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Mars is a seismically active world, first results from NASA's InSight lander reveal –



Mars may be cold and dry, but it’s far from dead.

The first official science results from NASA’s quake-hunting InSight Mars lander just came out, and they reveal a regularly roiled world.

“We’ve finally, for the first time, established that Mars is a seismically active planet,” InSight principal investigator Bruce Banerdt, of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, said during a teleconference with reporters Thursday (Feb. 20).

Related: Mars InSight in photos: NASA’s mission to probe Martian core

Martian seismicity falls between that of the moon and that of Earth, Banerdt added.

“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.

Probing the Martian subsurface

InSight touched down near the Martian equator in November 2018, kicking off a two-year, $850 million mission to probe the Red Planet’s interior in unprecedented detail. 

The stationary lander carries two main science instruments to do this work: a supersensitive suite of seismometers and a burrowing heat probe dubbed “the mole,” which is designed to get at least 10 feet (3 meters) below the Red Planet’s surface. 

Analyses of marsquake and heat-transport measurements will allow the mission team to construct a detailed, 3D map of the Martian interior, NASA officials have said. In addition, InSight scientists are using radio signals beamed from the lander to track how much Mars wobbles on its axis over time. This information will help researchers determine how big and dense the planet’s core is. (The mission’s full name — Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — references these various lines of investigation.)

Overall, 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. (We have gotten a taste of these results over the past year or so, however, as mission team members have released some findings in dribs and drabs.)

Related: NASA’s Mars InSight lander: 10 surprising facts

Lots of quakes

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.

But that activity is quite different from what we’re used to on Earth, where most quakes are caused by tectonic plates sliding against, over or under each other. Mars doesn’t have active plate tectonics, the researchers said, so both types of 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.”

And some Martian locales are more stressed than others. One particularly active region is the Cerberus Fossae fracture system, which lies about 1,000 miles (1,600 kilometers) east of InSight’s Elysium Planitia landing site.

The mission team traced two of the largest detected marsquakes to Cerberus Fossae, which “contains faults, volcanic flows and liquid water outflow channels with ages as recent as 2-10 Ma [million years ago], and possibly younger from impact crater counts,” Banerdt and his colleagues wrote in one of the new studies.

“So, it’s possible that there’s actual magma at depth that’s cooling,” InSight deputy principal investigator Sue Smrekar, also of JPL, said during Thursday’s teleconference. That cooling would lead to the contraction of the magma chamber, causing deformation of the crust, she added.

But Smrekar stressed that this is a hypothesis, not a definitive determination of what’s going on at Cerberus Fossae. Indeed, though mission team members think they understand Martian seismicity in broad strokes, they’re still trying to nail down how it works in detail.

Related: 7 biggest mysteries of Mars

Many insights

A wealth of information can be gleaned from InSight’s quake measurements. 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. 

“Our data is consistent with a crust which has some moisture in it, but we can’t say one way or the other whether there [are] large underground reservoirs of water at this point,” Banerdt said.

The new papers report 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. (Mars lost its global magnetic field billions of years ago, however. This allowed solar particles to strip away the once-thick Martian atmosphere, which spurred the planet’s transition from a relatively warm and wet world to the cold desert it is today.)

InSight is also taking a wealth of weather data, measuring pressure many times per second and temperature once every few seconds, Banerdt said. 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.

“This is really going to, I think, revolutionize our understanding of the interaction of the atmosphere with the surface of Mars,” Banerdt said. “That’s one of the things that’s really going to open up a whole new window of research on Mars.”

Mole update

Not everything has gone smoothly for InSight, however. Notably, the mole has been unable to get down to its prescribed depth because the Martian dirt is proving more slippery than mission team members had anticipated. (The mole’s self-hammering burrowing system requires a certain amount of friction to work.)

The mission team has tried several strategies to get the mole moving, including pressing on the side of the probe with InSight’s robotic arm to generate the required friction. This latter tactic has generated some halting success, but the mole remains stranded too close to the surface. 

So, in the next six to eight weeks, mission team members aim to try a modification of the arm-pressing strategy, in which they’ll push on the mole’s back rather than its side. The goal is to get the mole about 16 inches (40 centimeters) down, at which point it will hopefully be able to start digging on its own, Banerdt said.

The InSight team would also like a bit more cooperation from Mars on the seismic side of things, if possible. The lander has not yet spotted any truly big quakes, which have the potential to paint a clearer picture of the planet’s deep interior for mission scientists.

The lack of powerful quakes is no surprise, Banerdt stressed; big tremors are much rarer than their smaller counterparts here on Earth, after all. So, the team may have to wait a while to get one.

But such issues aren’t derailing the mission; the team is excited about how things have gone thus far, Banerdt said.

