Rosetta Comet Outburst Captured (NASA)

The European Space Agency's Rosetta spacecraft has been witnessing growing activity from comet 67P/Churyumov-Gerasimenko as the comet approaches perihelion (its closest point to the sun during its orbit). On July 29, while the spacecraft orbited at a distance of 116 miles (186 kilometers) from the comet, it observed the most dramatic outburst to date. Early science results collected during the outburst came from several instruments aboard Rosetta, including the Double Focusing Mass Spectrometer (DFMS), which uses NASA-built electronics. The DFMS is part of the spacecraft's Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument.
When the outburst occurred, the spectrometer recorded dramatic changes in the composition of outpouring gases from the comet when compared to measurements made two days earlier. As a result of the outburst, the amount of carbon dioxide increased by a factor of two, methane by four, and hydrogen sulfide by seven, while the amount of water stayed almost constant.
"This first quick look at our measurements after the outburst is fascinating," said Kathrin Altwegg, principal investigator for the ROSINA instrument from the University of Bern, Switzerland. "We also see hints of heavy organic material after the outburst that might be related to the ejected dust.
"But while it is tempting to think that we are detecting material that may have been freed from beneath the comet's surface, it is too early to say for certain that this is the case."
A sequence of images taken by Rosetta's scientific camera OSIRIS shows the sudden onset of a well-defined, jet-like feature emerging from the side of the comet's neck. The jet, the brightest seen to date, was first recorded in an image taken at 6:24 a.m. PDT (9:24 a.m. EDT, 13:24 GMT) on July 29, but not in an image taken 18 minutes earlier. The jet then faded significantly in an image captured 18 minutes later. The OSIRIS camera team estimates the material in the jet was traveling at 33 feet per second (10 meters per second), at least.
A composite of the three images taken by Rosetta's OSIRIS is online at:
http://rosetta.jpl.nasa.gov
On Thursday, Aug. 13, the comet and Rosetta will be 116 million miles (186 million kilometers) from the sun -- the closest to the sun they will be in their 6.5-year orbit. In recent months, the increasing solar energy has been warming the comet's frozen ices -- turning them to gas -- which pours out into space, dragging dust along with it. The period around perihelion is scientifically very important, as the intensity of the sunlight increases and parts of the comet previously cast in years of darkness are flooded with sunlight. The comet's general activity is expected to peak in the weeks following perihelion.
Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander, Philae, obtained the first images taken from a comet's surface and will provide analysis of the comet's possible primordial composition. Rosetta is the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations are helping scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even

NASA Mars Rover Moves Onward After 'Marias Pass' Studies (NASA)

