NASA’s Insight module landed on Mars on November 26, 2018 to study the deep interior of the planet. Slightly higher than the Sun (Mars year), the fixed lander detected more than 480 earthquakes and collected the most detailed meteorological data from any mission sent to the surface of Mars. The Insight study, which has been struggling to dig underground to measure the planet’s temperature, has also made progress.
The surfaces of Mars and Earth were at one time very similar. Both were hot, humid, and covered in dense atmospheres. But three or four billion years ago, these two worlds followed different paths.
Insight’s mission (seismic investigations, interior exploration using geodesy and heat transfer) is to help scientists compare the Earth to its rusty brother.
Study of the interior composition of Mars. Here are three discoveries about our red neighbors in the sky.
Weak “murmuring” is the norm
The Insight seismometer, provided by the French space agency CNES (Center National D’Tods Spadiels), is sensitive enough to detect small sounds coming from great distances. But it was only in April 2019 that seismic experts from the Marscake Service, in conjunction with EDH Zurich, detected their first Mars earthquake.
Since then, Mars has lost more time, trembles frequently, and, although slower, is more than 3.7 magnitude without earthquakes.
No more than 4 earthquakes Indicates a mystery, Takes into account the frequency at which the Red Planet is shaken by small earthquakes.
“It’s a little surprising that we didn’t see a big event,” said Mark Bonning, NASA’s JBL seismologist in Southern California, who heads the Insight mission. “It may be telling us something about Mars, or it may be saying something about our luck.”
Say it another way: Mars is more stable than predicted – or Insight landed especially during quiet times.
Seismologists will have to wait patiently for these large earthquakes to study the layers beneath the surface. “Sometimes we get big sparks of surprising information, but most of the time they’re just ‘junk food’,” he said. Bruce Bonard JPL, Insight’s primary investigator. “It’s more like trying to follow the path of complex clues than giving answers to a well-decorated gift.”
Wind can cover earthquakes
As Insight began to detect earthquakes, they became more regular, and at one point they occurred every day. Then, at the end of June this year, the findings were basically discontinued. Since then, only five earthquakes have been detected, all of them since September.
Scientists think Mars winds are the reason for these times Earthquake is empty: The planet entered its windy season of Mars in June. This work knew that the wind would affect the sensitivity seismic measurement of the Insight, which was fitted with an anti-wind dome and thermal shield. But the wind still shakes the ground and makes a noise that hides earthquakes.
It may also have contributed to the prolonged seismic silence before Insight’s first detection, as the block landed when a regional dust storm was resolved.
“Before landing, We had to guess how the wind would affect Surface vibrations, ”Bonert said. “We found that we need to focus more on the air because we are working with far smaller events than we focus on on Earth.”
No surface waves
All earthquakes have two sets of waves that travel inland: secondary waves (B waves) and secondary waves (S waves). They also spread over the surface as part of a third type called surface waves.
On Earth, seismologists Use surface waves to learn More about the internal structure of the planet. Before reaching Mars, Insight seismologists expect these waves to give a view of a sub-layer called the mantle at a distance of 400 km from the interior. But Mars continues to offer mysteries: despite hundreds of earthquakes, nothing adds up to surface waves.
“Earthquakes without surface waves are not entirely uncommon, but it was amazing,” Baning said. “For example, we can not see surface waves on the moon, but only because the moon is more scattered than the moon.”
The dry lunar crust is broken more than Earth and Mars, Seismic waves jump in a very wide form that can last more than an hour.
The absence of surface waves on Mars may be linked to extensive fractures within the first 10 km below Insight or the earthquakes detected by Insight come from the depths of the planet because they do not produce strong surface waves.