Europa Might Be Hotter That Previously Thought

When looking for life outside Earth, Jupiter’s moon Europa, with its hypothesized underground ocean, is one of thestrongest candidates in the Solar System. Understanding this fascinating moon could prepare us for future missions there, so scientists are carefully looking at how Europa might have gotten its ocean.

One issue to be considered is how this ocean was kept as a liquid, but a team of astronomers from the U.S. has now suggested that Jupiter’s gravitational attraction has more of a heating effect than thought.Their prediction is an order of magnitude larger than previous estimates, and it better models the condition this (and maybe other) natural satellitesgothrough.

The results, published inEarth and Planetary Science Letters, focused on the ice grains found on Europa. The researchers ranexperiments to recreate the conditions the ice is subjected to, and they discovered that the main source of heat comes from defects in the crystal ice structure, which affects how heat is actually dissipated across the ice shell.

The beauty of this is that once we get the physics right, it becomes wonderfully extrapolative, said co-author Reid Cooper from Brown University in astatement.

Those physics are first order in understanding the thickness of Europas shell. In turn, the thickness of the shell relative to the bulk chemistry of the moon is important in understanding the chemistry of that ocean. And if youre looking for life, then the chemistry of the ocean is a big deal.

The complex surface of Europa is due to the tidal stress the planet is subjected to.NASA/JPL/University of Arizona/University of Colorado

The first indication of Europa being an active world came from images taken by theVoyager probesin 1979. The satellite was notthe smooth, icy ball that was expected, but was instead striped and cracked.

Europa is the sixth moon of Jupiter and orbits the planet in just over three days. It is tidally locked with Jupiter, meaning one face always points towards the gas giant,and it is in orbital resonance with two other moons, Io and Ganymede. The three moons’ periods arewhole integerratios of each other. That is to say, Ganymede’srevolution is twice as long as Europas, which is twice as long as Ios.

This combination of celestial mechanics, added tothe size of Jupiter, stretches and compresses the moons. Io has active volcanoes, and Europa and Ganymede,potentially,liquid oceans.

[Scientists] had expected to see cold, dead places, but right away they were blown away by their striking surfaces, said Christine McCarthy, lead author of the research, in the statement.

There was clearly some sort of tectonic activity things moving around and cracking. There were also places on Europa that look like melt-through or mushy ice.

The only way to have tectonics is through heat, and the only way to have heat in such a small object far away from the Sun is through gravitational force. Perhaps this research will bring us closer to understanding just how Europa’s ocean is maintained.

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Read more: http://www.iflscience.com/space/europa-might-be-hotter-previously-thought

Radiation Exposure Won’t Stop a Manned Mission to Mars

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The risk of radiation exposure is not a show-stopper for a long-term manned mission to Mars, new results from NASA’s Curiosity rover suggest.

A mission consisting of a 180-day cruise to Mars, a 500-day stay on the Red Planet and a 180-day return flight to Earth would expose astronauts to a cumulative radiation dose of about 1.01 sieverts, measurements by Curiosity’s Radiation Assessment Detector (RAD) instrument indicate.

To put that in perspective: The European Space Agency generally limits its astronauts to a total career radiation dose of 1 sievert, which is associated with a 5% increase in lifetime fatal cancer risk.

“It’s certainly a manageable number,” said RAD principal investigator Don Hassler of the Southwest Research Institute in Boulder, Colo., lead author of a study that reports the results Monday in the journal Science.

A 1-sievert dose from radiation on Mars would violate NASA’s current standards, which cap astronauts’ excess-cancer risk at 3 percent. But those guidelines were drawn up with missions to low-Earth orbit in mind, and adjustments to accommodate trips farther afield may be in the offing, Hassler said.

“NASA is working with the National Academies’ Institute of Medicine to evaluate what appropriate limits would be for a deep-space mission, such as a mission to Mars,” Hassler told SPACE.com. “So that’s an exciting activity.”

The new results represent the most complete picture yet of the radiation environment en route to Mars and on the Red Planet’s surface. They incorporate data that RAD gathered during Curiosity’s eight-month cruise through space and the rover’s first 300 days on Mars, where it touched down in August 2012.

