Sounds of Mars: NASA Curious Universe Explores Perseverance EDL Microphones and Mars Audio

Episode at a glance

In this episode of NASA's Curious Universe, listeners explore how Mars sounds differ from Earth and how Perseverance's microphones capture ambient audio during the landing and the mission's early science phase. Experts break down the atmospheric physics that mute high frequencies, the seven minutes of descent, and how the data is returned and refined for listening on Earth.

• Mars acoustics explained: CO2-dominated, thin atmosphere lowers the speed of sound and dampens higher pitches.
• EDL overview: separation, atmospheric entry at high speed, supersonic parachute deployment, sky crane, and touchdown.
• Microphones and data processing: off-the-shelf components, data latency, and cleaning to reveal meaningful Mars sounds.
• Rover science and future steps: core rock sampling, laser rock interaction with Supercam, and plans to bring samples back to Earth.

Overview of the podcast

The podcast focuses on the Sounds of Mars episode from NASA's Curious Universe, detailing how Mars acoustics are anticipated to differ from Earth due to the planet's cold, CO2-rich atmosphere and extremely thin air. It introduces Perseverance, its two microphones, and the goal of capturing Mars sounds to accompany seismic and visual observations as humanity plans deeper exploration on the Red Planet.

Mars acoustics and atmosphere

Scientists expect that because Mars’ atmosphere is almost entirely carbon dioxide and about 1% as dense as Earth's at the surface, sound would travel more slowly and carry less energy. The lower density reduces the transmission of higher pitched sounds, making bass-like noises more prominent. An algorithm created by NASA helps model how familiar Earth sounds would be heard on Mars, illustrating how an ocean, bells, bells, chimes, or conversations might be perceived on a world with a thinner, CO2-rich atmosphere. The differences in air composition and density underpin the anticipated muffling and decibel-level differences compared to Earth.

Entry, Descent, and Landing (EDL) and the seven minutes of terror

The episode delves into the critical EDL phase. Perseverance enters Mars’ atmosphere at roughly 12,000 mph, undergoes a sequence of guided entry, deploys a supersonic parachute at Mach 1.7, discards the heat shield to expose radar for altitude and velocity estimation, then uses the descent stage to hover above the surface before the sky crane lowers the rover to the ground. Touchdown marks the moment when the first ambient Mars noises—the wind and other atmospheric sounds captured by the EDL microphone—are recorded and sent back to Earth for processing. The team uses Monte Carlo simulations to model sensor behavior, atmosphere, and terrain to reduce the terror of the first real test of the system and to maximize confidence in a successful soft landing.

Microphones, data handling, and sound processing

Two microphones on Perseverance are highlighted. David Gruel discusses that the hardware is similar to what was sent to Mars, underscoring the off-the-shelf nature of the components. After landing, sound files take time to travel to Earth and require processing to reduce background noise and emphasize signals of interest. The podcast also hints at the potential to hear rock interactions through Supercam’s laser, which zaps rocks and produces sounds that reveal rock composition and other materials present. Finally, the episode teases the broader science mission after landing, including rock core sampling and eventual Earth return missions.

Key insights

• Mars acoustics are shaped by a CO2-dominated, thin atmosphere that lowers the speed of sound and attenuates higher frequencies.
• The EDL sequence is the most perilous part of the mission, tightly choreographed to survive entry, parachute deployment, and sky crane operations.
• The EDL microphone provides the first direct ambient Martian sounds, which are processed and cleaned before Earth delivery.
• Perseverance’s core science includes rock sampling, laser-based rock analysis with Supercam, and plans for sample return missions in the coming years.