What Mars sounds like, and the rover’s welcome party

Mars is about to be a very busy place when three separate missions arrive at the red planet in February.

One of those missions includes NASA’s Perseverance rover. When it lands, we’ll be able to hear the sounds of Mars for the first time, thanks to microphones riding on the rover.

A new interactive experience shared by the agency will prepare our ears for a key difference in the sounds of Mars: the atmosphere. The thin Martian atmosphere has only 1% of the density that we experience of Earth’s atmosphere at the surface. It also has a different atmospheric composition. Mars is also much colder than Earth. All of these factors will affect sound on Mars, even though the differences may be subtle.

The NASA interactive compares sounds as we hear them on Earth versus how they may sound on Mars, like birds chirping or music. If you were speaking on Mars, your voice would sound more muffled and it would take longer for others to hear you.

So what will we be able to hear on Mars? The microphones are expected to pick up the sounds of the rover landing and working on Mars, as well as ambient noises like wind. One of the microphones is located on top of the rover’s mast, so it can pick up natural sounds and even activity by the rover — like when the rover’s laser zaps rock samples and turns them into plasma to learn more about their composition.

“It is stunning all the science we can get with an instrument as simple as a microphone on Mars,” said Baptiste Chide, a postdoctoral researcher in planetary science at NASA’s Jet Propulsion Laboratory and a contributor to the SuperCam microphone, in a statement.

The other microphone will listen for the sound of pyrotechnic devices that deploy the parachutes during landing and the rover’s wheels moving over the Martian surface.

“Recording audible sounds on Mars is a unique experience,” Chide said. “With the microphones onboard Perseverance, we will add a fifth sense to Mars exploration. It will open a new area of science investigation for both the atmosphere and the surface.”

The Perseverance rover, tasked with the mission of hunting for signs of ancient life, and the Ingenuity helicopter, which will be the first to fly on another planet, are due to land on Mars on February 18.

That doesn’t mean the planet hasn’t been buzzing with activity from the robotic explorers NASA has sent to Mars in recent years.

3,000 days and counting

The Curiosity rover is still going strong and has been investigating Mars since it landed in 2012 — and it has been 3,000 Martian days since Curiosity touched down on the red planet.

Curiosity has gradually climbed Mount Sharp, a mountain that stretches 3 miles up in the center of the 96-mile-wide Gale Crater.

To celebrate 3,000 days on Mars, Curiosity took one of its famed panoramas. Geologists on the mission team were excited to see rocks that look like benches as Curiosity continues its ascent.

The panorama includes 122 individual images that were captured on November 18.

The center of the panorama shows the floor of Gale Crater, and its northern rim is on the horizon. The upper layer of Mount Sharp can be seen to the right.

These benchlike stones form as softer rock layers erode on slopes, leaving behind harder clifflike layers of rock.

“Our science team is excited to figure out how they formed and what they mean for the ancient environment within Gale,” said Ashwin Vasavada, Curiosity’s project scientist, in a statement.

InSight forges ahead without its ‘mole’

The InSight mission, which landed on Mars in 2018, has been extended for another two years and is expected to operate through December 2022, according to a NASA announcement.

Since InSight began investigating Mars, the mission team members have learned more about the planet’s crust and mantle. They have identified a number of Marsquakes and established that Mars is seismically active.

The scientists have also learned more about the Martian atmosphere, magnetic field and the interior structure of the planet.

During the extended mission, InSight will track seismic activity on Mars and study Martian weather.

One thing that won’t be moving on, however, is the seemingly doomed “mole,” or InSight’s heat probe. The probe was intended to bury itself beneath the Martian surface and take the internal temperature of Mars to better understand the heating behind the evolution of the planet.

Martian soil has a tendency to clump, which has proven to be an obstacle to the mole as it has tried to bury itself since February 2019. Simply put, there isn’t enough friction for the mole to hammer itself further down than the 3 centimeters it has reached. Even tapping it with a scoop, located on InSight’s robotic arm, didn’t help.

“We’ve given it everything we’ve got, but Mars and our heroic mole remain incompatible,” said Tilman Spohn, principal investigator of the instrument, in a statement. “Fortunately, we’ve learned a lot that will benefit future missions that attempt to dig into the subsurface.”

This is the first time a mission attempted burrowing beneath the soil on Mars. However, the knowledge gained from this attempt will inform future designs — especially for astronauts that may have to one day dig through Martian soil or instruments that search for subsurface life.

“We are so proud of our team who worked hard to get InSight’s mole deeper into the planet. It was amazing to see them troubleshoot from millions of miles away,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, in a statement. “This is why we take risks at NASA — we have to push the limits of technology to learn what works and what doesn’t.”