These are the sounds of Mars: a dust devil … a rover trundling across the surface … the steady sigh of the wind.

All of these sounds were recorded by the Perseverance rover – the first craft to carry microphones to Mars. Scientists have used the recordings to learn more about how sound carries on Mars.

The planet’s atmosphere is less than one percent as thick as Earth’s atmosphere, so it’s much quieter on Mars. It’s especially quiet around noon, when sound waves are bent upward, away from the ground. The atmosphere is also much colder than Earth’s, and it’s made mainly of carbon dioxide. Combined with the air’s low density, on average, sound travels about 30 percent slower on Mars.

And there’s a big difference in both the speed and distance at which different frequencies travel. Higher frequencies die out more quickly, and they move slower. So if you wanted to carry on a conversation – if you could survive without a spacesuit, of course – you’d want a nice, deep voice.

Mars is disappearing in the evening twilight. From the northern part of the country, in fact, it’s probably too low in the twilight to see at all. From south of about Dallas, it looks like a moderately bright star quite low in the west-southwest as twilight begins to fade – silently dropping from sight.

Script by Damond Benningfield