AUG 15, 2024

Using sound to measure wind speeds on Mars

WRITTEN BY: Laurence Tognetti, MSc

The planet Mars has several similarities with Earth, including extinct volcanoes, dry lake beds, and active dust storms, the last of which is governed by the Red Planet’s prevailing winds. However, given the average surface pressure of Mars is 0.6 percent of Earth’s due to Mars’ paper-thin atmosphere, which means the wind speeds are far smaller than on Earth. But can we accurately measure this wind speed and how will it contribute to future missions to the Red Planet?

This is what a recent study published in the Journal of the Acoustical Society of America hopes to address as a team of researchers investigated using sound to measure wind speeds on Mars, which holds the potential to help scientists better understand the various processes that comprise the Red Planet and how these processes could influence future missions, as well.

For the study, the researchers used a novel sound device called a sonic anemometric system to measure wind speeds on Mars, which they note exhibits sound behavior equivalent to the Earth’s stratosphere at 30-42 kilometers (18.6-26 miles) in altitude. With their four transducers that comprise the system, the researchers attempted to measure how fast sound pulses travel through the thin Martian air while accounting for how the sound waves travel around obstacles (known as diffraction) and wind direction.

“By measuring sound travel time differences both forward and backward, we can accurately measure wind in three dimensions,” said Dr. Robert White, who is an assistant professor of mechanical engineering at Tufts University and lead author of the study. “The two major advantages of this method are that it’s fast and it works well at low speeds. By measuring quickly and accurately, we hope to be able to measure not only mean winds, but also turbulence and fluctuating winds. This is important for understanding atmospheric variables that could be problematic for small vehicles such as the Ingenuity helicopter that flew on Mars recently.”

Going forward, the researchers aspire to take 100 measurements per second at 1 centimeter per second. For context, current instruments on Mars have only been able to take 1 measurement per second at 50 centimeters per second.

What new discoveries will researchers make about measuring wind speeds on Mars in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

Sources: Journal of the Acoustical Society of America, AIP Publishing, ScienceDaily

Featured Image: A dust devil of Mars captured by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. (Credit: NASA/JPL-Caltech/University of Arizona)