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What if Earth had rings like Saturn? | Kids Crazy Thought Experiments · The Curious Kidcast | Fun Facts and Curious Questions

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  Imagine, just for a second, that you step outside, look up at the
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  sky, and instead of boring clouds and a bit of blue, you
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  see a gigantic glowing ring stretching from one side of the
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  horizon to the other. Like Saturn.
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  But it's Earth, our Earth. That is exactly what we are
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  talking about today. And I promise you, by the end of
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  this episode, you will never look at the sky the same way
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  again. Welcome to the Curious kid cast.
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  Curious kid cast, here we go. Questions.
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  Welcome, welcome. Welcome to The Curious Kid Cast,
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  the show where we take the biggest, brainiest, most
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  wonderfully strange questions in the universe and actually answer
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  them properly. I'm Charlie, your host, your
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  guide and yourself appointed Chief of Curiosity.
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  Today's question comes from a brilliant listener named Priya
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  from Brisbane in Australia, who sent in this absolute banger of
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  a question after her class did a project on the solar system.
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  Now Priya's teacher asked everyone to draw their favorite
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  planet. Most kids drew Earth.
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  A few drew Mars. One kid drew a planet that was,
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  according to Priya, just a wobbly purple circle with a face
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  on it, which is not technically a planet but gets full marks for
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  creativity. Priya drew Saturn because of the
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  rings. And then she sat back, looked at
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  her drawing, and had a thought so enormous it practically
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  echoed around the classroom. She asked what if Earth had
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  rings like Saturn and Priya? That is exactly the kind of
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  question this show exists for. Your teacher should give you
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  extra credit. Please forward this episode to
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  them as evidence. Let's start with the basics,
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  because before we go flying off into space, we should probably
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  understand what rings actually are.
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  Here is the thing that might completely surprise you.
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  Saturn's rings are not one big solid hula hoop floating around
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  the planet. I know, I know, that is what
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  most pictures make them look like.
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  But no, Saturn's rings are actually made of countless tiny
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  pieces of material all orbiting around the planet.
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  Some of those pieces are as small as a speck of dust, some
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  of the size of a Pebble. Some are as big as a house, some
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  are as big as an entire mountain, and they are mostly
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  made of water ice mixed with bits of rock and dust.
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  So imagine trillions of tiny icy chunks all zooming around Saturn
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  at the same time in an enormous spinning cosmic swarm.
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  It is less like a hula hoop and more like if you drop to 10
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  billion piece jigsaw puzzle in space and none of the pieces
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  could agree on where to go. Saturn is the most famous ringed
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  planet, but here is a fact that might knock your socks right
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  off. Jupiter, Uranus and Neptune all
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  have rings too. They are fainter, harder to see
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  and nowhere near as spectacular as Saturn's, but they are
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  definitely there. So rings are not some impossible
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  fantasy, they are real thing. Multiple planets have them.
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  Earth just currently does not. And we are going having to spend
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  this whole episode imagining that it does Earth.
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  Buckle up, you are getting a makeover.
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  So how would rings form in the 1st place?
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  Scientists think it can happen a few different ways.
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  Sometimes a moon drifts too close to a planet, and the
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  planet's gravity is so incredibly strong that it
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  basically rips the moon apart. That sounds horrifying.
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  If you are the moon, one minute you are a perfectly normal moon,
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  minding your own business doing moon things.
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  The next minute gravity has grabbed you by all sides and
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  torn you into a billion icy pieces.
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  There is actually a name for the distance since at which this
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  happens. It is called the Roche limit,
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  which sounds like the name of a very dramatic French chef, but
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  is actually the point where a planets gravity can overpower
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  the forces holding a large object together.
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  Cross that line and well, goodbye moon.
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  Hello rings. If Earth had rings, they would
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  probably have formed because something dramatic happened a
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  very long time ago. Maybe a small moon was
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  shattered. Maybe a huge asteroid broke
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  apart near us. However it happened, the result
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  would be an enormous number of objects orbiting Earth, all at
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  tremendous speed. And here is one of the most mind
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  bending science facts in the whole universe.
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  Those ring particles would be falling the entire time.
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  Constantly falling. But here is the trick.
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  They're also moving sideways so fast that they keep missing
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  earth. Think about throwing a ball.
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  It falls to the ground. Throw it harder, it goes farther
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  before landing. Throw it at an absolutely
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  impossible speed and it would fall around the earth rather
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  than into it. That is what satellites do.
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  That is what the moon does, and that is what ring particles
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  would be doing too. Eternally falling, eternally
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  missing. It is honestly one of the most
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  beautiful things about physics right now.
