Tag Archives: space

Astronauts Plant Trees in Russia That Tower Above Politics

Cosmonaut-grove

Trees line the path of Cosmonaut Grove at the Baikonur Cosmodrome in Russia.
Image: Flickr, Eugene Kaspersky

In their last days on Earth before launching to the International Space Station, astronauts sees the same thing: two rows of trees that punctuate the otherwise austere landscape outside the space launch facility in Baikonur, Russia.

The trees that outline the T-shaped path are mismatched in size, but that’s for a reason. Each one was planted by an astronaut just before he or she launched to space, a tradition that Yuri Gagarin started 50 years ago when he planted the first tree just before he became the first human in space. His tree is the largest.

A fresh three-member crew — Russian cosmonaut Maxim Suraev, NASA astronaut Reid Wiseman and European astronaut Alexander Gerst — will launch to the ISS on Wednesday. All three astronauts planted their trees last week.

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Expedition 40/41 crew (from left) NASA astronaut Reid Wiseman, Roscosmos commander Maxim Suraev and ESA astronaut Alexander Gerst during the traditional tree-planting ceremony in the run-up to their launch to the ISS on May 28.

Image: European Space Agency

“There’s a whole wealth of Russian traditions,” NASA astronaut Tom Marshburn, who planted a tree before his mission in 2012, told Mashable. “Some are funny, some are beautiful.”

Marshburn-Hadfield-Tree

t the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 34 crew members Flight Engineer Chris Hadfield of the Canadian Space Agency (left), Soyuz Commander Roman Romanenko (center) and NASA Flight Engineer Tom Marshburn (right) pose for pictures Dec. 13, 2012 at the site of their tree planting.

Image: NASA

Many Russian traditions are based on the success of what a cosmonaut did before. “In a lot of ways, it’s about honoring the person who came before you,” Marshburn said.

The simple ceremony always takes place shortly before launch, no matter the environment. Be it a harsh Russian winter or an even colder political standoff, the tree will be planted.

But given the current political climate between the U.S. and Russia, these trees have a deeper meaning within the space community, which, until very recently, has been able to operate above bureaucratic squabble.

As the U.S. continues to unleash sanctions against Russia for its involvement in the crisis in Ukraine, both nations have put targets on the backs of each other’s space programs.

In April, NASA sent a memo to employees stating that it was cutting all ties with Russia, except for when it comes to the space station — as the U.S. depends on Russia to launch its astronauts to the ISS.

At the same time, NASA made a grandiose public statement that it would return spaceflight to the U.S. by 2017, completely nixing the need for Russian involvement at all.

“We’re now looking at launching from U.S. soil in 2017,” NASA spokesperson Allard Beutel told Mashable in April. “The choice here is between fully funding the plan to bring space launches back to America or continuing to send millions of dollars to the Russians. It’s that simple.”

Although NASA, at the time, said politics wouldn’t make it to the space station, Russia unveiled a different plan just weeks later. Russian Deputy Prime Minister Dmitry Rogozin told reporters on May 13 that Moscow would deny U.S. requests to use the ISS after 2020. He also said he would prevent the U.S. from using Russian-made rocket engines to launch military satellites.

Astronauts, however, have subtly voiced their continued commitment to teamwork — a seemingly passive protest to the two countries’ efforts to drag the ISS into their battle.

Canadian astronaut Chris Hadfield, who planted his own tree alongside Marshburn, is among the most vocal. In an April interview with RT, the ISS commander condemned weaponizing space.

And just hours after the news broke that Russia wanted to ban the U.S. from the ISS — coincidentally, that was on the same day a crew of both American and Russian astronauts was returning to Earth — Hadfield tweeted this:

And just on day after the U.S. issued its first round of sanctions against Russia, NASA released the photo below before a scheduled launch, showing the two flags together.

Russia-US-Space

The flags of the countries representing the crew members of Soyuz TMA-12M are seen at the Russian Mission Control Center in Korolev, Russia on Friday, March 28, 2014.

Image: NASA

“Living in space really does break down barriers,” Marshburn said. “It is a family up there. We have to survive.”

Even NASA Administrator Charles Bolden said in March — around the time Russia invaded Crimea — that the space station has been the cornerstone of peaceful relations.

