"First, perhaps, it might be best to understand why anyone would want to land on Europa at all. Europa the second of Jupiter's four large satellites is clearly a special place," says Caltech's Mike Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy. "Ever since the time of the Galileo spacecraft nearly 2 decades ago, we have recognized that Europa's fresh icy surface, covered with cracks and ridges and transform faults, is the external signature of a vast internal salty ocean.

NASA will announce new findings about Jupiter's ocean-harboring moon Europa (shown above right along with volcanic moon,  Io) during a news conference at 2 p.m. EDT (1800 GMT) on Monday (Sept. 26). "Astronomers will present results from a unique Europa observation campaign that may be related to the presence of a subsurface ocean on Europa," NASA officials wrote in a media advisory Tuesday (Sept. 20).

In 2013, huge active plumes containing water vapor being released from the surface of Jupiter's moon Europa were discovered shooting up 1200 kilometers. This sensational find was made using the NASA/ESA Hubble Space Telescope. Europa has been a focus of extraterrestrial research for some time, as there were clear indications that it harbors a liquid vast ocean beneath its icy crust. The plumes were not sighted again, however. The involvement of Hubble raises the possibility that Europa's elusive plumes may finally have been spotted again.

The new information comes via NASA's Hubble Space Telescope, agency officials said. We'll post the conference live at dailygalaxy.com via NASA TV

The participants in Monday's briefing are:

Paul Hertz, director of the Astrophysics Division at NASA Headquarters in Washington.

William Sparks, astronomer with the Space Telescope Science Institute in Baltimore.

Britney Schmidt, assistant professor at the School of Earth and Atmospheric Sciences at Georgia Institute of Technology in Atlanta.

Jennifer Wiseman, senior Hubble project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

VIEW MONDAY's CONFERENCE On NASA TV HERE

Caltech astrobiologist Mike Brown regards Europa as one of the solar system's best bets to host alien life. "I know, I know," writes Mike Brown, author of the mikebrownsplanets blog, who specializes in the discovery and study of bodies at the edge of the solar system. "We have all been instructed by Arthur C. Clarke to attempt no landings on Europa. But if you did land on Europa, wouldn't you like to know where to go? If you do, my graduate student, Patrick Fischer, has a paper coming out that you probably want to read."

Brown is best known for his discovery of Eris, the most massive object found in the solar system in 150 years, and the object which led to the debate and eventual demotion of Pluto from a real planet to a dwarf planet. Feature articles about Brown and his work have appeared in the New Yorker, the New York Times, and Discover, and his discoveries have been covered on front pages of countless newspapers worldwide. In 2006 he was named one of Time magazine's 100 Most Influential People.

Here's his fascinating blog post on Jupiter's Europa:

If, on a whim, you climbed down a crack on the surface of Europa and made your way down into the ocean (which, interestingly, might be something you actually could do; though it is more likely you would get stuck and squeezed to death; hard to tell) and then you figured out how to swim down to the rocky bottom something like 100 km below the base of the ice (a depth 10 times greater than the Marianas Trench, by the way) you would instantly be able to answer what to me is one of the most interesting mysteries about Europa. What is happening at the boundary of the rocky core and the ocean? The answer has profound effects on the type of world that Europa ultimately is.

What might be happening down there? The least interesting possibility is that the bottom of the ocean is a stagnant, inactive place: water on top; rock on bottom; a little dissolution of the rock into the water in between, but, otherwise, with not much going on. A world like this wouldn't have much of a source of chemical energy in the ocean, and it's hard to imagine it could support even the most elementary types of life. If you had taken all of that effort to swim all the way to this cold dark dead ocean bottom, you might start to ask yourself whether or not it was even worth it.

The most interesting possibility at least the most interesting possibility that I can think of is that the rocky bottom of the ocean is almost like a miniature Earth, with plate tectonics, continents, deep trenches, and active spreading centers. Think about mid-ocean ridges on Earth, with their black smokers belching scalding nutrient-rich waters into a sea floor teaming with life that is surviving on these chemicals. It doesn't take much of an imagination to picture the same sort of rich chemical soup in Europa's ocean leading to the evolution of some sort of life, living off of the internal energy generated inside of Europa's core. If you're looking for Europa's whales which many of my friends and I often joke that we are this is the world you want to look for them on.

