This is what an ordinary day on Mars sounds like

On any given day on the red planet all you hear is a thunderous silence. In this cold and hostile world, located millions of kilometers from Earth and inhabited only by a handful of robots and space probes, the only noise permeating the thin Martian atmosphere is that of the wind. The space rover ‘Perseverance’ has been meticulously recording this sound for a year. The analysis of these audiosbeyond transporting the imagination of earthlings to Mars, has revealed that the speed of sound is slower on the red planet than on Earth. And this, in practice, would imply that a conversation between two people on Mars it would ring late. Or that a song would not sound the same on terrestrial soil as on the Martian sand.

The first analysis of the acoustics of the red planet, recently published in the journal ‘Nature’, is based on the study of different types of sounds captured by the Mars rover during its year of mission. In the recordings of ‘Perseverance’, in fact, only the martian wind is heard. And when the mission performs some task, of course, you can also hear the sound of the wheels of the moving on the ground, the blades of Ingenuity rising or the hammer of the space vehicle to break the rocks.

The study of these recordings has revealed that in the Martian atmosphere the speed of sound is slower than on earth and varies with pitch and frequency. On Earth, under normal conditions, sounds travel at about 343 meters per second (and at a frequency of 767 mph). But on Mars, as data from ‘Perseverance’ have revealed, serious sounds they travel 240 meters per second (537 mph), while high-pitched sounds travel at about 250 meters per second (559 mph). It has also been found that on Mars bass tones only travel about eight meters, while on Earth they can reach up to 65 meters. The treble, on the other hand, barely manage to travel through the atmosphere.

Listen to the muffled hums as I work on Mars. Scientists used my recordings to study how fast sound travels through the thin, mostly CO2 Martian atmosphere, and confirmed that the speed of sound is slower on the Red Planet than on Earth. https://t.co/q3SwJwRjcr pic.twitter.com/NyHjVj9FAh

— NASA’s Perseverance Mars Rover (@NASAPersevere) April 1, 2022

To understand what these differences mean, the US space agency NASA, leader of the ‘Perseverance’ voyage, has put together a playlist comparing what different sounds would be heard on Earth and Mars. The song of a bird, for example, would hardly be heard on the red planet. Neither does the buzz of a bicycle bell. the voice of a persontransported to the red planet, would sound in a very different from what we are used to on terrestrial soil.

The thunderous silence of Mars has surprised even scientists. “It’s all so quiet that at some point even we came to think that the microphones were broken“, explains Sylvestre Maurice, an astrophysicist at the University of Toulouse in France and the main author of the first analysis of Martian acoustics. According to the researcher, despite the fact that The rover’s microphones are extremely sophisticated.the thin Martian atmosphere has become the main obstacle to recording distant sounds.

“Mars is very calm due to low atmospheric pressurebut this is something that also changes with the seasons,” argues Baptiste Chide, a scientist at the Los Alamos National Laboratory in New Mexico and also a co-author of the study. In this sense, the scientists estimate that in the coming months, when autumn begins martians, Mars could get louder and provide even more information about the air of this other world. “Perhaps soon we will discover that the acoustic environment on Mars is now less quiet than when we landed,” says the expert.