NASA and other space agencies have been sending spacecraft to
observe the planets in the Solar System. These spacecraft have
instruments capable of capturing radio emissions that are converted
into sound waves to allow scientists and the public to hear the
eerie noise planets make (https://bit.ly/36msDE0).
For instance, people on Earth could hear the sound Mars makes.
It is quieter and more muffled than the noise present on Earth due
to its lower density. These audio clips were captured from a gust
of Martian wind to the snapping sounds of lasers hitting a rock.
The planetary sounds from the spacecraft sent to other planets are
wavelike vibrations of air molecules that occur within the range of
frequencies to which human ears are sensitive, BBC reported.
Sound waves are longitudinal waves that cause particles to vibrate
parallel to the direction it travels through solids, liquids, or gases.
Space.com reported that it is possible to process any other kind
of wave or oscillation and scale it into audible frequencies to
convert these waves into sounds. Scientists have used astronomical
data that often give spooky results associated with Halloween.
The process of converting non-acoustic data into audible sounds
is called sonification which benefits astronomers in understanding
One of the most famous space sounds came from the Rosetta mission
of the European Space Agency (ESA) to comet 67P/Churyumov
-Gerasimenko (Comet 67P/C-G). The sonification was released during
the November 2014 encounter and is based on low-frequency
oscillations in the magnetic field of the comet that was scaled up
by a factor of 10,000 to make them audible.
ESA called it "The Singing Comet" and has become one of the first
pure audio clips that went viral when it was released on SoundCloud.
According to the National Public Radio, it has been heard over 5
Radio astronomy is another promising source of outer space sound.
On Earth, radio waves were initially used for sound broadcasting,
but later on, radio telescopes can transform them into audible
sounds. Fiorella Terenzi is one of the pioneers of acoustic
astronomy, which was used to help in data analysis and later
as a form of science outreach.
Terezi started turning radio waves from distant galaxies in the
universe into audio clips in 1987 when she was still a student,
according to Popular Mechanics. As a professor at Florida
International University, Terenzi used the same techniques in
gathering radio emissions from Jupiter, Saturn, and Earth's
magnetosphere and posted these audio clips on her website.
Other examples of space sounds were captured by NASA's Juno
spacecraft in 2016, which was shared by NASA JPL on YouTube,
and the Cassini probe to Saturn, in which NASA released the
striking audio clip on their website.
More so, Soviet Union's Venera 13 that landed on Venus in March
1982 recorded sounds included the planet's wind and the sound of
the probe hitting the ground. ESA's Huygens Lander also carried
a microphone that recorded the sound of Saturn's moon Titan.