During a press conference, Bolden, who commanded the first U.S.-Russian space shuttle mission in 1994, told the story of flying with Russian cosmonauts only a few years after the Cold War. The men talked of their families and of their aspirations for the world over dinner.

“I found that our relationship with the Russians in the space program has been the same ever since,” Bolden said. “We have weathered the storm through lots of contingencies.”

For his part, Marshburn, who is currently training in Houston for a future ISS mission, said he will continue to work as though the next trip will be with Russia. He’ll still study Russian, and he’ll work with Russian cosmonaut colleagues on site.

“We are well padded from the political goings on,” said Marshburn. “So, I just don’t think about it because who knows where it’s going to go.”

And as long as NASA astronauts climb into a Russian spacecraft, they’ll continue to add their tree to the growing grove around the Baikonur Cosmodrome as well.

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Read more: http://mashable.com/2014/05/28/nasa-russia-tree-cosmodrome/

Hubble Snaps Photo of ‘Christmas Ornament’ Nebula

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It’s the time of year when even the scientists at NASA get into the holiday spirit. Last year, the space agency’s Wide-field Infrared Survey Explorer snapped an image of a cosmic Christmas wreath for the holiday season.

Not be outdone, the venerable Hubble Space Telescope delivered holiday cheer in the form of this image of NGC 5189, a nebula that — if you’re brimming over with holiday cheer or just squinting a little — resembles a very merry Christmas ornament wrapped in a festive ribbon.

You can take a trip through the cosmos to zoom in on the nebula just like the Hubble did in the short video below.

Is the “ornament” interpretation meeting astronomers — and we suspect NASA’s PR wonks — more than halfway? Yeah, probably a little more than half, but come on — ’tis the season. You can afford to be that generous, right?

Either way, we can all agree that the beauty of the image on its own is enough to make you smile.

Image courtesy of NASA

This article originally published at Geekosystem
here

Read more: http://mashable.com/2012/12/19/christmas-ornament-nebula/

North Korea Plans Satellite Launch Later This Month

Over the next three weeks, North Korea plans to launch an Earth observation satellite into space.

North Korea has informed the International Maritime Organisation wing of the UN that it plans to launch the latest Kwangmyngsng satellite sometime between February 8 and25. The hermit regime also poked its head out to report itsplans to the UNs International Telecommunication Union, who help manage the worlds satellites’ orbits.

It all sounds very official, but the North Korean National Aerospace Development Administration (NADA) isnt likely to be replacing NASA any time soon.

The North Koreans have a chequered past in their space program’s short history. Since 1998, NADAhasattempted five satellite launches. Four of these have been flops. The fifth Kwangmyngsng-3 Unit 2 launched in December 2012, and managed to enter orbit.

Although this launch madeNorth Korea the world’s 10th countryto successfullysend an objectintoorbit,several weeks laterthe satelliteappeared to be broken and was”twirling around” aimlessly, Associated Pressreported

Although North Koreaproclaimsthat the satellite will be used for purely scientific purposes, the international community isnt convinced. The plan was announced less than a month after itshydrogen bomb test, leading many to believe this launch is just a guise forlong-range ballistic missile tests. This, along with decades of historic tension with the wider world, has led the United States, South Korea and Japan to already condemnthe plan.

Main image credit: (stephan)/Flickr. (CC BY-SA 2.0)

Read more: http://www.iflscience.com/space/north-korea-plan-satellite-launch-later-month-0

How NASA Keeps Earth’s Germs Out of Space

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In 1967, the United States joined the United Kingdom and the Soviet Union in signing the “Outer Space Treaty,” which remains the closest thing the world has to “space law.” It stipulates, among other things, that as countries explore space they should avoid contaminating it with the microbial life of Earth.

So while we may talk, with a mixture of fantasy and inevitability, about the colonization of other planets by humans, NASA takes great pains to avoid colonizing those bodies with life of a different variety: bacteria and spores that might hitchhike their way through the galaxy via American spacecraft.

But keeping space free of earthly critters is a difficult task. In fact, it’s an effectively impossible one. Curiosity, for example, was not completely sterile at its launch; rather, the rover was built to ensure that it would “carry a total of no more than 300,000 bacterial spores on any surface from which the spores could get into the Martian environment.”