The RAD measurements cover two different types of energetic-particle radiation — galactic cosmic rays (GCRs), which are accelerated to incredible speeds by far-off supernova explosions, and solar energetic particles (SEPs), which are blasted into space by storms on our own sun.

RAD’s data show that astronauts exploring the Martian surface would accumulate about 0.64 millisieverts of radiation per day. The dose rate is nearly three times greater during the journey to Mars, at 1.84 millisieverts per day.

But Mars’ radiation environment is dynamic, so Curiosity’s measurements thus far should not be viewed as the final word, Hassler stressed. For example, RAD’s data have been gathered near the peak of the sun’s 11-year activity cycle, a time when the GCR flux is relatively low (because solar plasma tends to scatter galactic cosmic rays).

Curiosity’s radiation measurements should help NASA plan out a manned mission to Mars, which the space agency hopes to pull off by the mid-2030s, Hassler said. And they should also inform the search for signs of past or present life on the Red Planet — another top NASA priority.

For example, the new RAD results suggest that microbial life is unlikely to exist right at the Martian surface, Hassler said. But future missions may not have to drill too deeply underground to find pockets of Mars life, if it ever existed.

“These measurements do tell us that we think it could be viable to find signs of possible extant or past life as shallow as 1 meter deep,” Hassler said.

The new study is one of six papers published in Science Monday that report new results from Curiosity. Most of the other studies present evidence that the rover has found an ancient freshwater lake that could have supported microbial life for tens of thousands, and perhaps millions, of years.

Image: Euclid vanderkroew

This article originally published at Space.com
here

Read more: http://mashable.com/2013/12/09/radiation-mars-curiosity-rover/

Some Martian Lakes Formed Much Later Than We Expected

Today, Mars is a frigid red desert, but there was a time whenthe entire planet had an active water cycle. And according to new research, that period lasted longer than previously thought.

A team of researchers led by Sharon Wilson, from the Smithsonian Institution and the University of Virginia, discovered that lakes and streams continued to flow on the Red Planet for over a billion years after a well-documented era of wet conditions. This finding could be crucial in our understanding of Mars and the potential forlife there.

“We discovered valleys that carried water into lake basins,” said Wilson in a statement. “Several lake basins filled and overflowed, indicating there was a considerable amount of water on the landscape during this time.

The findings, reported in the Journal of Geophysical Research Planets, discuss stream-flows and associated lakes thatcould have been seasonal. They estimated the age of the region by looking at the number of craters and if the water features were there before or after the impacts.

The team estimated that these valleys and lakes were formed between 2and 3billion years ago, long after Mars is believed to have lost its atmosphere and become cold. Although the finding indicates flowing water, this is consistent with a frozen Mars.

“The rate at which water flowed through these valleys is consistent with runoff from melting snow,” Wilson said.”These weren’t rushing rivers. They have simple drainage patterns and did not form deep or complex systems like the ancient valley networks from early Mars.”

These types of valleys appear in vast mid-latitude regions both north and south of the equator. These shallow valleys were part of a global cycle of water rather than a local system.

Our exploration of Mars requires understanding of the geological epochs of the Red Planet and how water shaped this now inhospitable environment. A lot of clues point to a water-rich world in the distant past, and perhaps it was like this long enough for some lifeforms to evolve.

Read more: http://www.iflscience.com/space/some-martian-lakes-formed-much-later-than-we-expected/

How Myths And Tabloids Feed On Anomalies In Science

UNDERSTANDING RESEARCH: What do we actually mean by research and how does it help inform our understanding of things? What if research throws up a result that calls for a new way of thinking? How do we handle that?

There are many misconceptions about science, including how science advances. One half-truth is that unexpected research findings produce crises, leading to new theories that overturn previous scientific knowledge.

Sometimes science progresses in this neat tidy fashion. But not very often. Assuming science is always so simple fuels misunderstanding of science, and provides ammunition to those who attack science, from cosmology to climate change.

