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Martian dust devil seen skipping across the red planet

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Martian dust devil recorded by Curiosity rover at Gale Crater on Sol 2847. Credit: NASA/JPL.

Although Mars’ atmosphere is 100 times thinner than Earth’s, that doesn’t mean that it isn’t just as complex and dynamic in many regards. Mars has cyclonic storms, clouds, seasons, and — as NASA recently illustrated in a fantastic video — dust devils.

This one-of-a-kind footage was recently recorded by Curiosity rover’s Mastcam at Gale Crater. It shows a Martian dust devil casually moving from the left of the frame towards the right.

Seeing the same atmospheric phenomena common on Earth on another planet in such detail is both fascinating and scientifically valuable. Right now, Gale Crater is in its “windy season” and recordings like this can help scientists better understand how atmospheric movements affect Mars’ climate.

Dust devils on Mars form under the same conditions as in Arizona’s desert. These rotating columns of air pick up dust and debris typically on clear summer days when the ground is very hot. The hotter part of the ground heats the air directly above it, whose temperature becomes higher than the surrounding air, so it rises, punching through the cooler air above and creating a vertical column of warm, rising air. If there is a gust of wind, the arrangement is blown sideways.

On Earth, dust devils are pretty small ranging in height from 10 to 100 feet. But in 2012, NASA caught an amazing dust devil that was half a mile tall, and 100 feet wide. It was far from the biggest — dust devils were recorded in the several miles high range.

This particular dust devil recorded on Sol 2847 (a ‘sol’ is a day on Mars) was active for just 5 minutes but the video was fast-forwarded to span just a couple of seconds.

Because they’re much more powerful than on Earth, dust devils on Mars are thought to play an important role in the planet’s climate. These transport vast amounts of fine particles of dust from the surface to the upper atmosphere. The dust alters the albedo or reflectiveness thereby directly influencing the temperature on the surface of Mars.

 

“These give us the most information about dust devils, such as where they initiate, how they evolve, and how much variety there is in size, dust-content, and duration. Looking at how fast they’re moving and in what direction also tells us about the background wind speed and direction at their location,” Claire Newman, Atmospheric Scientist at Aeolis Research, wrote in a NASA blog post.

 

SOURCE:- ZME Science

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If dark matter is a particle, it should get inside red giant stars and change the way they behave – Universe Today

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Dark matter makes up the vast majority of matter in the universe, but we can’t see it. At least, not directly. Whatever the dark matter is, it must interact with everything else in the universe through gravity, and astronomers have found that if too much dark matter collects inside of red giant stars, it can potentially cut their lifetimes in half.

When stars like our sun near the end of their lives, they stop fusing hydrogen in their cores. Instead, the fusion takes place in a shell surrounding a dense core of inert helium – the leftover ash from that nuclear reaction. Over the course of hundreds of millions of years, that core contracts (after all, there’s nothing inside of it generating energy to keep it inflated), heating it up.

Simultaneously, because of the increased core temperature, the rest of the star swells, ballooning to ridiculous proportions as a red giant star.

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Astronomers can estimate the lifetimes of red giant stars by studying the complex physics of the core, tracing how long the helium can continue to heat until it reaches the critical threshold needed for it to undergo its own nuclear fusion, triggering the final end stages of the star.

It’s a pretty straightforward astrophysical calculation.

That is, it’s pretty straightforward unless something jams up the works.

A Dark Heart

Completely unrelated to red giants, astronomers are currently puzzling over the nature of dark matter, a substance that comprises roughly 80% of all the matter in the universe, yet is completely invisible. We’re not exactly sure what dark matter is, but we’re pretty confident that it is some sort of particle, as yet completely unknown to the standard model of particle physics.

Whatever the dark matter is made of, it must interact with normal matter through gravity, because that’s how we’ve been able to detect it so far. Beyond that, it may be possible for dark matter to form clumps, or regions of high density inside normal-matter objects like stars and planets.

