The first audio recordings from Mars by NASA’s Perseverance rover indicate that it is a quiet planet but one where sounds have different speeds, scientists said in a study published in the Nature journal last Friday. The study confirmed for the first time that the speed of sound is slower on Mars, travelling at 240 metres a second, compared to 340 metres a second on Earth.
This was expected, it said, because Mars’ atmosphere is 95% carbon dioxide (compared to 0.04% on Earth) and about 100 times thinner, making sound 20 decibels weaker. But they discovered that high-pitched sounds were different from lower frequencies like the whir of a helicopter rotor, unlike on Earth which has just one speed of sound. However, there were few natural sources of sound with the exception of wind, they said.
Read the full story: Phys.org
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