Contrary to the myth, most anomalous findings have modest consequences. The vast majority of peculiar findings are usually the result of errors in data, methodology or misunderstanding the implications of existing theories.

Even when anomalies do prompt radical change, it is rare for them to completely upend large swathes of scientific knowledge.

Strange forces and Pioneers
 
In the 1970s, NASA’s Pioneer 10 and 11 spacecraft flew by Jupiter and Saturn before speeding towards interstellar space. As they coasted away from the sun, a strange “Pioneer Anomaly” was observed to be gently slowing the Pioneers. What was going on?

The Pioneer Anomaly has led to hundreds of papers, with many speculating on modified forms of gravity and relativity.

An artist’s impression of Pioneer 10 racing from the Solar System. NASA Ames/Donald Davis

In principle the Pioneers could measure tiny accelerations, as they cruised through space. But they were never designed for precision tests of relativity, nor were they tested (prior to launch) to see if the spacecraft themselves produced tiny accelerations.

After decades of study, it appears the Pioneer anomaly had nothing to do with new physics. The Pioneers generate heat, and thus infrared light (photons), which were subtly pushing on the spacecraft (including via reflections). The Pioneer anomaly, rather than provoking a crisis and new physics, is a triumph of century old physics.

Other anomalies have appeared and disappeared in a similar fashion. But despite this history, media reporting of anomalous results often emphasises how the laws of physics could be overturned, rather than the likelihood of anomalous results disappearing. “Einstein Wrong!” works as click-bait for headlines, but is usually not true.

A personal tale of dark matters

I measure how galaxies grow, and at the end of the 20th century something seemed very wrong with galaxy growth research.

Simulations predicted the biggest galaxies should grow rapidly, as their vast gravity dragged in gas and neighbouring galaxies. In contrast, many observational studies found massive galaxies weren’t growing at all. What happened to all that gravity?

Some speculated that the dark matter paradigm was in trouble. Perhaps galaxies were less massive than people imagined. But instead of prompting radical change, this “crisis” has slowly faded away.

In 2007, I used a vast sample of distant galaxies to detect the slow growth of massive galaxies, and others have mitigated errors that have hampered observational studies of galaxy growth. Observational evidence for dark matter also improved, including cosmic microwave background measurements and the mass distribution within colliding clusters.

As computing power improved and simulations incorporated more complicated astrophysics, including supernovae and black-holes, the growth of simulated galaxies slowed down. So the gulf between simulation and observation closed.

Not so fast big guy! The biggest galaxies don’t grow as quickly as astronomers originally expected. Sloan Digital Sky Survey/Michael Brown

The demise of this anomaly wasn’t as clean as that of the Pioneer anomaly. There were gradual improvements in both simulation and observation, and no single study tied up all the loose ends.

This gradual identification and resolution of anomalous results doesn’t always generate headlines, but it is often how science advances.

The scope for radical change

While most anomalous results fizzle and die, some do spark radical change.

The understanding of the world has been upended when scientific observations and theory have replaced pre-scientific ideas. For example, Galileo’s observations of planets resulted in heliocentric (sun-centred) models of the solar system replacing geocentric (Earth-centred) models.

Truly radical change can also happen when very limited data supports the previous hypothesis. Barry Marshall and Robin Warren won the 2005 Nobel Prize for Medicine for establishing that most stomach ulcers are caused by bacteria, not stress. While the stress causing ulcers had been widely accepted for decades, that hypothesis actually hadn’t been systematically tested.

Einstein’s theories had huge implications for physics, but didn’t upend all previous scientific knowledge. NASA

As a science becomes more mature, with a wealth of supporting data, the implications of anomalous results become more limited. An example of this is Einstein’s general theory of relatively, which was (in part) motivated by odd measurements of the speed of light and the behaviour of Mercury’s orbit.

While general relatively has had huge implications for physics, it didn’t completely upend all previous physics. Maxwell’s equations for electromagnetism are still in use and Newtonian mechanics provides a good approximation of how satellites orbit the Earth.