NASA's Curiosity Mars rover is driving toward the southwest after departing a region where for several weeks it investigated a geological contact zone and rocks that are unexpectedly high in silica and hydrogen content. The hydrogen indicates water bound to minerals in the ground.
In this "Marias Pass" region, Curiosity successfully used its drill to sample a rock target called "Buckskin" and then used the camera on its robotic arm for multiple images to be stitched into a self-portrait at the drilling site. The new Curiosity selfie from a dramatically low angle is online at:
http://www.jpl.nasa.gov/spaceimages/details.php?id=pia19808
The rover finished activities in Marias Pass on Aug. 12 and headed onward up Mount Sharp, the layered mountain it reached in September 2014. In drives on Aug. 12, 13, 14 and 18, it progressed 433 feet (132 meters), bringing Curiosity's total odometry since its August 2012 landing to 6.9 miles (11.1 kilometers).
Curiosity is carrying with it some of the sample powder drilled from Buckskin. The rover's internal laboratories are analyzing the material. The mission's science team members seek to understand why this area bears rocks with significantly higher levels of silica and hydrogen than other areas the rover has traversed.
Silica, monitored with Curiosity's laser-firing Chemistry and Camera (ChemCam) instrument, is a rock-forming chemical containing silicon and oxygen, commonly found on Earth as quartz. Hydrogen in the ground beneath the rover is monitored by the rover's Dynamic Albedo of Neutrons (DAN) instrument. It has been detected at low levels everywhere Curiosity has driven and is interpreted as the hydrogen in water molecules or hydroxyl ions bound within or absorbed onto minerals in the rocks and soil.
"The ground about 1 meter beneath the rover in this area holds three or four times as much water as the ground anywhere else Curiosity has driven during its three years on Mars," said DAN Principal Investigator Igor Mitrofanov of Space Research Institute, Moscow. DAN first detected the unexpectedly high level of hydrogen using its passive mode. Later, the rover drove back over the area using DAN in active mode, in which the instrument shoots neutrons into the ground and detects those that bounce off the subsurface, but preferentially interacting with hydrogen. The measurements confirmed hydrated material covered by a thin layer of drier material.
Curiosity initially noted the area with high silica and hydrogen on May 21 while climbing to a site where two types of sedimentary bedrock lie in contact with each other. Such contact zones can hold clues about ancient changes in environment, from conditions that produced the older rock type to conditions that produced the younger one. This contact is the lure that led the rover team to choose Marias Pass as a route toward higher layers of Mount Sharp. Pale mudstone, like bedrock the mission examined for the first several months after reaching Mount Sharp at an area called "Pahrump Hills," forms one side of the contact. The overlying side is darker, finely bedded sandstone.
Curiosity examined the Marias Pass contact zone closely with instruments mounted on its mast and arm. The unusual levels of silica and hydrogen in rocks passed during the climb prompted a choice to backtrack to examine that area and acquire a drilled sample.
Buckskin was the first rock drilled by Curiosity since an electrical circuit in the drill's percussion mechanism exhibited a small, transient short circuit in February during transfer of sample powder from the third target drilled in the Pahrump Hills area.
"We were pleased to see no repeat of the short circuit during the Buckskin drilling and sample transfer," said Steven Lee, deputy project manager for Curiosity at NASA's Jet Propulsion Laboratory, Pasadena, California. "It could come back, but we have made changes in fault protection to continue safely drilling even in the presence of small shorts. We also improved drill percuss circuit telemetry to gain more diagnostic information from any future occurrences."
Curiosity reached the base of Mount Sharp after two years of fruitfully investigating outcrops closer to its landing site and trekking to the mountain. The main mission objective now is to examine layers of lower Mount Sharp for ancient habitable environments and evidence about how early Mars environments evolved from wetter to drier conditions

Colorful Calendar Celebrates 12th Anniversary of NASA's Spitzer (NASA)

Celebrate the 12th anniversary of NASA's Spitzer Space Telescope with a new digital calendar showcasing some of the mission's most notable discoveries and popular cosmic eye candy.
The digital calendar is online at:
http://www.jpl.nasa.gov/images/spitzer/20150820/Spitzer12thAnniversaryCalendar.pdf
The calendar follows the life of the mission, with each month highlighting top infrared images and discoveries from successive years -- everything from a dying star resembling the eye of a monster to a star-studded, swirling galaxy. The final month includes a brand new image of the glittery star-making factory known as the Monkey Head nebula.
"You can't fully represent Spitzer's scientific bounty in only 12 images," said Michael Werner of NASA's Jet Propulsion Laboratory in Pasadena, California, the mission's project scientist and a Spitzer team member since 1977. "But these gems demonstrate Spitzer's unique perspectives on both the nearest, and the most distant, objects in the universe."
Spitzer, which launched into space on August 25, 2003, from Cape Canaveral, Florida, is still going strong. It continues to use its ultra-sensitive infrared vision to probe asteroids, comets, exoplanets (planets outside our solar system) and some of the farthest known galaxies. Recently, Spitzer helped discover the closest known rocky exoplanet to us, named HD219134b, at 21 light-years away.
In fact, Spitzer's exoplanet studies continue to surprise the astronomy community. The telescope wasn't originally designed to study exoplanets, but as luck -- and some creative engineering -- would have it, Spitzer has turned out to be a critical tool in the field, probing the climates and compositions of these exotic worlds. This pioneering work began in 2005, when Spitzer became the first telescope to detect light from an exoplanet.
Other top discoveries from the mission so far include:
-- Recipe for "comet soup." Spitzer observed the aftermath of the collision between NASA's Deep Impact spacecraft and comet Tempel 1, finding that cometary material in our own solar system resembles that around nearby stars.
-- The largest known ring around Saturn, a wispy, fine structure with 300 times the diameter of Saturn.
-- First exoplanet weather map of temperature variations over the surface of a gas exoplanet. Results suggested the presence of fierce winds.
-- Asteroid and planetary smashups. Spitzer has found evidence for several rocky collisions in other solar systems, including one thought to involve two large asteroids.
-- The hidden lairs of newborn stars. Spitzer's infrared images have provided unprecedented views into the hidden cradles where young stars grow up, revolutionizing our understanding of stellar birth.
-- Buckyballs in space. Buckyballs are soccer-ball-shaped carbon molecules that have important technological applications on Earth.
-- One of the most remote planets known, lying about 13,000 light-years away, deep within our galaxy. Spitzer continues to help in the search for exoplanets using a state-of-the-art method called microlensing.
-- Massive clusters of galaxies. Spitzer has identified many more distant galaxy clusters than were previously known.
-- "Big baby" galaxies. Spitzer and Hubble has found remote galaxies that were much more massive and mature than expected.