Astronomers have already investigated the consequences of pooling dark matter into the hearts of normal stars, but new research has revealed what happens to red giant stars near the end of their lives.

Short version: it’s not pretty.

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According to a paper recently appearing on the preprint journal arXiv, When too much dark matter sits inside a giant star, it causes the helium core to contract more than it normally would. That increased density raises the temperatures, which in turn raises the luminosity, which goes on to make the future evolution of the star that much shorter.

The effects are dramatic. If dark matter makes up a mere 10% of the mass of the red giant core, the temperatures jump by 10%, the luminosity doubles, and the lifetime of the red giant is cut in half.

We don’t know how much dark matter – if any – sits inside red giants, but future studies of this population of dying stars may reveal clues to one of the most enigmatic substances in the universe.

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No less than 5 house rocks headed in the direction of Earth this week, as Japan extends its Hayabusa2 asteroid-hunter mission – Nuhey

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In yet one more cosmic barrage of boulders and particles, NASA is warning of not less than 5 shut asteroid flybys this week, simply days after Japan’s house company introduced it will be extending its asteroid-hunter mission.

To kick issues off, on September 21 the 10-meter and 16-meter 2020 RQ6 and 2020 SJ2 will shoot previous the Earth at distances of 1.2 and 1.four million kilometers respectively. 

Earlier than anybody can breathe a sigh of aid, nonetheless, three extra Close to-Earth Objects are anticipated to fly previous on September 22.

© NASA

At 50m in diameter, or as tall because the Arc de Triomphe, the most important of the three, named 2020 RD5, will cross the Earth at 61,000 kph at a mercifully protected distance of 4 million kilometers. 

Not lengthy after, the paltry-by-comparison 2020 SM2, measuring simply 5.8m in diameter, or 4 Danny DeVitos stacked on prime of each other, will zoom previous Earth, simply 1.2 million km away. 

Citing the rear would be the 27-meter 2020 RB6, touring at a staggering 71,000 kph, set to cross our planet at a ‘shut strategy’ distance of two.5 million km.

Additionally on rt.com

Two asteroids set to cross Earth’s orbit simply hours aside as one other Nice Pyramid-sized house rock barrels our method

In the meantime, Japan’s Hayabusa 2 asteroid hunter, which efficiently landed on and ‘shot’ the asteroid Ryugu with a specialised bullet with the intention to acquire samples for evaluation again on Earth, is ready to increase its mission and contact down on one other house rock. 

The preliminary pattern is because of return to Earth this December, with a deliberate touchdown in Australia. 

Nevertheless, the Japanese Aerospace Exploration Company (JAXA) confirmed at a press briefing late final week that the mission can be prolonged and that, after a flying go to to drop off the pattern, the probe can be headed for the tennis-court-sized 1998 KY26 asteroid, positioned between Venus and Mars. 

Regardless of the obvious proximity to Earth, the spacecraft will spend 5 years cruising across the photo voltaic system earlier than observing yet one more asteroid en path to 1998 KY26, at which level mission management will determine whether or not a touchdown is possible or not.

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Chitin could be used to build tools and habitats on Mars, study finds – Ars Technica

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Enlarge / Scientists mixed chitin—an organic polymer found in abundance in arthropods, as well as fish scales—with a mineral that mimics the properties of Martian soil to create a viable new material for building tools and shelters on Mars.

Space aficionados who dream of one day colonizing Mars must grapple with the stark reality of the planet’s limited natural resources, particularly when it comes to building materials. A team of scientists from the Singapore University of Technology and Design discovered that, using simple chemistry, the organic polymer chitin—contained in the exoskeletons of insects and crustaceans—can easily be transformed into a viable building material for basic tools and habitats. This would require minimal energy and no need for transporting specialized equipment. The scientists described their experiments in a recent paper published in the journal PLOS ONE.

“The technology was originally developed to create circular ecosystems in urban environments,” said co-author Javier Fernandez. “But due to its efficiency, it is also the most efficient and scalable method to produce materials in a closed artificial ecosystem in the extremely scarce environment of a lifeless planet or satellite.”