 

Sadly, no one is going to climb down through a crack and then swim to the bottom of Europa's ocean for a long long time, so this is where landing on the surface comes in. If the chemicals that are dissolved inside of the ocean could somehow make it to the surface, we could learn a lot about what is going on deep inside of Europa just by analyzing a little a sample of the surface.

OK,then, let's go land! But where? You probably only get one shot at a lander, and you probably don't get to move once you land, so you had better pick the right spot. The announcement a couple of years ago, that plumes of water jetting from Europa's south pole had been discovered by the Hubble Space Telescope, seemed to have answered the question: land at the pole, and wait for plumes to rain down upon you (or, perhaps even more easily, fly through the plumes and collect samples without even landing!).

The bad news, however, is that the plumes now appear to be elusive at best and non-existent at worst. Since their initial detection no one has been able to see them again. Are they (very) sporadic? Was the initial detection an unfortunate spurious signal that was misinterpreted? No one yet knows, but no one today is going to count on plumes for measuring the chemical composition of the ocean.

Luckily, our new paper shows that we don't need plumes to sample the interior, and we even conveniently point out a potential landing area that is large enough to easily target with your favorite lander.

First, how do you find a landing site? What we are actually doing is simply mapping the composition of the ices across the surface of Europa. Such mapping has been going since the time of the Galileo mission, but with modern telescopic instruments and high spatial resolution adaptive optics systems on large telescope on Earth, we can do a better job of making global scale maps than the Galileo spacecraft ever could. In the earlier Galileo mapping efforts and in our own early analyses of our own data, we concentrated mainly on dividing the surface of Europa into an ice component and a non-ice component and then trying to figure out what the non-ice component was.

Like the earlier Galileo analyses, we found that the dominant non-ice component is sulfuric acid that is created when sulfur (ultimately derived from volcanoes on Io!) bombards the water ice on the surface of Europa. We also found, though, that some of the non-ice material was magnesium sulfate Epsom salts, in fact which we suggested indicated a magnesium source coming from inside of Europa's ocean that then mixes with the incoming sulfur.

Patrick Fischer, in his new analysis, decided to take these ideas one step further. He wanted to know if there is anything else on the surface of Europa besides just the water ice and the sulfur products. To do so, he took the spectra of nearly 1600 separate spots on the surface of Europa and started looking for anything unusual that stood out. The answer was…… maybe. Staring at that many spectra you're bound to find something to catch your eye. He needed a more rigorous method to group the spectra together, and eventually he developed a very clever new mathematical tool which allows you to take an arbitrary collection of spectra and automatically, with no preconceived human biases, classify them into an arbitrary number of distinct spectra, and present maps of where those materials are present on the surface.

When he asked the tool to give him to find the two most distinct spectra on the surface of Europa, he reproduced the ice plus sulfur products distributions that had been known for decades. When he asked for a third distinct spectrum, though, a large region on the surface of Europa suddenly popped out as being composed of material unlike the ice or sulfur products of the previous map. Staring back and forth between the composition map he had just made and a geological map of the surface of Europa, he was startled to realize that he had nearly precisely mapped out one of the largest regions of what is called “chaos terrain” on Europa. (NASA image below)

 

Mapping the composition of the surface of Europa has shown that a few large areas have large concentrations of what are thought to be salts. These salts are systematically located in the recently resurfaced "chaos regions." One such region, named Western Powys Regio, has the highest concentration of these materials presumably derived from the internal ocean, and would make an ideal landing location for a Europa surface probe.

On Europa, "chaos terrains" are regions where the icy surface appears to have been broken apart (NASA image above) , moved around, and frozen back together. Observations by Caltech graduate student Patrick Fischer and colleagues show that these regions have a composition distinct from the rest of the surface which seems to reflect the composition of the vast ocean under the crust of Europa.