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  For the really exciting bit, what would you actually see if
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  you walked outside and Earth had rings?
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  If you were standing near the equator, you might see a
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  brilliant glowing arch stretching across the sky from
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  horizon to horizon, like someone painted a road through the
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  heavens. If you live further north or
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  South, the rings would appear at a different angle, like a
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  gleaming curved blade at the poles.
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  They might not be as visible at all, which is a bit unfair if
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  you are a Penguin, but that is just science.
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  The rings would reflect sunlight and could be absolutely dazzling
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  during the day. They might appear as a pale
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  glowing band. At sunset they could blaze
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  orange, pink and gold. At night they might make the sky
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  so much brighter that genuinely dark nights would become very
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  rare. In some places it would be
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  spectacular and also probably very convenient for anyone who
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  likes looking at stars through a telescope.
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  But here is where it gets interesting and a little bit
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  unexpected. All that extra light bouncing
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  around the sky would not just be pretty, it could mess with
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  nature in some serious ways. A huge number of animals depend
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  on darkness. Owls hunt in dim light, bats fly
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  at night, Sea turtles use moonlight and Starlight to
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  navigate when they hatch on beaches.
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  Nocturnal insects are attracted to light and if the nights
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  became brighter they could become confused, which would
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  then affect the birds and bats that eat them, which would then
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  affect the plants that need insects for pollination and so
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  on. Pull on one thread and the whole
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  jumper starts to unravel. Earths ecosystems are like that.
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  Complicated, connected and deeply unimpressed by giant
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  space rings changing the lighting.
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  Now here is something I did not expect when I first thought
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  about this. Rings could cast shadows onto
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  Earth. Actual shadows in space.
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  Think about that. A structure made of ice and rock
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  orbiting thousands of kilometers above your head could block
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  sunlight from reaching parts of the planet.
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  Depending on the season and the tilt of the rings, some regions
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  might spend part of the year under a faint band of shade that
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  could lower temperatures, change rainfall, shift wind patterns.
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  Scientists who study climate know that even small changes in
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  sunlight can have big effects. A giant ring system would not be
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  a small change, it would be enormous and nobody would be
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  able to agree on whose fault it was.
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  What about space travel? This is where things get
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  genuinely tricky right now. Getting a rocket into orbit is
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  already expensive, complicated, and takes a ridiculous amount of
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  engineering. Add a ring full of fast moving
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  icy debris between Earth and space and suddenly it becomes
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  extremely dangerous too. A tiny piece of ice moving at
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  orbital speed hits like an exploding cannonball.
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  Seriously, space agency. These already have to track
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  thousands of pieces of old junk in orbit around Earth, because
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  even a small bolt from a broken satellite could punch through a
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  spacecraft with rings. There would be far more stuff to
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  dodge. Astronauts might need specially
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  reinforced ships. Rockets might have to take very
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  specific paths through safe gaps in the ring.
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  Space tourism would probably have a much longer list of
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  warnings. Let's talk about ancient history
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  for a moment, because if Earth had always had rings, the whole
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  of human history would look completely different.
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  Ancient people would have seen those rings every day and built
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  enormous stories around them. Some cultures might have
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  believed the ring was a bridge to the heavens, a road used by
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  gods or spirits to travel between worlds.
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  Others might have thought it was a giant serpent curled around
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  the earth, or a Halo, or the boundary between the living
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  world and whatever comes next. Temples and monuments would
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  almost certainly have been built to align with it.
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  Just a Stonehenge aligns with the sun.
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  Imagine a whole ancient civilization whose entire
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  calendar, religion, and farming schedule was organized around
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  the rings. Their priests would probably
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  have been very smug about it. Sailors and explorers would have
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  used the rings for navigation the way they used the stars.
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  Calendars might have been based on the rings brightness at
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  different times of year. Scientists think the rings would
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  shift slightly in appearance as Earth goes around the sun,
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  sometimes looking wider, sometimes narrower.
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  Festivals would probably celebrate those changes.
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  There would be a ring festival with food, hopefully ring shaped
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  food. I would definitely go to ring
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  festival. Here is one of the most
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  astonishing facts about real rings and this one genuinely
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  shocked me. Saturns rings are unbelievably
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  wide, but also unbelievably thin.
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  They stretch out for hundreds of thousands of kilometers across,
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  but in many places they're only about 10 meters to 1 kilometer
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  thick. If you scaled Saturn's rings
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  down to the size of a sheet of paper, they would be incredibly
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  flat. So rings are not giant chunky
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  Halos. They are more like the thinnest,
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  widest cosmic pancakes you can possibly imagine.
