{"id":29848,"date":"2022-03-08T09:57:25","date_gmt":"2022-03-08T09:57:25","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=105401"},"modified":"2022-03-08T10:21:17","modified_gmt":"2022-03-08T10:21:17","slug":"is-there-sound-in-space","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/is-there-sound-in-space\/","title":{"rendered":"Is there sound in space?"},"content":{"rendered":"

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By Dave Hawksett\n \t\t<\/p>

Published: Tuesday, 08 March 2022 at 12:00 am<\/p>

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Astronomy is all about light. Of course, when we say \u2018light\u2019, we mean the complete span of the electromagnetic spectrum, of which only a tiny proportion is visible to the naked eye.<\/p>\n

But astronomy can also be about sound. As we all know, sound waves are different to light waves.<\/p>\n

Light waves can pass through many media, depending on their wavelength and the medium\u2019s properties.<\/p>\n

Light waves don\u2019t actually require a material to travel through, and so the light from stars is unhindered by the vacuum of space.<\/p>\n

For more on astronomical audio, read our guide on how astronomers listen to the sound of stars<\/a>.<\/strong><\/em><\/p>\n

\""What\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Credit: Eric Lowenbach \/ Getty Images<\/span><\/figcaption><\/div>\n

Sound waves, however, involve the compression and rarefaction of matter.<\/p>\n

The vibration of the surface of a drum, for example, also makes the air molecules vibrate.<\/p>\n

These in turn cause adjacent air molecules to vibrate and so a sound wave travels outward from the drum.<\/p>\n

In a vacuum, there are no molecules in contact with the surface of a struck drum, so a microphone next to it will pick up absolutely nothing, no matter how hard the drum is banged.<\/span><\/p>\n

So how do astronomers hear any sound at all in space?<\/span><\/p>\n

They do it using a technique called sonification, where data is converted into sound to allow it to be interpreted.<\/span><\/p>\n

The humble Geiger counter is an excellent example of this, measuring radiation levels and portraying the results as audio.<\/span><\/p>\n

Just as X-ray data from space is often turned into coloured images, various astronomical data can be usefully \u2018sonified\u2019.<\/span><\/p>\n

Can sounds travel through space?<\/b><\/h2>\n
\""The\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
The dynamo effect of the Earth\u2019s spinning molten core produces our planet\u2019s magnetic field, which prevents the solar wind from stripping away our atmosphere. Credit: Naeblys \/ Getty Images<\/span><\/figcaption><\/div>\n

Are there actually sounds in space? If so, how can they be heard, and how do astronomers know they\u2019re there?<\/p>\n

Space is not a perfect vacuum: the stream of charged particles flowing from the Sun \u2013 the solar wind \u2013 pervades the Solar System with an extremely thin gas in which various ethereal phenomena occur.<\/span><\/p>\n

Unlike the gas in our atmosphere, which is bound together by the mutual collisions of air molecules, this plasma is bound together by the magnetic field surrounding it. <\/span><\/p>\n

The turbulent nature of the Sun\u2019s surface means that pressure and density disturbances travel outwards at the speed of sound in the solar wind.<\/p>\n

Due to the temperature and density of the plasma, this is around a few hundred kilometres per second.<\/p>\n

These pressure disturbances are effectively sound waves in interplanetary space.<\/p>\n

The thin plasma of the solar wind, along with the solar magnetic field<\/a> that binds it, becomes weaker and even more sparse as you travel outwards into the depths of the Solar System.<\/p>\n

Eventually it becomes so weak that it is overwhelmed by the combined magnetic fields and particles from all the other stars in the Galaxy.<\/p>\n

This zone, known as the \u2018heliopause\u2019, marks the end of the Sun\u2019s dominion and is the true edge of the Solar System<\/a>.<\/p>\n

Below we\u2019ve taken a look at some bodies of the Universe capable of making sound, and how astronomers are able to hear them.<\/p>\n

Jupiter<\/strong><\/h2>\n
\""Jupiter's\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Credit: NASA\/JPL-Caltech\/SwRI\/MSSS\/Kevin M. Gill<\/span><\/figcaption><\/div>\n

Probably the most widespread use of sonification is by amateur astronomers and radio enthusiasts, who regularly tune in to Jupiter<\/a> using short-wave receivers and antennae connected to speakers.<\/p>\n

First discovered in 1955, the radio sounds from Jupiter are diverse.<\/p>\n

They have been described variously as sounding like waves crashing on a beach, woodpeckers and whale song.<\/p>\n