Chaos terrain was noticed early on in the Galileo mission as regions which look like the surface of Europa has become cracked and jumbled and intriguingly perhaps even melted in recent times. If you had to vote for a location on Europa where ocean water had recently melted through and dumped its chemicals on the surface, you would vote for chaos terrain. And now Patrick had found that on large regional scales chaos terrain has a different composition than the rest of the surface of Europa!

And what do the spectra tell us that the unique composition of this chaos terrain is? Sadly, we can't yet tell. To date, we have not found unique compositional indicators in the spectra of this region, though our search is ongoing. Our best bet, though is that we are looking at salts left over after a large amount of ocean water flowed out on to the surface and then evaporated away. The best analogy would be to large salt flats in desert regions of the world. Just like these salt flats, the chemical composition of the salt reflects whatever materials were dissolved in the water before it evaporated. On the Earth, salt flats can contain any number of exotic salts, depending on the surrounding rock chemistry. On Europa, the salts will tell about the rock chemistry, too, though the rock is the material far below at the base of the ocean.

We think, then, that we have found a giant salty patch on the surface of Europa, and very likely the region of most recent resurfacing and undisturbed chemistry. I have tried very hard to get Patrick to call this salty patch Margaritaville, but he does not think that graduate students are quite established enough to make jokes like that. I'll make it for him, though. And I will tell you: attempt a landing there!

Margaritaville will not only have salts that tell you about the rock-ocean interaction, but it will also have samples of everything else that the ocean has to offer. Is there organic chemistry taking place in the oceans? Look in Margaritaville. Carbonates? Margaritaville. Microbes? Definitely Margaritaville. All of these are best searched for with the types of instruments currently roving around on Mars, where you grab a sample, put it into a machine, and read back out the chemical composition.

But don't forget to bring the cameras along, too, just to see what else is lying around. The jumbled and exotic icy terrain is bound to be a spectacular site up close. You might get lucky and see a plume shooting off into the sky in the distance. And maybe, just maybe you'll even find a few whale bones lying around.

The Daily Galaxy via NASA, Caltech and mikebrownsplanets.com

Image top of page, courtesy of K. Retherford, Southwest Research Institute and NASA

Related articles

 

Related articles

Hubble --"Largest Moon in Our Solar System Harbors a Buried Ocean 100 Kilometers Deep" (Weekend Feature)

Jupiter's Ganymede: Hubble Reveals a Buried Ocean 100 Kilometers Deep

Hubble Captures Mysterious Rebirth of a Star --"The 1st Ever Observed"

Image of the Day --Rare Conjunction of Jupiter's Three Largest Moons

The Quest to Discover Proxima B --Closest Habitable Planet to Our Solar System (VIEW/European Southern Observatory Video) - The Daily Galaxy --Great Discoveries Channel

 

 

The breakthrough relies on ‘spooky' quantum-physics phenomenon of entanglement, dubbed by Albert Einstein as “spooky action at a distance." Until recently, the idea of quantum radar had remained largely confined to science fiction. China Electronics Technology Group Corporation (CETC), one of the “Top 10” military industry groups controlled directly by the central government, stunned physicists around the world this week when it announced it's the new radar system's entangled photons had detected targets 100 kilometers away in a recent field test.

America's Defense Advanced Research Projects Agency has reportedly funded similar research and military suppliers such as Lockheed Martin are also developing quantum radar systems for combat purposes, according to media reports, but the progress of those military projects remains unknown.

In a statement posted on its website on Sunday, CETC said China's first “single-photon quantum radar system” had “important military application values” because it used entangled photons to identify objects “invisible” to conventional radar systems.

Nanjing University physicist Professor Ma Xiaosong, who has studied quantum radar, said he had “not seen anything like this in an open report. The effective range reported by the international research community falls far below 100km,” he said. Elsewhere, a military radar researcher at a university in northwestern China said the actual range of the new radar could be even greater than that announced by CETC.“The figure in declassified documents is usually a tuned-down version of the real [performance],” he said. “The announcement has gone viral.”

 The image below shows a  U.S. Air Force B-2 Spirit Strategic stealth bomber flying over the Pacific Ocean.