In that way, Curiosity is like the Mars landers that preceded it: just a tiny bit dirty. “When we clean these things, it’s virtually impossible to get them completely, totally, 100% clean, without any organic material at all,” says Dave Lavery, NASA’s program executive for solar system exploration.

Instead, he says the agency enforces “allowable limits” — a kind of controlled biological chaos — that aims to mitigate, rather than eliminate, microbial life on its vehicles. The margins here are extraordinarily slim: When you’re talking about microorganisms, 300,000 across the entire spacecraft is actually a remarkably low number. (A human adult, after all, can play host to a href=”http://discovermagazine.com/2011/mar/04-trillions-microbes-call-us-home-help-keep-healthy” target=”_blank”>as many as 200 trillion microorganisms. Trillion, with a T.)

To keep the Mars Science Laboratory mission within its 300,0000-critter range, the technicians who built Curiosity regularly cleaned the rover’s surfaces — and those of the spacecraft that delivered it to Mars — by wiping them with an alcohol solution.

They baked the mechanical components that could tolerate high heats to kill the microbes that remained. And they sealed off Curiosity’s core box, which contains its main computer and other key electronics, to prevent any traveling microbes from escaping its confines.

Pictured in the video below, the clean room at the Jet Propulsion Laboratory is where Curiosity spent much of its pre-Martian existence. Note the bunny suits worn by the technicians, the better to ensure that human microbes wouldn’t be transferred to NASA’s now-rove-ready rover.

For its standard antibiotic regimen, Lavery says NASA has three main goals. First, of course, there’s scientific accuracy — since, for many of the agency’s missions, the subtext if not the stated objective is to learn about the life that might exist beyond our atmosphere. “If we’ve taken Earth bugs with us, it defeats the entire purpose,” he says.

Second, there’s the Outer Space Treaty and the desire to be a good steward of space — by avoiding contamination of the world beyond Earth’s borders. Third, there’s protecting Earth itself — not just by preventing the passage of earthly life into space, but also by preventing any extraterrestrial life from coming back. (Hence those amazing photos of Armstrong, Aldrin and Collins hanging out in their decontamination module after completing the Apollo 11 mission.)

Planetary protection has been one of the protocols that has unified NASA’s missions since they started as missions in the first place. It’s been a priority, Lavery notes, “since the very beginning of the space program.”

And yet sterilization, just like other NASA protocols, varies significantly by mission. The particulars are determined by two broad considerations: where a mission is going and what kind of spacecraft it’s using to get there. There’s an overall cleanliness standard that’s in place for every mission, Lavery notes — no earth bugs being the general goal — but beyond that, there’s a procedural spectrum NASA employs to determine its approach to decontamination.

For vehicles like the Voyager crafts, wandering the void of space with no planetary destination in mind, standards can be (relatively) less stringent. For a lander like Curiosity, however — or like the lunar modules that brought human life to the moon during the Apollo missions — the sterilization standards are stricter. Because, harsh as those environments may be to earthly life, large or small, there’s a far greater chance that life would find a way to survive in those environments than elsewhere.

We already know, for example, about the space-surviving skills of the tardigrade. And just recently, scientists discovered a species of bacteria able to survive in a lava tube, gleaning energy from a chemical reaction with the iron from basalt rock — precisely the kind of rock abundant on Mars.

Given all that, NASA ranks its missions into five general Planetary Protection categories:

nasa_pp.png

So why not simply give every mission, by default, the highest cleanliness standard, just to be safe? Because sterilization, like pretty much every protocol NASA goes through, isn’t cheap. It’s budgetary concerns, ultimately — and resource concerns more generally — that make decontamination a matter of calculated risk.

Because of that, NASA’s attempts at preventing cross-planet contamination have relied not just on antibiotic practices, but also on a near-universal feature of earthly life: its fragility. Catherine Conley, NASA’s planetary protection officer, last year told Becca Rosen about the slim likelihood of biological commerce between Earth and Mars.