As we previously reported, NASA has announced an ambitious plan to return American astronauts to the Moon and establish a permanent base there, with an eye toward eventually placing astronauts on Mars. Materials science will be crucial to the Artemis Moon Program’s success, particularly when it comes to the materials needed to construct a viable lunar (or Martian) base. Concrete, for instance, requires a substantial amount of added water in order to be usable in situ, and there is a pronounced short supply of water on both the Moon and Mars. And transport costs would be prohibitively high. NASA estimates that it costs around $10,000 to transport just one pound of material into orbit. 

So there has been much attention on the possibility of using existing materials on the Moon itself to construct a lunar base. Past proposals have called for 3D-printing with Sorel cement, which requires significant amounts of chemicals and water (consumables), and a rocklike material that would require both water and phosphoric acid as a liquid binder. And back in Marcha paper by an international team of scientists suggested that astronauts setting up a base on the Moon could use the urea in their urine as a plasticizer to create a concrete-like building material out of lunar soil.

As with the Moon, any plan to set up a habitable base on Mars must employ manufacturing technologies that make use of the red planet’s regolith. But the authors of the current paper point out that most terrestrial manufacturing strategies that could fit the bill typically require specialized equipment and a hefty amount of energy. However, “Nature presents successful strategies of life adapting to harsh environments,” the authors wrote. “In biological organisms, rigid structures are formed by integrating inorganic filler proceed from the environment at a low energy cost (e.g., calcium carbonate) and incorporated into an organic matrix (e.g., chitin) produced at a relatively high metabolic cost.”

Building a model with a 3D-printed lander module illustrates a possible scenario of fabricating habitats on Mars.
Enlarge / Building a model with a 3D-printed lander module illustrates a possible scenario of fabricating habitats on Mars.
N. Shiwei, S. Dritsas, J.G. Fernandez/PLOS ONE

Fernandez and his colleagues maintain that chitin is likely to be part of any planned artificial ecosystem because it is so plentiful in nature. It’s the primary component of fish scales and fungal cell walls, for example, as well as the exoskeletons of crustaceans and insects. In fact, insects have already been targeted as a key source of protein for a possible Martian base. And since the chitin component of insects has limited nutritional value for humans, extracting it to make building materials “does not hamper or compete with the food supply,” the authors wrote. “Rather, it is a byproduct of it.”

For their experiments, the researchers relied on fairly simple chemistry. They took chitosan derived from shrimp, dissolved it in acetic acid—a common byproduct of both aerobic and anaerobic fermentation—and combined it with a mineral equivalent to Martian soil to create their chitinous building material. They tested its properties by fashioning various objects out of it, most notably a functional wrench, which they tested by tightening a hexagonal bolt. While acknowledging that this would be unlikely to replace metallic tools for certain critical space applications, it proved hardy enough to sustain sufficient torque for small daily tasks.

Think bigger

Next, the team tried molding the material in various geometries to study its potential as a building material via additive manufacturing, ranging from cylinders and cubes to objects with both rounded and angular shapes—including a little humanoid Martian figure. The scientists also demonstrated that the biolith could be used as makeshift mortar to effectively plug a small hole in a pipe. The pipe subsequently went several weeks without leakage. Finally, they built a full 3D-printed model of one possible design for a Martian habitat; it took just under two hours to complete. The researchers concluded that their results demonstrated the feasibility of such “closed-loop, zero-waste” solutions on Mars.

“Bioinspired manufacturing and sustainable materials are not a substituting technology for synthetic polymers, but an enabling technology defining a new paradigm in manufacturing, and allowing to do things that are unachievable by the synthetic counterparts,” said Fernandez. “We have demonstrated that they are key not only for our sustainability on Earth but also for one of the next biggest achievements of humanity: our transformation into an interplanetary species.”

DOI: PLOS ONE, 2020. 10.1371/journal.pone.0238606 (About DOIs).

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