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  And if you were somehow flying a spacecraft through the rings,
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  you might not see a wall of solid material.
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  You might see separate chunks spread out around you, each on
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  its own orbit. Still dangerous, still
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  beautiful, but not like flying into a rock face.
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  More like flying through a very large, very cold, very hazardous
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  snow globe. There is also something
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  fascinating called Ring rain, and it is exactly what it sounds
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  like. Tiny particles from Saturn's
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  rings are actually falling into Saturn's atmosphere right now.
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  Scientists discovered this not very long ago, and it was quite
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  a surprise. Material from the rings is
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  slowly raining down into the planet.
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  If Earth had rings, something similar might happen here.
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  Very small particles could drift down through the atmosphere.
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  Overtime, larger pieces could burn up as meteors.
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  Earth might experience far more frequent meteor showers than we
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  do today. Our skies could regularly be lit
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  up by streaks of burning material.
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  That would be brilliant, honestly.
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  Except for aeroplanes. Maybe they might have some
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  notes. Now here is a thought.
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  Earth with rings might actually be easier for aliens to spot.
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  Astronomers find distant planets by looking for them passing in
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  front of stars and blocking a tiny amount of light.
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  Rings would block extra light. A ringed Earth would produce a
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  slightly different signal. If there are intelligent beings
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  somewhere out there looking for planets, they might notice us
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  more easily if we had rings. Whether that is exciting or
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  slightly alarming is a matter of personal preference and also how
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  much science fiction you have watched.
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  Would life here be different? Absolutely.
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  Would it still exist? Almost certainly yes.
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  Humans are remarkably good at adapting to basically anything.
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  Put rings in the sky and within a few generations people would
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  just be used to it. Children born into that world
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  would think rings were completely normal.
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  They would grumble because the ring glare was making it hard to
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  see a meteor shower. They would moan about ring
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  shadow making their afternoon cold.
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  Parents would say things like in my day we were grateful for the
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  rings and kids would roll their eyes exactly as they do now.
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  All right, curious ones it is. Quiz time. 3 questions, a few
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  seconds to think and then the answers.
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  No peeking ahead, here we go question one.
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  What are Saturn's rings mostly made of?
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  Is it a solid gold, B water ice and rock, or C really old
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  cheese? The answer is B water ice and
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  rock. Saturn's rings are made mostly
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  of water ice mixed with bits of rock and dust.
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  Not gold unfortunately, and definitely not cheese, although
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  that would have made the ring rain much more interesting.
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  Question two, what is the special name for the distance
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  where a planets gravity can RIP a moon or large object apart?
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  Is it A the danger zone, B the rush limit, or C the smashy bit?
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  The answer is B the Roche limits.
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  That is the boundary where a planet's gravity overpowers the
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  forces holding a large object together.
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  Cross that line and things get very messy very quickly.
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  Question three Why are orbiting ring particles always falling
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  but never hitting Earth? Is it A because they are scared
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  of heights, B because they are moving sideways so fast they
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  keep missing the planet, or C because Earth politely asked
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  them not to? The answer is B they are moving
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  sideways at such incredible speed that even though gravity
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  is pulling them toward Earth, they keep flying past it.
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  They are in a constant state of falling and missing.
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  It is one of the most brilliant tricks in the whole universe,
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  and gravity came up with it entirely on its own.
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  And there you have it. If Earth had rings like Saturn,
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  our skies would be glowing, our nights would be brighter, our
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  animals would be confused, our space program would have a lot
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  more paperwork, and ancient civilizations would have built
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  some truly extraordinary temples.
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  It would be dangerous, dramatic, beautiful, and utterly
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  extraordinary. And the most amazing part is
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  that four other planets in our own solar system actually do
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  have rings right now. The universe decided Earth did
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  not need them. But there is absolutely nothing
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  stopping you from imagining otherwise.
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  Thank you so much for joining me on the Curious Kid cast today.
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  If you enjoyed this episode, please share it with a friend, a
• 13:30
  sibling, a parent, a teacher, or anyone who could do with a bit
• 13:34
  more curiosity in their day. Subscribe wherever you listen so
• 13:37
  you never miss an episode. And if you have a question you
• 13:39
  would like me to answer on the show, head over to
• 13:42
  curiouskidcast.com and send it in.
• 13:44
  It could be about space, animals, your body, the weather,
• 13:47
  why adults cry at adverts, anything at all.
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  We want to hear it. I'm Charlie.
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  This has been the Curious Kid cast.
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  Stay curious, keep asking questions.
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  And next time you look up at the sky, just take a moment to
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  imagine what it would look like with a giant glowing ring
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  stretched across it. Pretty good, right?