While Conley suspects NASA has transported things like bacteria and pollen spores and other pieces of life inside its spacecraft, there’s been a big caveat to the potential of contamination: “The surface conditions on Mars are pretty hostile to Earth life,” Conley says. Which means that “it’s not very likely that those organisms could actually reproduce, or even survive if they came off the spacecraft.”

Curiosity relies on the same slim odds. And the Mars Science Laboratory Mission, with a roving lander as its vehicle, is ranked as a Category IV. There are subclasses within that category, Lavery points out, based on the different environments Curiosity will be exploring within Mars itself. Just like on Earth, some areas of Mars are more (potentially) hospitable to life than others.

But protocols can also evolve. For Curiosity, the process of selecting exploration sites on Mars took place simultaneously with the process of its design — meaning that a shift in one led to a shift in the other. The Mars Science Laboratory mission started out as a Category IVa — the most stringent possible for landers and probes. (“We wanted to give ourselves as much leeway as we could,” Lavery explains.)

But when the Gale Crater was chosen as Curiosity’s landing site, NASA engineers realized that the IVa classification was “a little bit of overkill,” Lavery says, and downgraded the category — since, given the crater’s aridity, there was virtually no chance that Curiosity would encounter water or ice or anything else that could potentially foster life.

At the same time, engineers at JPL began to rethink the strategy they’d built for the rover’s drill bits. Growing increasingly concerned that a rough landing could damage the rover and the drill mechanism it would rely on so heavily to do much of its work on Mars, the engineers decided to open its previously sterilized box to add a new drill bit to Curiosity’s suite — thus ensuring that, even if one got damaged, another would remain to carry out the mission.

This switch-up, which wasn’t communicated until later to NASA’s planetary protection staff, is the subject of a recent Los Angeles Times article about the “rift” between microbiologists and engineers at the agency.

The notion of a strong divide at NASA might have been a bit overblown, though. The changes made to Curiosity, being not immediately communicated to Conley, were indeed a bureaucratic “slip-up.”

But, beyond that, not only did the implemented changes follow NASA procedure, Lavery says; they were also standard practice — part of the normal evolution of spacecraft design as it accounts for changes made to mission objectives. The mission changed; the vehicle changed along with it. And there’s always that magic 300,000-critter standard. Before Curiosity was launched, “We were able to do an assay that said we were well under that number,” Lavery says. “And we were good to go.”

The question remains, though: What if Curiosity does find water? Probabilistically, that’s unlikely. But Martian water — or Martian ice — is certainly not an impossibility. Particularly given the fact that Curiosity’s work involves drilling into the Martian crust. If the rover does encounter water, any earth-borne microbes lingering on its drill might simply perish in the harsh temperatures and atmosphere of the Red Planet. On the other hand, though … they could survive.

NASA will deal with that possibility when — and, more likely, if — it comes. There are procedures for that circumstance, too. As Lavery points out, those procedures would include NASA’s mission operators, its scientists and its planetary protection officers in a discussion about the best way to move forward. Procedures meant to avoid terraforming of the unintentional variety — procedures meant to ensure that, as we explore Mars, we don’t end up colonizing it, as well.”

This article originally published at The Atlantic
here

Read more: http://mashable.com/2012/09/11/nasa-space-germs/

Saturn’s Glorious Rings Dazzle in NASA Photo

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Saturn’s southern reaches are draped in the shadow of the huge planet’s iconic ring system in a spectacular new picture from NASA’s Cassini spacecraft.

The near-infrared photo, which Cassini snapped on June 15, looks toward the southern, unlit side of Saturn’s rings from 14 degrees below the ringplane, researchers said. The spacecraft was about 1.8 million miles from Saturn at the time. The image scale is 11 miles per pixel.

Saturn’s ice-covered moon Enceladus, which is 313 miles wide, is visible as a tiny, bright speck in the lower lefthand corner of the image.

Many researchers regard Enceladus as one of the best bets in our solar system to host life beyond Earth. Though surface temperatures on the moon are frigid, Enceladus is believed to harbor a vast ocean of liquid water beneath its icy shell.

Enceladus also boasts huge amounts of internal heat, which power a system of geysers that erupt from the moon’s south polar regions. Cassini discovered these geysers in 2005 and has snapped many photos of them since.

