what life might be like for the human race
on a Super Earth,
check out our What If Discussed episode
on this exact topic.
We sat down with astrophysicist
Jack Madden of Cornell University,
who filled us in on all the details
of exoplanets and Super Earths.