Cassini's Final Breathtaking Close Views of Dione (NASA)

 

 

A pockmarked, icy landscape looms beneath NASA's Cassini spacecraft in new images of Saturn's moon Dione taken during the mission's last close approach to the small, icy world. Two of the new images show the surface of Dione at the best resolution ever.
Cassini passed 295 miles (474 kilometers) above Dione's surface at 11:33 a.m. PDT (2:33 p.m. EDT) on Aug. 17. This was the fifth close encounter with Dione during Cassini's long tour at Saturn. The mission's closest-ever flyby of Dione was in Dec. 2011, at a distance of 60 miles (100 kilometers).
"I am moved, as I know everyone else is, looking at these exquisite images of Dione's surface and crescent, and knowing that they are the last we will see of this far-off world for a very long time to come," said Carolyn Porco, Cassini imaging team lead at the Space Science Institute, Boulder, Colorado. "Right down to the last, Cassini has faithfully delivered another extraordinary set of riches. How lucky we have been."
Raw, unprocessed images from the flyby are available at:
http://saturn.jpl.nasa.gov/mission/flybys/dione20150817/
The main scientific focus of this flyby was gravity science, not imaging. This made capturing the images tricky, as Cassini's camera was not controlling where the spacecraft pointed.
"We had just enough time to snap a few images, giving us nice, high resolution looks at the surface," said Tilmann Denk, a Cassini participating scientist at Freie University in Berlin. "We were able to make use of reflected sunlight from Saturn as an additional light source, which revealed details in the shadows of some of the images."
Cassini scientists will study data from the gravity science experiment and magnetosphere and plasma science instruments over the next few months as they look for clues about Dione's interior structure and processes affecting its surface.
Only a handful of close flybys of Saturn's large, icy moons remain for Cassini. The spacecraft is scheduled to make three approaches to the geologically active moon Enceladus on Oct. 14 and 28, and Dec. 19. During the Oct. 28 flyby, the spacecraft will come dizzyingly close to Enceladus, passing a mere 30 miles (49 kilometers) from the surface. Cassini will make its deepest-ever dive through the moon's plume of icy spray at this time, collecting valuable data about what's going on beneath the surface. The December Enceladus encounter will be Cassini's final close pass by that moon, at an altitude of 3,106 miles (4,999 kilometers).
After December, and through the mission's conclusion in late 2017, there are a handful of distant flybys planned for Saturn's large, icy moons at ranges of less than about 30,000 miles (50,000 kilometers). Cassini will, however, make nearly two dozen passes by a menagerie of Saturn's small, irregularly shaped moons -- including Daphnis, Telesto, Epimetheus and Aegaeon -- at similar distances during this time. These passes will provide some of Cassini's best-ever views of the little moons.
During the mission's final year -- called its Grand Finale -- Cassini will repeatedly dive through the space between Saturn and its rings.

Tiny fountain of atoms sparks big insights into dark energy

It's a study in contrasts. For more than a decade, physicists have been puzzling over dark energy, the mysterious stuff that’s blowing space apart and has been detected only by studying the universe on the largest scales. Now, researchers have probed its properties using about the smallest tools available—atoms falling freely in a vacuum chamber. The experiment, reported today in Science, doesn't  reveal what dark energy is, but it helps nail down what it isn't. In particular, it narrows the prospects for one popular idea: that dark energy resides in hypothesized "chameleon particles" hiding in plain sight.