 

 

A quantum radar, generating a large number of entangled photon pairs and shooting one twin into the air, would be capable of receiving critical information about a target, including its shape, location, speed, temperature and even the chemical composition of its paint, from returning photons.

In theory, a quantum radar could detect a target's composition, heading and speed even if managed to retrieve just one returning photon. It would be able to fish out the returning photon from the background noise because the link the photon shared with its twin would facilitate identification.

The photons had to maintain certain conditions known as quantum states such as upward or downward spin to remain entangled. But Ma said the quantum states could be lost due to disturbances in the environment, a phenomenon known as “decoherence”, which increased the risk of entanglement loss as the photons traveled through the air, thus limiting the effective range of quantum radar.

The CETC breakthrough benefited largely from the recent rapid development of single-photon detectors, which allowed researchers to capture returning photons with a high degree of efficiency.

The Daily Galaxy via SCMP Read More Here

Related articles

Today's 'Galaxy' Insight --The Origin of Spacetime

Universe of Quantum Strangeness --The 'Reality' Boundary Grows Foggier

Black Hole Collisions --"Astronomers 'Hear' Them Via Gravity Signals"

 

“We call it the ‘globular cluster opportunity,'” says Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics (CfA). “A globular cluster might be the first place in which intelligent life is identified in our galaxy. Sending a broadcast between the stars wouldn't take any longer than a letter from the U.S. to Europe in the 18th century. “Interstellar travel would take less time too. The Voyager probes are 100 billion miles from Earth, or one-tenth as far as it would take to reach the closest star if we lived in a globular cluster. That means sending an interstellar probe is something a civilization at our technological level could do in a globular cluster,” she adds.

Globular star clusters are amazing in almost every way. They're densely packed, holding a million stars in a ball only about 100 light-years across on average. They're old, dating back almost to the birth of the Milky Way. And according to new research, they also could be extraordinarily good places to look for space-faring civilizations.

The Milky Way hosts about 150 globular clusters, most of them orbiting in the galactic outskirts. They formed about 10 billion years ago on average. As a result, their stars contain fewer of the heavy elements needed to construct planets, since those elements (like iron and silicon) must be created in earlier generations of stars. Some scientists have argued that this makes globular cluster stars less likely to host planets. In fact, only one planet has been found in a globular cluster to date.  The ESO image above shows 47 Tucanae the second most luminous globular cluster in the Milky Way, after Omega Centauri.

 

However, Di Stefano and her colleague Alak Ray of the Tata Institute of Fundamental Research in Mumbai, India, argue that this view is too pessimistic. Exoplanets have been found around stars only one-tenth as metal-rich as our sun. And while Jupiter-sized planets are found preferentially around stars containing higher levels of heavy elements, research finds that smaller, Earth-sized planets show no such preference.

“It's premature to say there are no planets in globular clusters,” states Ray.

Another concern is that a globular cluster's crowded environment would threaten any planets that do form. A neighboring star could wander too close and gravitationally disrupt a planetary system, flinging worlds into icy interstellar space.

However, a star's habitable zone — the distance at which a planet would be warm enough for liquid water — varies depending on the star. While brighter stars have more distant habitable zones, planets orbiting dimmer stars would have to huddle much closer. Brighter stars also live shorter lives, and since globular clusters are old, those stars have died out. The predominant stars in globular clusters are faint, long-lived red dwarfs. Any potentially habitable planets they host would orbit nearby and be relatively safe from stellar interactions.

“Once planets form, they can survive for long periods of time, even longer than the current age of the universe,” explains Di Stefano.

So if habitable planets can form in globular clusters and survive for billions of years, what are the consequences for life should it evolve? Life would have ample time to become increasingly complex, and even potentially develop intelligence.

 

 

Such a civilization would enjoy a very different environment than our own. The nearest star to our solar system is four light-years, or 24 trillion miles, away. In contrast, the nearest star within a globular cluster could be about 20 times closer — just 1 trillion miles away. This would make interstellar communication and exploration significantly easier.