The $3.2 billion Cassini mission is a collaboration involving NASA, the European Space Agency and the Italian Space Agency. The spacecraft launched in 1997 and arrived at Saturn in 2004. It has been studying the ringed planet and its many moons ever since, and should continue to do so for years to come. The Cassini mission has been extended to at least 2017.

In early 2005, Cassini’s Huygens lander, an ESA probe, touched down on the enormous moon Titan and relayed the first photos ever from the surface of that intriguing world.

Titan has a thick, nitrogen-dominated atmosphere and a weather system based on methane and ethane, which have pooled to form lakes in various places across the moon’s surface.

This article originally published at Space.com
here

Read more: http://mashable.com/2012/10/01/saturn-rings-nasa-photo/

9 Terrifyingly Awesome Facts About Asteroids

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asteroid

Phil Plait, also known as the “Bad Astronomer,” is a Discover columnist known for making really complicated space stuff (Black holes! White dwarves! Spacetime!) not only totally understandable, but completely fascinating.

Plait made a stop in Portland, Ore. on tour with his latest book, Death from the Skies, to speak at Science Pub, a monthly summit of beer and geeks hosted by Portland’s excellent science museum, OMSI.

Plait’s talk was packed to the gills with both avid Bad Astronomy fans and science-minded folks curious about an astronomer’s take on the end of the world. Here are our favorite asteroid factoids.

1. Objects From Space Hit the Earth… A lot

We see mini-asteroids (meteoroids) crossing paths with Earth quite often, but most of time they fall to the earth as no bigger than a grain of sand or burn up altogether. “It seems like these things are whizzing past us all the time,” Plait says. “That’s because they are.”

2. Asteroids Kind of Look Like Potatoes… Or Dog Bones

According to Phil Plait, it’s a common fact that asteroids often look a lot like potatoes. But Kleopatra, one of Plait’s favorites, is as big as a state and shaped like a dog bone. Kleopatra is actually so big that it has a couple of moons orbiting it as it tumbles through space.

3. Asteroids Can Have Mountains Taller Than Mount Everest

The asteroid known as Vesta boasts a mountain that puts even Everest to shame. And Vesta isn’t the biggest asteroid around, either — that honor goes to Ceres, a dwarf planet that’s 590 miles in diameter.

4. The biggest Asteroid Was Discovered in 1801

We’ve known about Ceres since 1801, when Italian astronomer Giuseppe Piazzi came across the massive body of rock and ice while looking for a star. He initially believed it to be a comet, but now we know Ceres to be much more on par with the size of a small planet.

5. Hollywood Usually Gets it Wrong

Plait thinks Armegeddon is up there with the least scientifically accurate movies ever cooked up in Hollywood. In Armageddon, an asteroid headed toward Earth is blown up into two halves. Among the inaccuracies, Plait noted that there’s no asteroid as big as Texas and if there was we’d know about it for well more than 18 days before it was set to impact Earth.

But not all movies go quite so wrong. Plait does like Deep Impact, another film about an asteroid hitting Earth from the same year. Plait thinks the depiction of the asteroid’s impact and its ensuing wildfires and tsunamis is actually “fairly accurate.” That’s terrifying.

6. Even Tiny Asteroids Are Dangerous

The main reason asteroids are dangerous is because they’re hurtling through space so fast. Asteroids fall to Earth at 50 times the speed of a rifle bullet. An asteroid’s impact could well exceed 50 megatons, the impact of the Soviet Union’s AN602 hydrogen bomb and the largest nuclear weapon ever detonated on Earth. You can even play around with an asteroid impact calculator if you’re curious about just how devastating an Earth impact could be.

7. A Group of Scientists Is Taking the End of the World Very, Very Seriously

The B612 foundation is a privately funded organization on a mission to create a “comprehensive, dynamic map” of the inner solar system. The map will identify the current location of asteroids that could pose a threat to Earth and provide data on just how close to Earth they might pass in the future. Worried? You probably should be. You can always donate to the B612 foundation — it might help you sleep at night.

8. Scientists Are Monitoring an Asteroid Headed for Earth in 2029

An asteroid called Apophis is set to pass near the Earth in 2029. Initial calculations gave Apophis a 2.7% chance of striking our planet. Now we know that Apophis’s odds are much, much smaller. But the asteroid could still pass through a half mile-wide area called a “keyhole,” which would change its orbit and up its chances of impacting the Earth on April 13, 2036.

