NASA on Monday (22 February) released the first high-quality video of a spacecraft landing on Mars, a three-minute trailer showing the enormous orange and white parachute hurtling open, and the red dust kicking up as rocket engines lowered the rover to the surface.
The footage was so good – and the images so breathtaking – that members of the rover team said they felt like they were riding along.
The Perseverance rover, which landed last Thursday (18 February) near an ancient river delta in Jezero Crater, has also sent a set of sounds recorded on the surface of Mars.
The lone microphone turned on for landing failed, but NASA got some snippets of sound after touchdown – the whirring of the rover’s systems and wind gusts.
In the first set, sounds from the rover itself dominate. In the second set, the sound was filtered to make sounds from Mars more audible.
“That gentle whir that happens in the background, that is a noise made by the rover, but yes, what you did hear ten seconds in was an actual wind gust on the surface of Mars picked up by the microphone and sent back to us here on Earth,” says David Gruel, entry, descent and landing camera suite lead.
“The analysis indicates that was around a five meter per-second type of wind gust. So, we can sit here now and actually tell you that we have recorded sound from the surface of Mars.”
This is the first time a Mars rover has been equipped with a microphone.
NASA equipped the spacecraft with a record 25 cameras and two microphones, many of which were turned on during last week’s descent.
“The microphone will add the fifth sense of the exploration of Mars by listening to the atmosphere,” says Baptiste Chide, a postdoctoral researcher at France’s Institute of Research in Astrophysics and Planetology (IRAP), who is working on the rover’s SuperCam instrument.
“With this microphone we’ll open a new area of Mars exploration. And that was kind of a natural idea to associate the beautiful images and landscape we have on Mars with the sound we hear in that.”
Scientists hope the SuperCam microphone will capture sounds of the rover’s laser turning rocks into plasma, giving them clues to rock properties, including density.
It may also capture sounds of the rover’s Ingenuity helicopter taking flight.
But there may be other helpful applications too, such as listening to the rover’s inner workings to check if everything is working properly.
“The noise is an incredible thing that engineers can use to basically detect the health of moving systems, gears and actuators and things like that,” says Gruel.
But scientists warn audio gathered by the mission will not sound quite the same on Mars as it would to our ears here on Earth.
The red planet’s colder temperature, less dense and mostly carbon dioxide atmosphere mean sounds will appear lower in volume and higher-frequency tones will be strongly diminished.
Chide compares it to “listening through a wall”.
“When your neighbors are partying, you only hear the sounds of the bass, you don’t hear the conversations because the wall, it absorbs all the sounds, it reduces the volume by about 20 decibels, but it filters more of the high frequencies than the low frequencies,” he says.
Perseverance’s microphones aren’t the first sent to Mars.
One was sent on NASA’s failed Mars Polar Lander which crashed into the planet in 1999. Another was sent aboard 2007’s Phoenix Lander but was never turned on.
The Perseverance rover landed last Thursday to search for signs of ancient microscopic life.