"I find it exciting to be able to use laboratory-scale experiments to test such ideas," says Amol Upadhye, a theoretical physicist at the University of Wisconsin, Madison, who was not involved in the work. The test doesn’t entirely rule out chameleons, he says, but future improvements might put the idea to the ultimate test.

The discovery of dark energy rocked physics and cosmology. Scientists thought the expansion of the universe was slowing, as the galaxies tugged on one another with their gravity and counteracted the expansion that began with the big bang. However, in 1998, two teams of cosmologists showed that in fact the expansion is accelerating by studying stellar explosions called supernovae. The result has been bolstered by analyses of galaxy clusters, the afterglow of the big bang (the cosmic microwave background), and other cosmological phenomena. Physicists attribute the acceleration to some sort of space-stretching dark energy.

But what is dark energy? There are two possibilities. It could be energy hidden in the vacuum of empty space itself—a cosmological constant, as Albert Einstein hypothesized in 1917. Or it could be a quantum field that fills space and blows it up like a balloon. Both alternatives have problems. Given the standard model of particle physics, theorists can calculate what the cosmological constant should be, and they get a value vastly too big to explain the relatively modest acceleration—suggesting some unknown physics just zeroes it out. On the other hand, the presence of a quantum field would affect things like the orbits of the planets in the solar system—but dark energy doesn’t seem to.

That's where chameleon particles come in. The hypothetical particles would make up just such a quantum field, but they would interact with matter in a way that would make the field vanish wherever the density of matter was high. Thus the field would exert no noticeable effect on things like planets. "The chameleon, like many other theoretical ideas, has a small probability of being there," says Justin Khoury, a theoretical cosmologist at the University of Pennsylvania and co-inventor of the concept. "Nonetheless we should test it if we can."

That's just what Khoury, Holger Müller, an atomic physicist at the University of California, Berkeley, and colleagues have done. To search for a chameleon field, they studied the interactions between an aluminum sphere 9.5 millimeters in diameter and a puff of 10 million ultracold cesium atoms within a vacuum chamber. If there were a chameleon field within the vacuum, then the sphere would squash it. And like a bowling ball on a trampoline, the sphere would bend the field just outside its surface, causing the field’s strength to taper to zero. The cloud of atoms would slide down the sloping field, experiencing a short-range force toward the sphere. Crucially, the cloud itself was not dense enough to suppress the field and spoil the effect. "In the simplest terms, we're looking for a funny force between the sphere and the atoms," Müller says.

That force would come in addition to the pull of Earth's gravity. So, the researchers repeated the experiment in two different configurations. In one, they dropped the atoms from 8.8 millimeters above the sphere, close enough for the sloping chameleon field to exert a force. They used an exquisitely sensitive technique called atom interferometry to measure the cesium atoms’ acceleration as they fell for about 20 milliseconds (see figure). In the other configuration, they dropped the atoms well to the side of the sphere, where the chameleon field should have been uniform and produced no force. So, if there were a chameleon field, the atoms would accelerate downward faster when dropped above the sphere. In fact, in both configurations, the atoms accelerated at the same rate to within a precision of 1 part in 1 million.

Curiously, neither Müller nor Khoury thought up the experiment. Instead, it was proposed by Clare Burrage and Edmund Copeland of the University of Nottingham in the United Kingdom and Edward Hinds of Imperial College London, in a paper they posted to the arXiv preprint server a year ago. "Of course I was disappointed that they did it before us," Hinds says, "but they already had a suitable apparatus, while we have had to build an experiment specifically for the purpose."

At its current precision, the experiment rules out only chameleons whose interaction with matter—the thing that makes the field go away where the matter density is high—is much stronger than gravity, Khoury says. Those that interact with matter more weakly are still viable, he says. Müller says that his team aims to improve the precision of their experiment to 1 part in 1 billion, which should put the chameleon to the ultimate test. Hinds is trying to beat Müller to that goal. And even if the chameleon concept dies, there are other ways to hide a quantum field that would produce dark energy

U.S. neutrino experiments first result tantalizes (AAAS)