The apple may have fallen on Newton’s head, but Einstein didn’t make the apple fly away.

Icy anomalies and the tabloids

While anomalous scientific results may seem a curiosity, they are central to public debates about science. To see why, go south!

Temperatures have increased over the past century as a result of increasing atmospheric CO2. The evidence includes (but is not limited to) lab measurements of CO2, measurements of atmospheric CO2, the spectrum of light radiated the Earth, planetary temperatures, and the pattern of temperature increase across the globe.

Increasing sea ice around Antarctica has less implications for global warming that some imagine. Brocken Inaglory/Wikimedia Commons

As a consequence, Arctic sea ice is decreasing, Antarctica and Greenland are losing land ice and sea levels are rising, and yet sea ice area around Antarctica has increased.

The increase in Antarctic sea ice area has been the subject of numerous articles by Andrew Bolt in the Herald-Sun and David Rose in the Daily Mail, among others. Some journalists believe this increase in sea ice is a fundamental flaw in global warming. But what can we conclude from this anomalous result?

The world isn’t getting any colder, so that doesn’t explain the increase in Antarctic sea ice. While simulations didn’t predict the increase in Antarctic sea ice area, they also didn’t predict the unexpectedly rapid decrease in Arctic sea ice either.

Sea ice area depends on air temperature, winds, ocean temperatures and currents, complicating the modelling of sea ice area. A simulation correctly modelling the greenhouse effect can fail to predict sea ice area if it doesn’t correctly model polar winds and oceans. While scientists are aware of this, such nuance is often absent from the tabloid media and blogsphere.

The tabloid media and blogsphere too often falls back on the simplicity of the myth, assuming the anomalous results will upend well-established science. This approach makes for good headlines and political point scoring, but the history tells us that science is very rarely upended in the manner some are wishing for.

This article is part of a series on Understanding Research.

Further reading:
Why research beats anecdote in our search for knowledge
Clearing up confusion between correlation and causation
Where’s the proof in science? There is none
Positives in negative results: when finding ‘nothing’ means something
The risks of blowing your own trumpet too soon on research
How to find the knowns and unknowns in any research
The 10 stuff-ups we all make when interpreting research

The ConversationMichael J. I. Brown receives research funding from the Australian Research Council and Monash University, and has developed space-related titles for Monash University’s MWorld educational app.

The Conversation

Read more: http://www.iflscience.com/editors-blog/how-myths-and-tabloids-feed-anomalies-science

A Dwarf Planet Beyond Neptune Is Bigger Than We Thought

In the last few years, we have started to realize that the dwarf planets beyond Neptuneare just as complex and diverse as the “official” eight planets of the Solar System. Among the dwarf planetsis the unnamed 2007 OR10, a small reddish object currently 13 billion kilometers (8 billion miles) from the Sun. And we’ve now got a better grasp on how big it is.

By combining optical observations from the Kepler observatory and infrared detections from the Herschel satellite, a team of astronomers was able to estimate both its size and its rotational period. The research is published in the Astrophysical Journal.

The team believes2007 OR10rotates on its axis roughly once every 45 hours (although a rotation every 22 hours cannot be ruled out), and by using this information they were able to revise the size estimate to 1,535 kilometers (955 miles) across. If the new measurement is confirmed, it makes 2007 OR10 the third largest trans-Neptunian object.

The new size, which is 250 kilometers higher than previous estimates, has also led the researchers to establish that the dwarf planet is actually darker, based on the fact that the same amount of light we observe is now reflected by a larger area. A bigger size also means higher gravity, indicating that the planet is retaining more complex chemicals, henceits dark reddish color.

“Our revised larger size for 2007 OR10 makes it increasingly likely the planet is covered in volatile ices of methane, carbon monoxide, and nitrogen, which would be easily lost to space by a smaller object,” said Andrs Pl, lead author of the study, in a statement.

“It’s thrilling to tease out details like this about a distant, new world especially since it has such an exceptionally dark and reddish surface for its size.”