The closest globular cluster to Earth is still several thousand light-years away, making it difficult to find planets, particularly in a cluster's crowded core. But it could be possible to detect transiting planets on the outskirts of globular clusters. Astronomers might even spot free-floating planets through gravitational lensing, in which the planet's gravity magnifies light from a background star.

A more intriguing idea might be to target globular clusters with SETI search methods, looking for radio or laser broadcasts. The concept has a long history: In 1974 astronomer Frank Drake used the Arecibo radio telescope to broadcast the first deliberate message from Earth to outer space. It was directed at the globular cluster Messier 13 (M13).

The Daily Galaxy via Harvard University

Image credits: uoregon.edu 

Related articles

Thirty Percent of Stars Have Migrated Across the Milky Way --"Was Our Sun One?"

Star Streams of the Milky Way --"Trace of the Orbits of Ancient Globular Clusters"

Ancient Milky-Way Star Cluster Fossil Revealed --"Unlike Any Other Known"

Milky Way Found to Be Much Larger Than Thought --Extending Width 50% to 150,000 Light Years!

Phantoms of the Milky Way --"Galactic Quakes Reveal Invisible Starless Galaxies Orbiting Our Galaxy"

 

 

A team led by Case Western Reserve University researchers has found a significant new relationship in spiral and irregular galaxies: the acceleration observed in rotation curves tightly correlates with the gravitational acceleration expected from the visible mass only. In a paper accepted for publication by the journal Physical Review Letters and posted on the preprint website arXiv, the astronomers argue that the relation they've found is tantamount to a new natural law.

"The natural inference is that this law stems from a universal force such as a modification of gravity like MOND, the hypothesis of Modified Newtonian Dynamics proposed by Israeli physicist Moti Milgrom," says Stacy McGaugh, chair of the Department of Astronomy at Case Western Reserve. "But it could also be something in the nature of dark matter like the superfluid dark matter proposed by Justin Khoury," McGaugh said. "Most importantly, whatever theory you want to build has to reproduce this."

"The standard model of cosmology is remarkably successful at explaining just about everything we observe in the universe," said Arthur Kosowsky, professor of physics and astronomy at the University of Pittsburgh, who was not involved but reviewed the research."But if there is a single observation which keeps me awake at night worrying that we might have something essentially wrong, this is it."

In spiral galaxies such as NGC 6946 (shown above), researchers found that a 1-to-1 relationship between the distribution of stars plus gas and the acceleration caused by gravity exists. In the late 1970s, astronomers Vera Rubin and Albert Bosma independently found that spiral galaxies rotate at a nearly constant speed: the velocity of stars and gas inside a galaxy does not decrease with radius, as one would expect from Newton's laws and the distribution of visible matter, but remains approximately constant. Such 'flat rotation curves' are generally attributed to invisible, dark matter surrounding galaxies and providing additional gravitational attraction.

"If you measure the distribution of star light, you know the rotation curve, and vice versa," said McGaugh, lead author of the research. "The finding is consistent among 153 spiral and irregular galaxies, ranging from giant to dwarf, those with massive central bulges or none at all. It is also consistent among those galaxies comprised of mostly stars or mostly gas.

An astrophysicist who reviewed the study said the findings may lead to a new understanding of internal dynamics of galaxies.

"Galaxy rotation curves have traditionally been explained via an ad hoc hypothesis: that galaxies are surrounded by dark matter," said David Merritt, professor of physics and astronomy at the Rochester Institute of Technology, who was not involved in the research. "The relation discovered by McGaugh et al. is a serious, and possibly fatal, challenge to this hypothesis, since it shows that rotation curves are precisely determined by the distribution of the normal matter alone. Nothing in the standard cosmological model predicts this, and it is almost impossible to imagine how that model could be modified to explain it, without discarding the dark matter hypothesis completely."

McGaugh and Schombert have been working on this research for a decade and with Lelli the last three years. Near-infrared images collected by NASA's Spitzer Space Telescope during the last five years allowed them to establish the relation and that it persists for all 153 galaxies.

The key is that near-infrared light emitted by stars is far more reliable than optical-light for converting light to mass, Lelli said.

