The recent research on sound speed on Mars continues to provide a completely new dimension to exploring the Red Planet. The colder and thinner atmosphere of Mars, which is made overwhelmingly of carbon dioxide, gives rise to fascinating effects.
In a discussion at the 182nd Meeting of the Acoustical Society of America, co-author of the original study Baptiste Chide, of Los Alamos National Lab, explained that the first year of sounds recorded by Perseverance has been distilled to just five hours. You can listen to some of them here.
And the researchers' main takeaway is just how quiet Mars is. The rarefied atmosphere, just 1 percent of the Earth’s own, makes sounds around 20 decibels lower than on Earth and most of the sounds made naturally on Mars come from the wind.
"It is so quiet that, at some point, we thought the microphone was broken!" Chide, said in a statement.
Changes in temperature through the seasons lead to atmospheric changes and in turn, sound loudness can vary by about 20 percent between summer and winter. Also, carbon dioxide tends to be better at attenuating high-pitched sounds with distance.
The rover actually helped confirm the theory that high-frequency sounds travel faster than those at low frequencies. It did that by firing its laser, which surprisingly can be heard on Mars.
"Mars is the only place in the solar system where that happens in the audible bandwidth because of the unique properties of the carbon dioxide molecule that composes the atmosphere," said Chide.