Jupiter.
Uranus.
Saturn.
Earth?
Sadly, the Earth didn't make it onto the list
of the Solar System's ringed planets.
This is WHAT IF,
and here's what would happen
if the Earth had rings like Saturn.
When the Earth was young,
it most likely had a ring
of rock debris around it.
4.5 billion years ago another
planet, Theia, hit the Earth.
The giant impact sent a ring of matter
hurtling into the Earth's orbit.
But it didn't stay like that for long.
The rocky debris soon formed
another celestial body -
the one we now call the Moon.
Having planetary rings visible in the sky
would look way more spectacular
than just one grey rock, right?
Maybe.
But if our planet got beautiful
rings like these tomorrow,
much of life on Earth might not
survive the renovation process.
It wouldn't necessarily take another collision
to form rings around the Earth.
We could just crumble the Moon.
And for that, we'd only need
to move it a little closer.
The gravitational pull that our
planet exerts on the Moon
isn't equal everywhere.
It's much stronger on the side
of the Moon that is closest to us.
There is a limit on how close
celestial bodies can be to each other.
It's called the Roche limit.
If they get any closer than that limit,
the larger body shreds the
smaller one into pieces.
The distance of the Roche
Limit depends on the size,
mass and density of the two objects.
For instance, the Sun rips
up comets that comets
within 1.3 million km (0.8 million mi) of it.
The Earth will tear apart
an average-sized comet
from approximately 18,000 km
(11,185 mi) away.
For the Moon, the Roche limit
would be 9,500 km (5,900 mi).
The rings we might get from
something the size of the Moon
would be about 5,000 km (3,100 mi) wide
and around 9.5 m (31 ft) thick.
But unlike Saturn's icy rings,
ours would be made of nothing but rock.
The Earth is just too close to the
Sun to keep the debris iced.
Looking out at the sky,
you'd be able to see these
rings from Earth at all times.
Because of the brightness of the rings,
the Moon wouldn't seem as bright anymore.
That is if we still had the Moon.
If the Moon crumbled up
and became our rings,
there'd be nothing else up there to look at.
And there would be some
other consequences.
The rings suddenly hugging Earth
would disrupt internal navigation
systems of some animals.
If not enough direct sunlight was
making it through the rings,
they would also affect photosynthesis
and our oxygen supply.
In the shadow of the rings, with
no contact from the Sun’s rays,
the temperature would get so cold
that it would make the shadowed areas
of the Earth almost uninhabitable.
Communications satellites, generally
placed around the Earth's equator,
would find themselves right
in the middle of a rock storm.
We'd need to find another
way to keep the internet alive
if we want to keep posting
selfies on a ringed Earth.
We'd be better off in a scenario
where the Earth has always been like this.
Provided we didn't lose sunlight and oxygen,
we'd evolve just fine.
But we'd have to develop
other means of communication
since we wouldn't be able to send
satellites into an orbit full of rocks.
Space would never become our final frontier.
The rocky rings around the planet
would be a sort of orbital barbed wire fence
keeping us all grounded.
And, just like the rings of Saturn,
Earth's rings wouldn't last forever.
One day they'd start to feel their
age and drop from the sky.
Make sure to wear a helmet,
and don't forget to look up and enjoy the show.
If the multiverse is real,
there might be a ringed
Earth somewhere out there,
with people on it wondering
what it would be like to live
on a planet with no rings.
But we'll leave that story for another WHAT IF.