The researchers plotted the radial acceleration observed in rotation curves published by a host of astronomers over the last 30 years against the acceleration predicted from the observed distribution of ordinary matter now in the Spitzer Photometry & Accurate Rotation Curves database McGaugh's team created. The two measurements showed a single, extremely tight correlation, even when dark matter is supposed to dominate the gravity.

"There is no intrinsic scatter, which is how far the data differ on average from the mean when plotted on a graph," McGaugh said. "What little scatter is found is consistent with stellar mass-to-light ratios that vary a little from galaxy to galaxy."

Lelli compared the relation to a long-used natural law. "It's like Kepler's third law for the solar system: if you measure the distance of each planet from the sun, you get the orbital period, or vice versa" he said. "Here we have something similar for galaxies, with about 3,000 data points."

"In our case, we find a relation between what you see in normal matter in galaxies and what you get in their gravity," McGaugh said. "This is important because it is telling us something fundamental about how galaxies work."

Kosowsky said McGaugh and collaborators have steadily refined the spiral galaxy scaling relation for years and called this latest work a significant advance, reducing uncertainty in the mass in normal matter by exploiting infrared observations.

"The result is a scaling relation in the data with no adjustable parameters," Kosowky said. "Throughout the history of physics, unexplained regularities in data have often pointed the way towards new discoveries."

McGaugh and his team are not pressing any theoretical interpretation of their empirical relation at this point.

The Daily Galaxy via Case Western Reserve University

Related articles

Friday's 'Galaxy' Insight --"Why the Universe Exists"

"The Observed Alien Planets in the Milky Way" --A NASA Image of the Kepler Mission Discoveries

Planetary "Doomsday" Zones Mapped - The Daily Galaxy --Great Discoveries Channel

NASA: "X-Rays Light Up Sun-Like Coronas of Black Holes"

In a recent experiment, a Swedish scientist, Fredrik Lanner, a developmental biologist at the Karolinska Institute in Stockholm, attempted to modify the genes of a human embryos injecting a gene-editing tool known as CRISPR-Cas9 into carefully thawed five human embryos donated by couples who had gone through in vitro fertilization (IVF). One did not survive the cooling and thawing process, while another one was severely damaged while being injected. The remaining three embryos, which were two-days old when they were injected, survived in good shape, with one of them dividing immediately after being injected.

Scientists have viewed modifying a human embryo as over the line for safety and ethical concerns. The fear is that Lanner's work could open the door to others attempting to use genetically modified embryos to make babies. One mistake could introduce a new disease in the human gene pool that can be inherited by future generations. Scientists are also concerned on the possibility of "designer babies," where parents could choose traits they want for their babies.

Fredrik Lanner (right) of the Karolinska Institute in Stockholm and his student Alvaro Plaza Reyes examine a magnified image of an human embryo that they used to attempt to create genetically modified healthy human embryos. (Credit: Rob Stein/NPR)

 

 

Making changes to the DNA in human embryos could accidentally introduce an error into the human gene pool, inadvertently creating a new disease that would be passed down for generations, critics say.

However, Lanner clarified that he is doing his experiment in order to further understand how genes regulate early embryonic development. He noted that his work could one day be used by scientists to develop new treatments for miscarriage and infertility. Additionally, Lanner also hopes to open new ways to use embryonic stem cells to treat many diseases.

"If we can understand how these early cells are regulated in the actual embryo, this knowledge will help us in the future to treat patients with diabetes, or Parkinson, or different types of blindness and other diseases," explained Lanner, a developmental biologist at the Karolinska Institute in Stockholm, in an exclusive interview with National Public Radio. "That's another exciting area of research."

The Daily Galaxy via CBS News and NPR

Image at top of page: sculpture by Antony Gormley

Related articles

Today's 'Galaxy' Insight --"Our Weird Universe"

"Your Inner Jellyfish" --Origin of Electrical Communication in Human Brain Traced Back 600 Million Years

Origins of Life On Earth & Beyond --"From Matter to Living Biology" (Weekend Feature)