Martian landers have successfully measured wind speeds using various methods, such as assessing how quickly heated materials cool when exposed to the wind and capturing images of lightweight indicators that move with the breeze. However, there is still potential for enhancements. Researchers have introduced an innovative sonic anemometric system that uses two narrow-band piezoelectric transducers to calculate the time it takes for sound pulses to travel through the Martian atmosphere. This study also took into consideration factors like transducer diffraction effects and the direction of the wind.
Mars is known for its extremely hostile conditions, where temperatures can vary significantly throughout the day, averaging around minus 80 degrees Fahrenheit. The planet’s surface is largely covered in red dust and is marked by features like craters, canyons, and volcanoes. Additionally, its atmosphere is incredibly thin, with a density of only about 1% compared to Earth’s.
It is no surprise that measuring wind on Mars presents numerous challenges. Martian landers have collected data using methods that either measure the cooling rates of heated objects in the wind or identify “tell-tales” moving in the breeze. These anemometric techniques have provided essential information regarding Mars’ climate and atmosphere.
However, as plans to send astronauts to Mars progress in the next few years, there remains a need for improved scientific tools.
In a recent study published in JASA on behalf of the Acoustical Society of America by AIP Publishing, researchers from Canada and the U.S. unveiled a new sonic anemometric system that includes a pair of narrowband piezoelectric transducers designed to track the travel time of sound pulses in Martian air. The research addressed various factors like the effects of transducer diffraction and wind direction.
“By measuring sound travel time differences in both forward and backward directions, we can precisely gauge wind in three dimensions,” explained author Robert White. “This method offers two significant advantages: it’s quick, and it performs well at low speeds.”
The team aims to capture data on up to 100 wind speeds every second, even at speeds as low as 1 cm/s. This marks a considerable improvement over earlier techniques that could only monitor about one wind speed per second and struggled to record speeds below 50 cm/s.
“By measuring swiftly and accurately, we hope to not just identify average wind speeds but also monitor turbulence and variable winds,” said White. “This is crucial for understanding atmospheric conditions that could affect small vehicles like the Ingenuity helicopter that recently operated on Mars.”
The researchers assessed ultrasonic transducers and sensors across a broad temperature spectrum and a limited pressure range in carbon dioxide, which is the primary gas in Mars’ atmosphere. Their findings indicated that temperature and pressure fluctuations would cause only minimal errors.
“The system we’re creating will be ten times faster and ten times more precise than anything else previously employed,” stated White. “We expect it to deliver more insightful data as future Mars missions are planned and to enhance our understanding of Martian climate, with potential implications for understanding our own planet’s climate as well.”
