Nasa Mars rover: The clanking sound of Perseverance's wheels

Jonathan Amos
Science correspondent
@BBCAmoson Twitter

Published
media captionMetal on rock: The sound of Perseverance driving on Mars

Nasa's Perseverance rover has extended its Martian playlist.

After sending back sounds of the wind and the zaps of its laser, the robot has just recorded the noise coming from its metal wheels as they clank across the planet's rocky surface.

"If I heard these sounds driving my car, I'd pull over and call for a tow," joked Dave Gruel, a lead engineer working the rover's cameras and microphones.

Perseverance has two recording devices.

They were included on the robot to give the public a keener sense of what Mars is like, but they also have some scientific value. The nature of the sounds says something about the physical properties of the surface - how hard or how soft the rocks are, for example.

The newly released recording was made during a 27m drive by Perseverance on 7 March. The media at the top of this page is an abridged version of a sequence that runs for 16 minutes in raw form.

Sounds come across a little differently on Mars compared with Earth, due to the much reduced air pressure and contrasting composition. The sounds can seem somewhat muffled. The noise from the wheels is certainly loud, though.

In amongst the clatter, engineers say they can hear a kind of scratching noise, the source of which they are still trying to identify.

They are not sure if this is electromagnetic interference from one of the rover's electronics boxes or just another aspect of the general rattle that is produced in the interaction between the robot's mobility system and the surface.

image copyrightNASA/JPL-CALTECH
image captionEngineers have been trying to identify a location to fly the helicopter

Perseverance landed in Mars' Jezero Crater on 18 February. Most of its time since has been spent testing all its systems, tools and instruments.

An immediate goal is a helicopter experiment. The rover brought a small chopper with it from Earth.

The vehicle is looking for a suitable stretch of terrain where the 2kg device, called Ingenuity, can be put safely on the ground. At present, the aircraft is slung beneath Perseverance's belly.

Nasa says engineers have now identified a likely location which they will discuss in more detail in a briefing on Tuesday next week.

The team behind Ingenuity will be given 30 Martian days, or sols (31 Earth days), to conduct up to five test flights.

image copyrightNASA/JPL-CALTECH
image captionCommissioning has involved discarding various protective covers

Once complete, the main mission can begin. Perseverance is on Mars to search for signs of past life and to collect rocks that can be sent back to Earth later this decade.

An early destination for the robot will be the remains of a delta - a structure built up from the silt and sand dumped by a river as it enters a wider body of water.

In Jezero's case, this wider body was very likely a crater-wide lake that existed billions of years ago.