NASA's InSight mission is revealing valuable information about Mars. From recording dozens of earthquakes to the mysterious magnetic pulses that are news these days. They could be lags of an old magnetic field that the red planet had. Not so long ago: a few billion years.
The lost field
The probe data shows that the magnetic field at the landing site on Mars is 10 times stronger than expected. Scientists believe they are generated in nearby sources. It fluctuates on time scales from seconds to days, according to a study published in the journal Nature Geoscience. It is detailed in a statement Catherine Johnson, a professor at the University of British Columbia. She is the lead author of the report.
Before this mission, the best estimates of Martian magnetic fields came from satellites that orbited high above the planet. These new data are the most detailed about this phenomenon.
“Ground level data gives us a much more sensitive image of magnetization in smaller areas. They tell us where it comes from, ”Johnson abounds.
Scientists already knew that Mars had an ancient magnetic field. It mysteriously went out. Most of the rocks on the surface are too young to have been magnetized by this ancient field. The registered field must come from deeper areas.
“We believe that it comes from much older rocks that are buried. Up to ten kilometers underground, ”said Johnson. “We would not have been able to deduce this without the magnetic data. The geological and seismic information is provided by InSight. ”
The InSight sensor captured fluctuations in the magnetic field between day and night. And the mysterious brief magnetic pulses around midnight, which last only a few minutes.
It is due, among other things, to the solar wind and the remaining magnetic field of Mars. “What we are getting is an indirect image of the atmospheric properties of Mars. How charged it becomes and what currents are in the upper atmosphere, ”explained co-author Anna Mittelholz. She is a postdoctoral fellow at the University of British Columbia.
In fifteen months of presence on Mars, the InSight robot and its seismograph have already detected almost 500 tremors.
After 6 months of space travel, the NASA probe landed in November 2018 on the Elysium Martian plain. It allows for the first time that humanity sticks its ear to the ground of the planet.
The earthquakes have not exceeded 4 degrees. Researchers are still waiting for an earthquake with a greater magnitude. Knowing the composition of the red planet will help you understand how it formed. And why the water from its lakes and rivers evaporated about 3.5 billion years ago.