Mars Is a Seismically Active World, First Results From NASA's InSight Lander Reveal (space.com) 13
The first results from NASA's quake-hunting InSight Mars lander just came out, and they reveal that Mars is a seismically active planet. Space.com reports: Martian seismicity falls between that of the moon and that of Earth, [says InSight principal investigator Bruce Banerdt, of NASA's Jet Propulsion Laboratory]. "In fact, it's probably close to the kind of seismic activity you would expect to find away from the [tectonic] plate boundaries on Earth and away from highly deformed areas," he said. InSight's observations will help scientists better understand how rocky planets such as Mars, Earth and Venus form and evolve, mission team members have said. The mission's initial science returns, which were published today (Feb. 21) in six papers in the journals Nature Geoscience and Nature Communications, show that InSight is on track to meet that long-term goal, Banerdt said.
The new studies cover the first 10 months of InSight's tenure on Mars, during which the lander detected 174 seismic events. These quakes came in two flavors. One hundred and fifty of them were shallow, small-magnitude tremors whose vibrations propagated through the Martian crust. The other 24 were a bit stronger and deeper, with origins at various locales in the mantle, InSight team members said. (But even those bigger quakes weren't that powerful; they landed in the magnitude 3 to 4 range. Here on Earth, quakes generally must be at least magnitude 5.5 to damage buildings.) That was the tremor tally through September 2019. InSight has been busy since then as well; its total quake count now stands at about 450, Banerdt said. And all of this shaking does indeed originate from Mars itself, he added; as far as the team can tell, none of the vibrations were caused by meteorites hitting the Red Planet. So, there's a lot going on beneath the planet's surface. What's interesting to note is that unlike Earth, where most quakes are caused by tectonic plates sliding around, Mars' quakes are caused by the long-term cooling of the planet since its formation 4.5 billion years ago. "As the planet cools, it contracts, and then the brittle outer layers then have to fracture in order to sort of maintain themselves on the surface," Banerdt said. "That's kind of the long-term source of stresses."
"A wealth of information can be gleaned from InSight's quake measurements," reports Space.com. "For example, analyses of how the seismic waves move through the Martian crust suggest there are small amounts of water mixed in with the rock, mission team members said." They can't say one way or the other whether there are large underground reservoirs of water at this point, but the research is convincing.
The new papers also mention a variety of other discoveries as well. "For example, InSight is the first mission ever to tote a magnetometer to the Martian surface, and that instrument detected a local magnetic field about 10 times stronger than would be expected based on orbital measurements," the report says. "InSight is also taking a wealth of weather data, measuring pressure many times per second and temperature once every few seconds. This information helps the mission team better understand environmental noise that could complicate interpretations of the seismic observations, but it also has considerable stand-alone value."
The new studies cover the first 10 months of InSight's tenure on Mars, during which the lander detected 174 seismic events. These quakes came in two flavors. One hundred and fifty of them were shallow, small-magnitude tremors whose vibrations propagated through the Martian crust. The other 24 were a bit stronger and deeper, with origins at various locales in the mantle, InSight team members said. (But even those bigger quakes weren't that powerful; they landed in the magnitude 3 to 4 range. Here on Earth, quakes generally must be at least magnitude 5.5 to damage buildings.) That was the tremor tally through September 2019. InSight has been busy since then as well; its total quake count now stands at about 450, Banerdt said. And all of this shaking does indeed originate from Mars itself, he added; as far as the team can tell, none of the vibrations were caused by meteorites hitting the Red Planet. So, there's a lot going on beneath the planet's surface. What's interesting to note is that unlike Earth, where most quakes are caused by tectonic plates sliding around, Mars' quakes are caused by the long-term cooling of the planet since its formation 4.5 billion years ago. "As the planet cools, it contracts, and then the brittle outer layers then have to fracture in order to sort of maintain themselves on the surface," Banerdt said. "That's kind of the long-term source of stresses."
"A wealth of information can be gleaned from InSight's quake measurements," reports Space.com. "For example, analyses of how the seismic waves move through the Martian crust suggest there are small amounts of water mixed in with the rock, mission team members said." They can't say one way or the other whether there are large underground reservoirs of water at this point, but the research is convincing.
The new papers also mention a variety of other discoveries as well. "For example, InSight is the first mission ever to tote a magnetometer to the Martian surface, and that instrument detected a local magnetic field about 10 times stronger than would be expected based on orbital measurements," the report says. "InSight is also taking a wealth of weather data, measuring pressure many times per second and temperature once every few seconds. This information helps the mission team better understand environmental noise that could complicate interpretations of the seismic observations, but it also has considerable stand-alone value."
Incredible shrinking planet... (Score:3)
Lots of interesting findings for such a short time on the job. For one, this answers the question of how Mars could be seismically active without tectonic activity. But the magnetometer readings raise another mystery. Why is the field stronger on the surface than orbital readings would suggest. It would be nice to have a couple dozen of these probes arrayed around the planet to provide a global coordinated picture of all this activity. In particular this would make it a lot easier to tease out details like how much water there is under the surface, and where.
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It's a red planet, so I'm going to go out on a limb and guess a higher local concentration of ferrous minerals.
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Ah, interesting. Maybe not much of a magnetic core, but rather a more magnetic crust...
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Yes, it is in the outflow from a volcano that was active 4 billion years ago when there was an active magnetic field
The ferrous particles aligned to the magnetic field as the lava cooled and have remained magnetic since then
It would certainly suggest living underground on Mars and using some sort of heat differential power generation between deep drill sites and the surface
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Lots of interesting findings for such a short time on the job.
Indeed, it's a long overdue mission to have a seismograph on the red planet.
For one, this answers the question of how Mars could be seismically active without tectonic activity.
This (AFAIK) is at least partially due to it still cooling, thus shrinking.
But the magnetometer readings raise another mystery. Why is the field stronger on the surface than orbital readings would suggest.
It is a very good hypothesis that a magnetic field is generated as a result of a solidifying core in rocky planets (e.g. Earth), Mars has long lost it's magnetic field, which got kind of frozen in it's iron reach crust in various ways, with various concentrations - as it's expected to not have a uniform magnetic field. On Earth we can learn about magnetic rev
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Mars has a very "lumpy" magnetic field that varies greatly from one location to the next because it's generated by rocks in the crust that were magnetized in the distant past. There are neat maps made from the orbital data at the MGS site [nasa.gov]. The strong surface field suggests that there are higher local variances than what you can detect from orbit, perhaps just because the distance limits your resolution. It would be really interesting to put this instrument on a rover (or even better, a flyer) to find out ju
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Spin? (Score:1)
I don't see how they can say that. The "mole" digging experiment has been a dismal failure so far and it's 1 of 2 primary experiments, shared with seismology.
Didn't they test the mole in different kinds of soils on Earth? Is Mars dirt really a
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Yes, NASA engineers are known for cutting corners.
If it were just soil then yes, we should have expected the mole to have successfully drilled itself down. I believe the latest indications are that they have, more or less, run into a rock, which th
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I believe they have since decided it's probably the nature of the soil, and not a rock. But being how rocky Mars is on the surface, they should have planned for such regardless, such as quicker rock detection and quicker re-do's.