“I think we’re well on our way to getting most, if not all, of the goals that we set for ourselves 10 years ago when we started this mission,” he said.

Mike Wall is the author of “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook

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Dinosaur tail found in Chile stuns scientists – Phys.Org



Miniature models of the Stegouros elengassen, a species of dinosaur discovred in Patagonia in 2018, is seen on display December 1, 2021 in Santiago.

Chilean paleontologists on Wednesday presented their findings on a dinosaur discovered three years ago in Patagonia which they said had a highly unusual tail that has stumped researchers

The remains of the Stegouros elengassen were discovered during excavations in 2018 at Cerro Guido, a site known to harbor numerous fossils, by a team who believed they were dealing with an already known species of dinosaur until they examined its .

“That was the main surprise,” said Alexander Vargas, one of the paleontologists. “This structure is absolutely amazing.”

“The tail was covered with seven pairs of osteoderms … producing a weapon absolutely different from anything we know in any dinosaur,” added the researcher during a presentation of the discovery at the University of Chile.

The osteoderms—structures of bony plaques located in the dermal layers of the skin – were aligned on either side of the tail, making it resemble a large fern.

Paleontologists have discovered 80 percent of the dinosaur’s skeleton and estimate that the animal lived in the area 71 to 74.9 million years ago. It was about two meters (almost seven feet) long, weighed 150 kilograms (330 pounds) and was a herbivore.

According to the scientists, who published their research in the journal Nature, the animal could represent a hitherto unknown lineage of armored dinosaur never seen in the but already identified in the northern part of the continent.

The remains of a Stegouros elengassen, a new species of dinosaur discovered in Patagonia, is seen on display in Santiago Decembe
The remains of a Stegouros elengassen, a new species of dinosaur discovered in Patagonia, is seen on display in Santiago December 1, 20121.

“We don’t know why (the tail) evolved. We do know that within armored dinosaur groups there seems to be a tendency to independently develop different osteoderm-based defense mechanisms,” said Sergio Soto, another member of the team.

The Cerro Guido area, in the Las Chinas valley 3,000 km (1,800 miles) south of Santiago, stretches for 15 kilometers. Various rock outcrops contain numerous fossils.

The finds there allowed the scientists to surmise that present-day America and Antarctica were close to each other millions of years ago.

“There is strong evidence that there is a biogeographic link with other parts of the planet, in this case Antarctica and Australia, because we have two armored there closely related” to the Stegouros, said Soto.

Explore further

New dinosaur species from Chile had a unique slashing tail

More information:
Alexander Vargas, Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile, Nature (2021). DOI: 10.1038/s41586-021-04147-1.

© 2021 AFP

Dinosaur tail found in Chile stuns scientists (2021, December 4)
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Total solar eclipse brings darkness to Antarctic summer –



Video released by NASA shows a total solar eclipse as seen from Western Antarctica on Saturday.

The Earth’s southernmost continent experiences continual daylight from mid-October until early April, but the eclipse brought a few minutes of total darkness.

NASA said the period of totality began at 2:44 a.m. ET. 

A solar eclipse occurs when the moon moves between the sun and Earth, casting a shadow on Earth, fully or partially blocking the sun’s light in some areas.

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For a total eclipse to take place the sun, moon, and Earth must be in a direct line. The only place that this total eclipse could be seen was Antarctica.

The eclipse was also expected to be visible partially from South Africa, Chile, New Zealand and Australia on Saturday.

North America gets its next glimpse of a full solar eclipse on April 8, 2024.

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The International Space Station just swerved to avoid space junk – Deseret News



The International Space Station had to adjust its orbit to avoid colliding with a piece of debris, said Dmitry Rogozin, the head of Russia’s space agency Roscosmos, on Friday, according to CNN.

  • “Five minutes ago, the ISS avoided a conjunction with the U.S. space debris, the Pegasus carrier rocket remnants,” Rogozin said, per the report.
  • According to Sky News, the mission control specialists “calculated how to correct the orbit” of the 100-meter wide space station to protect it from the collision.
  • The engines of Russia’s expendable Progress cargo spacecraft, which is currently docked on the station, will be used to boost the station 1.2 km higher, per the report.

Earlier this week, NASA postponed a spacewalk, originally planned for Tuesday, when it received a space debris warning from ISS.

  • “Due to lack of opportunity to properly assess the risk it could pose to the astronauts, teams have decided to delay the Nov. 30 spacewalk until more information is available,” the agency said via Twitter.

According to Sky News, NASA tracks more than 23,000 pieces of space junk, though there is much more debris too small to track but large enough to threaten human spaceflight.

And these debris travel at speeds up to 17,500 mph. “Even tiny paint flecks can damage a spacecraft when traveling at these velocities,” said NASA.

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