Kepler results put2007 OR10 as the largest unnamed body in our Solar System and the third largest ofthedwarf planets.Konkoly Observatory/Andrs Pl, Hungarian Astronomical Association/Ivn der, NASA/JHUAPL/SwR

The new size measurement is certainly interestingand should allow 2007 OR10 to be finally accepted as a dwarf planet, but some are cautious asit has larger uncertainties than any other confirmed dwarf planet. Makemake, another trans-Neptunian object, is only slightly smaller, so the sizemight change with future observations. 2007 OR10 is certainly the largest object in the Solar System without a name, though.

The honor of naming it belongs to the discoverers Meg Schwamb, Mike Brown, and David Rabinowitz. Mike Brown, known for being the discoverer of Eris, the object thatcost Pluto its planetary status, said in a tweet that the naming will happen soon.

“The names of Pluto-sized bodies each tell a story about the characteristics of their respective objects. In the past, we haven’t known enough about 2007 OR10 to give it a name that would do it justice,” said Schwamb. “I think we’re coming to a point where we can give 2007 OR10 its rightful name.”

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Read more: http://www.iflscience.com/space/new-observations-make-2007-or10-largest-unnamed-object-solar-system

Watch Live As Two Astronauts Perform A Spacewalk On The ISS Today

Today at about 8am EDT (1pm BST), you can watch live as two astronauts perform a spacewalk to install a new docking adapter on the International Space Station (ISS).

Known as an extravehicular activity (EVA), the event will see astronauts Jeff Williams and Kate Rubins head outside the station. The goal of the spacewalk is to provide a new parking spot for upcoming private spacecraft from SpaceX and Boeing.

The astronauts will install the Boeing-built International Docking Adapter (IDA) on the stations Harmony module, where the Space Shuttle used to dock. The IDA was transported to the ISS by a SpaceX Dragon vehicle in July a good example already of Boeing and SpaceXs involvement in this multi-national endeavor.

This will be the fourth spacewalk for Williams, and the first for Rubins. The IDA itself is specifically designed for SpaceXs Crew Dragon vehicle and Boeings CST-100 Starliner, both of which hope to start transporting astronauts to the ISS by next year at the earliest. Previous spacewalks prepared the port for this adapter, and now that its on the station, its ready to be installed.

So, check out the live stream below to watch all the action later today. Coverage begins at 6.30am EDT (11.30am BST), with the spacewalk itself starting around 8.05am EDT (1.05pm BST).

Read more: http://www.iflscience.com/space/watch-live-astronauts-spacewalk-iss-today/

65 Digital Media Resources You May Have Missed

65-digital-media-resources-you-may-have-missed-b2e7ac7407

Tablet and Icons

Time passes quickly and change is relentless, particularly in the digital sphere. So, if your busy life kept you away from the Internet this week, there’s plenty you may have missed.

But don’t fret — Mashable, your cyber ally, is here to relieve your digital woes. Our staff tracked down every new gizmo, app, game, website and service they could find. Check them out in our weekly roundup of digital resources, below, and then visit the comments section to let us know which stories you found most interesting.

Editor’s Picks

Social Media

For more social media news and resources, you can follow Mashable‘s social media channel on Twitter and become a fan on Facebook.

Business & Marketing

For more business news and resources, you can follow Mashable‘s business channel on Twitter and become a fan on Facebook.

Tech & Mobile

For more tech news and resources, you can follow Mashable‘s tech channel on Twitter and become a fan on Facebook.

Lifestyle

For more digital lifestyle news and resources, you can follow Mashable‘s lifestyle channel on Twitter and become a fan on Facebook.

Read more: http://mashable.com/2012/10/01/resources-roundup/

Canyon Of Fire On The Sun Is Glorious

Canyon Of Fire On The Sun Is Glorious

The official NASA YouTube channel published this awe-inspiring video of a solar eruption last month. 

A 200,000 mile long magnetic filament exploded from the sun’s atmosphere, leaving behind an apparent canyon of fire. The new video is going viral with over 150,000 views so far.

 

Read more: http://www.viralviralvideos.com/2013/10/25/canyon-of-fire-on-the-sun-is-glorious/