What does Earth sound like from space?


Space is a desolate void, a vacuum where no
sound can travel. So you might think that space is extremely
quiet. You would be right, but only because you don’t
have the capability to hear anything with your natural ears. Turn your ears into radio wave receivers,
and suddenly space is a constant symphony of strange and interesting sounds. (space sounds) I’m Alex McColgan, and you’re watching
Astrum, and together we will find out what the sources of these radio waves are, and
what they sound like! We don’t have to go too high above Earth
to already be in space, only 160km up and sound can’t be heard anymore because there
aren’t enough particles for sound waves to travel. But even here in space, there are plenty of
other waves to be found. The ones particularly interesting to us are
electromagnetic waves, which don’t require other particles to travel
like sound, but rather travel by themselves through photons. You are witnessing a form of electromagnetic
radiation right now in the form of visible light by watching this video. However, visible light is just a tiny section
of the total spectrum of electromagnetic radiation. It stretches from gamma waves, waves with an
extremely high frequencies, to radio waves, with waves sometimes kilometres long. There are observatories that look at all the
different wavelengths, and this channel has focused normally on frequencies higher than
infrared as they can be easily converted and visualised in visible light. But there are also even radio observatories,
some orbiting Earth right now. And we are going to check out what they have
picked up in the way you are most used to witnessing radio waves: at audio frequencies
converted to sound. Being in the Earth’s Van Allen belt,
or its large band of radiation surrounding the planet, and you’ll already start hearing
some very interesting sounds. (space sounds) These sounds are generated by energetic particles
in Earth’s plasmasphere, which are being tugged to and fro by the rotation of Earth’s
magnetic field. You see, there is a plasmasphere around Earth,
containing clumps of ions and electrons. As Earth and its magnetosphere rotate, the
magnet fields push through these particles, accelerating them is a wave called a plasma
wave, similar in a way to how disturbances in the Earth’s oceans can cause waves to
form. You are hearing these disturbances in the
form of radio waves as they pass by one of NASA’s Van Allen probes. These are called chorus waves, and are often
heard during Earth’s dawn which is why they are found on this side of the planet. (space sounds) An amazing type of chorus wave closer to Earth
is the whistler-mode plasma wave, which sounds like space battles and laser fire. (space sounds) These exist in the cold and denser part of
the plasmasphere, and are caused by electromagnetic radiation released by lightning strikes in
the atmosphere. The waves generated by these strikes can bounce
around within the magnetic field of the Earth, and because higher frequencies travel faster
than lower frequencies, that is why these chorus waves sound like they have a falling
pitch, like a whistle! (space sounds) Going further out from the plasmasphere, an
opposite effect can be heard. (space sounds) This time, there is a rising tone, almost
like a conversation between songbirds. It is thought to be caused by electrons moving
towards the night side of Earth because of magnetic reconnection in Earth’s magnetotail,
transferring their energy to the plasma as they collide with it, as can be seen in this
simulation. In another region within the plasmasphere,
we can find something called hiss waves. (space sounds) These are thought to be chorus waves that
have leaked out from the inner plasmasphere. It sounds much more menacing and cold than
the other sounds we have heard so far. I really find these sound clips very interesting
as it’s sometimes hard to comprehend waves you can’t see, but sound adds a new layer
of understanding when combining it with a visualisation. Even with this though, electromagnetic radiation
can be a difficult subject to grasp. Brilliant.org has a course specifically on
radiation to help fill in the knowledge gaps, where they explain about the electromagnetic
spectrum and how it travels in waves. So much of our day-to-day life is governed
by these waves, from seeing with our eyes, to the wifi we receive on our phones, to the
radio stations we tune in to. Give Brilliant a go for free today and gain
a better understanding of the world around you! By using the link brilliant.org/Astrum, you
can have a sample of their courses, plus if you opt for the annual premium subscription,
the first 200 people will get 20% off. And so there we have the sounds of radio waves
in space around Earth! If you liked what you saw and heard today,
why not join my other Patreons in supporting the channel? You can donate to have your name added to
this list! All the best, and see you next time.

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