9. How to Fend Off an Asteroid: Whack it, Don’t Blow it up

It sounds like science fiction, but according to Plait, “The idea is now that if you see one of these things coming, you send a probe at it and you smack it.” Even a tiny shift in an asteroid’s velocity and path can make a huge difference if it’s impacted when far enough away in space.

Another option would be harder to pull off: “You could land a rocket on it and push it, but it would be almost impossible to physically land on it, especially for asteroids like Kleopatra that are tumbling.” That asteroid, the one shaped like a dog bone, has an irregular orbit that would make a landing hard to stick.

Learn anything surprising? We certainly did!

This article originally published at Tecca
here

Read more: http://mashable.com/2012/08/17/facts-about-asteroids/

Pluto’s New Moon: 5 Fun Facts

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Scientists announced the discovery of a new moon around Pluto on July 11, bringing the dwarf planet’s number of known satellites to five.

Researchers using NASA’s Hubble Space Telescope spotted the newfound Pluto moon. The instrument has also found three other Pluto satellites — P4 last year, and Nix and Hydra in 2005. (The dwarf planet’s other known moon, Charon, was discovered in 1978 at the United States Naval Observatory Flagstaff Station in Arizona.)

Here are a few fun facts about the new moon:

1. Its Name is a Mouthful

The fifth Pluto moon has been provisionally named S/2012 (134340) 1, but it’s unlikely anyone other than astronomers will ever call it that. The satellite also currently goes by the less clunky moniker P5, though that won’t last forever.

The International Astronomical Union oversees the naming of celestial bodies, and its guidelines stipulate that objects in Pluto’s neighborhood receive mythological names associated with the underworld. Pluto, Charon, Nix and Hydra already meet this requirement; P4 and P5 will someday, too.

It’s a Tiny Satellite

P5 is nothing like our own moon, a giant orb massive enough to be rounded into a sphere by its own gravity. Rather, researchers think P5 is irregularly shaped, with a diameter between 6 and 15 miles.

P5 is thus likely the smallest of Pluto’s known satellites. Charon measures 648 miles across, Nix and Hydra range between 20 and 70 miles wide, and P4 is thought to be 8 to 21 miles across. [The Moons of Pluto Revealed (Photos)]

For comparison, Earth’s moon is roughly 2,150 miles wide.

3. It’s Not Too Far From Pluto

P5 zips around Pluto at an average distance of 29,000 miles, placing it outside the orbit of Charon but inside the orbits of Nix, Hydra and P4. The orbits of all five known Pluto moons are roughly coplanar, researchers said.

Earth’s moon, on the other hand, circles our planet from about 239,000 miles away.

4. P5 Makes Spacecraft Operators Nervous

P5’s discovery is exciting for researchers who study the outer solar system, but it’s likely causing some of them a bit of anxiety as well.

NASA’s New Horizons spacecraft is headed to Pluto for a 2015 flyby of the dwarf planet. The detection of P5, and P4 last year, show that the Pluto system is more crowded than scientists had thought. So New Horizons may have to watch its step, since a collision with a particle as small as a BB could take the fast-moving spacecraft out.

“We’re finding more and more, so our concern about hazards is going up,” New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colo., told SPACE.com.

Stern and others are pointing Hubble at the Pluto system to get a better handle on those hazards, and the inventory they produce should help minimize New Horizons’ risks, researchers said.

5. It May be Shrapnel From a Huge Collision

At roughly 1,430 miles across, Pluto is considerably smaller than Earth’s moon. So researchers are intrigued by its complex collection of satellites.

Scientists currently think that all five of Pluto’s known moons are relics of a massive collision between the dwarf planet and another large object in the Kuiper Belt — the ring of icy bodies beyond Neptune’s orbit — long ago.

Image courtesy of NASA, ESA and M. Showalter (SETI Institute)

This article originally published at Space.com
here

Read more: http://mashable.com/2012/07/11/pluto-p5-new-moon/

50-Mile Landslides Spotted on Saturn’s Icy Moon

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Long landslides spotted on Saturn’s moon, Iapetus, could help provide clues to similar movements of material on Earth. Scientists studying the icy satellite have determined that flash heating could cause falling ice to travel 10 to 15 times farther than previously expected on Iapetus.

