A year of surprising science from NASA’s Mars InSight mission, The results, explained in a series of six reports released today, show a planet that lives with earthquakes, dust devils, and strange magnetic impulses.
Five articles were published in Nature. An additional paper in Nature Geoscience describes the landing site of the InSight spacecraft, a flat crater nicknamed “Homestead Hollow” in an area called the Elysium Planitia.
InSight is the first mission to see far below the surface of Mars.
Scientific instruments include seismometers that detect earthquakes, wind and air pressure sensors, magnetometers, and heat flow probes to measure the temperature of the planet. A year of surprising science from NASA’s Mars InSight mission.
As the team continues to insert probes to the surface of Mars for their intended purpose, an ultra-sensitive seismometer called the Seismic Internal Structure Experiment (SEIS) has allowed scientists to “hear” many shaking events from hundreds to thousands of kilometers away. .
Seismic waves are influenced by the material in its path, which allows scientists to study the composition of the planet’s internal structure.
Mars can help the team better understand how all rocky planets, including Earth, were formed for the first time.
Mars vibrates more often – but also more gently – than expected. To date, SEIS has identified more than 450 seismic signals, most of which are likely to be earthquakes (in contrast to data noise generated by environmental factors such as wind). A year of surprising science from NASA’s Mars InSight mission.
The biggest earthquake was around 4.0 – not big enough to move under the crust in the lower mantle and the core of the planet.
This is “the most delicious part of apples” when it comes to examining the internal structure of the planet, said Bruce Banerd, chief researcher at InSights at JPL.
Scientists are ready for more: The moon has passed since the InSight landing in November 2018 before the first seismic event was recorded. A year of surprising science from NASA’s Mars InSight mission.
At the end of 2019, SEIS detected about two seismic signals per day, which showed that InSight was affected at a very quiet time. Scientists are still trying to cross fingers for big ones.
Mars does not have tectonic plates like Earth, but there are active volcanic regions that can cause tangles.
Some earthquakes are closely related to such a region, Cerberus Fossae, where scientists see rocks that might have been destroyed by rocks.
Old floods have carved canals along about 800 miles. Then, in the last 10 million years, lava flows have entered this channel – an instant eye in the geological period.
Some of these young lava flows show signs of being shaken by an earthquake less than 2 million years ago. “This is only the youngest tectonic feature on the planet,” said JPL planetary geologist Matt Golombeck. The fact that we see signs of surprise in this region is not surprising, but it is very cool. A year of surprising science from NASA’s Mars InSight mission.
Mars had a magnetic field billions of years ago. It had disappeared, but it had left a ghost behind and pulled the old stones which were now between 61 meters and several miles underground.
InSight is equipped with a magnetometer – the first on the surface of Mars that detects magnetic signals.
The magnetometer has determined that the signal in the Homestead cavity is ten times stronger than expected based on data from orbiting spacecraft that explore the area.
These orbital measurements average a few hundred miles, whereas InSight measurements are more local.
Because most of the surface rocks at the InSight site are too young to be magnetized by previous planetary fields, these magnets must originate from old underground rocks. We combine this data with what we know from seismology and geology to understand the magnetic layer under InSight. A year of surprising science from NASA’s Mars InSight mission.
In addition, scientists are fascinated by how these signals change over time. Measurements vary depending on day and night. They also tend to throb around midnight.
Theories about what caused these changes were made, but one possibility is that they are related to the solar wind, which interacts with the Martian atmosphere.
InSight measures wind speed, wind direction and air pressure almost continuously and provides more data than previous land emissions. The spacecraft’s meteorological sensors have found thousands of swirling vortices known as dust devils when they take sand and become visible.
This site has more vortices than any other place where we landed on Mars with weather sensors.
Despite all this activity and often taking pictures, the InSight camera still does not see dusty demons. But SEIS can feel these vortices that are pulling at the surface like giant vacuum cleaners.
InSight has two radio transmitters: one that sends and receives data on a regular basis, and a stronger radio operator that measures the “vibrations” of Mars as it rotates. A year of surprising science from NASA’s Mars InSight mission.
This X radio frequency, also known as the Rotation and Internal Structure Experiment (RISE), can ultimately provide information about whether the planet’s core is solid or liquid. Solid nuclei mean that Mars fluctuates less than liquid.
This first data year is just the beginning. Observing a full year of Mars (two Earth years) gives scientists a much better idea of the size and speed of vibrations of the planet.