NASA's Interior Exploration with Seismic Surveys, Geodesy and Heat Transport InSight Lander, who landed on Mars just ten days ago, has created the first "sounds" of the Martian winds on the Red Planet. A media conference on these sounds will take place today at 1
InSight sensors detected a haunting deep rumble caused by wind vibrations blowing from 5 to 7 mph (5 to 7 m / h) from northwest to southeast on December 1. The winds were consistent with the direction of the dust devil strips in the landing area observed from orbit.
"Recording this audio was an unplanned pleasure," said Bruce Banerdt, InSight chief investigator at NASA's Jet Propulsion Laboratory (NASL). in Pasadena, California. "One of our goals, however, is to measure movement on Mars, including, of course, movements caused by sound waves."
Two very sensitive spacecraft sensors detected these wind vibrations: an air pressure sensor in the lander and a seismometer sitting on the lander's deck waiting for the InSight robotic arm to deploy. The two instruments recorded the wind noise in different ways. The air pressure sensor, part of the Auxiliary Payload Sensor Subsystem (APSS), which collects meteorological data, records these air vibrations directly. The seismometer recorded land vibrations caused by the wind moving across the solar modules of the spacecraft, which are each 2.2 meters (7 feet) in diameter and project from the sides of the lander like a giant pair of ears.
This is the only phase of the mission in which the Seismic Experiment for Interior Structure SEIS (Seismic Experiment) can capture vibrations generated directly by the lander. In a few weeks, it will be placed on the surface of Mars by InSight's robotic arm and then covered by a curved shield to protect it from wind and temperature changes. It will still detect the movement of the lander, though it passes through the Martian surface. At the moment, vibration data is being recorded that will allow scientists to later remove sounds from the lander when SEIS is on the surface, allowing them to detect better actual Marsquakes.
When earthquakes occur on Earth, their vibrations bounce around our planet and make it "ring", much like a bell produces sound. InSight will determine if trembling or Marsquakes have a similar effect on Mars. SEIS will recognize these vibrations that tell us about the deep interior of the Red Planet. Scientists hope that this will lead to new information about the formation of planets in our solar system, perhaps even on our own planet.
SEIS, France's national center for Études Spatiales (CNES), contains two sets of seismometers. The contributions contributed by the French will be used as soon as SEIS is deployed from the lander's deck. However, SEIS also includes short-term (SP) silicon sensors developed by Imperial College London using electronics from Oxford University in the United Kingdom. These sensors operate on the deck of the lander and can detect vibrations up to frequencies of almost 50 Hertz in the lower range of human hearing.
"The InSight Lander looks like a huge ear," said Tom Pike, member of the InSight science team and sensor designer at Imperial College London. "The solar collectors on the sides of the lander react to wind pressure fluctuations, it's as if InSight hooks its ears and hears how the Martian wind beats on it, and when we look at the direction of the land oscillations emanating from the solar panels, it fits together the expected wind direction at our landing site. "
Pike likened the effect to a flag in the wind. When a flag breaks the wind, it creates air pressure fluctuations that the human ear perceives as fluttering. Regardless, APSS records pressure changes directly from the thin Martian air.
"That's literally the noise – changes in air pressure," said Don Banfield InSights Science Director for APSS at Cornell University in Ithaca, New York. "You always hear that when you talk to someone in the room."
In contrast to the vibrations recorded by the sensors for short periods, the sound of APSS is about 10 hertz below the range of human hearing.
The raw audio sample of the seismometer was released unchanged; A second version has been raised two octaves to make it more perceptible to the human ear, especially when heard over a laptop or mobile speakers. The second audio sample of APSS has been accelerated by a factor of 100, which has shifted it up in frequency.
An even clearer sound from Mars is still pending. In just a few years, NASA's Mars 2020 rover will land on board with two microphones. The first, provided by JPL, is specifically included to record the sound of a Mars landing for the first time. The second is part of the SuperCam and will be able to detect the sound of the instrument laser as it zaps different materials. This helps to identify these materials based on the change in sound frequency.
NASA's Mars InSight bends its arm