Extended landslides can be found on Mars and Earth, but are more likely to be composed of rock than ice. Despite the differences in materials, scientists believe there could be a link between the long-tumbling debris on all three bodies.

“We think there’s more likely a common mechanism for all of this, and we want to be able to explain all of the observations,” lead scientist Kelsi Singer of Washington University told SPACE.com.

Rock-Hard Ice on Saturn’s Moon

Giant landslides stretching as far as 50 miles litter the surface of Iapetus. Singer and her team identified 30 such displacements by studying images taken by NASA’s Cassini spacecraft.

More From Space.com: Photos: Latest Saturn Photos from NASA’s Cassini Orbiter

Composed almost completely of ice, Iapetus already stands out from other moons. While most bodies in the solar system have rocky mantles and metallic cores, with an icy layer on top, scientists think Iapetus is composed almost completely of frozen water. There are bits of rock and carbonaceous material that make half the moon appear darker than the other, but this seems to be only a surface feature.

Ice on Iapetus is different from ice found on Earth. Because the moon’s temperature can get as low as 300 degrees Fahrenheit, the moon’s ice is very hard and very dry.

“It’s more like what we experience on Earth as rock, just because it’s so cold,” Singer said.

Slow-moving ice creates a lot of friction, so when the ice falls from high places, scientists expected that it would behave much like rock on Earth does. Instead, they found that it traveled significantly farther than predicted.

How far a landslide runs is usually related to how far it falls, Singer explained. Most of the time, debris of any type loses energy before traveling twice the distance it fell from. But on Iapetus, the pieces of ice move 20 to 30 times as far as their falling height.

Flash heating could be providing that extra push.

Flash heating occurs when material falls so fast that the heat doesn’t have time to dissipate. Instead, it stays concentrated in small areas, reducing the friction between the sliding objects and allowing them to travel faster and farther than they would under normal conditions.

“They’re almost acting more like a fluid,” Singer said.

On Iapetus, falling material has a good chance of reaching great speeds because there are a number of great heights to fall from. The moon hosts a ring of mountains around its bulging equator that can tower as high as 12 miles, and the longest run-outs discovered are associated with the ridge and with impact-basin walls.

Scientists think that the landslides are relatively recent, and could have been triggered by impacts in the last billion years or so.

“You don’t see a lot of small craters on the landslide material itself,” Singer said, although the surrounding terrain boasts evidence of bombardment. Over time, landscapes tend to be dotted by falling rocks, so the less cratered a surface is, the younger it is thought to be.

More From Space.com: Photos of Saturn’s Moons

Resting on the ridges and walls, the material gradually becomes more unstable. Close impacts could set them off, but powerful, distant impacts reverberating through the ice could also send them tumbling.

The research was published in the July 29 issue of the journal Nature Geoscience.

Connecting Ice and Rock

Differences in gravity, atmosphere and water content make landslides seen on Iapetus difficult to duplicate in the laboratory. But the fact that they happen on different types of worlds makes it more likely that the mechanism triggering the extended slide is dependent on things unique to either environment.

“We have them on Iapetus, Earth and Mars,” Singer said. “Theoretically, they should be very similar.”

Singer pointed out the implications for friction within fault lines, which produces earthquakes. As plates on Earth move, the rocks within a fault snag on each other, until forces drag them apart.

But sometimes, the faults slip farther than scientists can explain based on their understanding of friction. If flash heating occurs within the faults, it could explain why the two opposing faces slide the way they do, and provoke a better understanding of earthquakes.

In such cases, flash heating would cause minerals to melt and reform, producing an unexpected material around the faults. Some such materials have been identified at the base of long landslides on Earth.

“If something else is going on, like flash heating, or something making [the material] have a lower coefficient of friction, this would affect any models that use the coefficient of friction,” Singer said.

Image courtesy of NASA/JPL/Space Science Institute

This article originally published at Space.com
here

Read more: http://mashable.com/2012/07/30/saturn-moon-landslide/