The sound of the wind on Mars was captured for the first time by NASA's InSight lander, which hit the red planet 10 days ago.
On Friday evening, the agency's reaction propulsion laboratory (JPL) released audio clips of the alien wind. InSight collected low frequency rumbles during its first week of operations.
It is estimated that the wind blows between 10 and 15 miles per hour. These are the first sounds of Mars that are detectable by human ears, according to the researchers.
"Capturing this audio was an unplanned treatment," said Bruce Banerdt, InSight's principal investigator in the NASA lab in Pasadena, California. "But one of the things our mission is dedicated to is to measure the movement on Mars and of course it includes the movement caused by the sound waves."
NASA presented the sounds at a Friday press conference. Don Banfield of Cornell University told reporters that they reminded him to "sit outside on a windy summer afternoon … in a sense, that's what it would look like if you were sitting on the InSight on Mars lander."
The scientists involved in the project said that the sound has an otherworldly quality. Thomas Pike from Imperial College London said the rumbling was "quite different from everything we've experienced on Earth, and I think it gives us another way to think about how far we are from these signals."
The noise is of the wind blowing against the InSight solar panels and the resulting vibrations of the entire spacecraft. The sounds were recorded by an air pressure sensor inside the lander that is part of a meteorological station, as well as the seismometer on the spacecraft bridge.
The low frequencies are the result of the very thin air density of Mars, which is almost entirely made up of carbon dioxide and, even more so, by the seismometer itself, which has the purpose of detecting the underground seismic waves that are well below of the threshold of hearing. The seismometer will be moved to the Martian surface in the coming weeks. Until then, the team plans to record more wind noise.
The 1976 Viking landers on Mars picked up the shaking of the spacecraft caused by the wind, but it would be a stretch to consider it healthy, said Banerdt.
InSight landed on Mars on November 26th. "Last week we are still at a very high level from the landing … and here we are less than two weeks from the landing, and we already have some amazing scientific news," said Lori Glaze of NASA, the theatrical direction of the planetary science. "It's beautiful, it's fun."