The United States' newest neutrino experiment has collected only one-thirteenth of its expected data, but early results suggest it could achieve its main goal: ranking the mysterious particles by their weights. Neutrinos are nearly massless and barely interact with other matter; they come in three "flavors"—electron, muon, and tau—that can morph into one another. Two of the neutrinos are close in mass and one is different, but physicists don't know whether there are two light ones and one heavy one (the so-called normal hierarchy) or the other way around (the inverted hierarchy). Physicists with the $278 million NOνA experiment at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, hope to determine the ordering by firing muon neutrinos to a 14,000-tonne detector (above) in northern Minnesota and looking for electron neutrinos emerging in the beam. The first year's data yield between six and 11 conversions—somewhat more than expected—and hint that the hierarchy is normal, NOνA researchers reported at the lab today. The result suggests that NOνA will eventually deliver a definitive answer—which is not a sure bet. Other experiments to test whether the neutrino is, weirdly, its own antiparticle may be feasible only if the hierarchy is inverted.

The universe is in a long, slow decline to darkness (AAAS)

The universe is cooling down, its stars pumping out about half as much energy as they did 2 billion years ago. So says a group of astronomers that has studied more than 200,000 galaxies, measuring how much energy they produce across a wide range of wavelengths. Astronomers have known since the 1990s that the total energy output from stars has been on the slide. From the birth of the first stars some 150 million years after the big bang (which created all energy and matter in the universe), nuclear fusion in their cores has been converting matter into energy—the energy that makes stars shine. But stars don’t shine forever; eventually they run out of fuel and die. Astronomers don’t know when the universe’s energy output peaked, but, according to members of the Galaxy and Mass Assembly (GAMA) project, we’re well past that point now. The GAMA team has peered through some of the largest and most powerful telescopes on the planet to explore galaxy evolution in the nearby universe. Using the Anglo-Australian Telescope, Europe’s VLT Survey Telescope and the Visible and Infrared Survey Telescope for Astronomy, and the Australian Square Kilometre Array Pathfinder, as well as orbiting observatories such as NASA’s Galaxy Evolution Explorer and Wide-field Infrared Survey Explorer and Europe’s Herschel, they found energy output from a large portion of nearby space was dropping across all of 21 different wavelengths, from ultraviolet to far infrared (see above). Releasing their data today at the International Astronomical Union general assembly in Honolulu, the GAMA team says the universe is well advanced on a long, slow decline toward a cold, dark future

Our early solar system may have been home to a fifth giant planet

Primordial particles filled the outer solar system early in its lifetime. As the orbits of Jupiter (green circle), Saturn (orange circle), Neptune (dark blue circle), and Uranus (light blue circle) shifted over time, gravitational interactions tossed many of these icy rocks into the region today known as the Kuiper belt.

A cluster of icy bodies in the same region as Pluto could be proof that our early solar system was home to a fifth giant planet, according to new research. That planet may have “bumped” Neptune during its migration away from the sun 4 billion years ago, causing the ice giant to jump into its current orbit and scattering a cluster of its satellites into the Kuiper belt in the outer solar system.

The cluster—a grouping of about a thousand icy rocks called the “kernel”—has long been a mystery to astronomers. The rocks stick close together and never veer from the same orbital plane as the planets, unlike the other icy bodies that inhabit the belt. Previous studies proposed that the tightly bound objects formed from violent collisions of larger parent bodies, but that hypothesis fell apart as soon as scientists realized these collisional families would have to be stretched across the Kuiper belt.

But now, one scientist may have an answer for this Kuiper belt mystery. David Nesvorny, an astronomer at the Southwest Research Institute in Boulder, Colorado, proposes the jumping Neptune theory in the September issue of The Astronomical Journal. Using computer simulations to trace the movements of the kernel back about 4 billion years, he found the objects had been swept up in Neptune’s gravitational field as the planet migrated away from the sun. Leaving its orbit near Saturn and Jupiter, Neptune pulled bits of the primordial solar system along with it as they rotated in tandem: The infant kernel traveled around the sun twice for every trip that Neptune made.

At approximately 4.2 billion kilometers from the sun—close to its current position almost halfway to the outer edge of the modern-day Kuiper belt—Neptune’s orbit lurched outward 7.5 million kilometers. The trapped objects couldn't keep up with the sudden change of pace, and they were jolted out of their orbital configuration 6.9 billion kilometers from the sun, where they continue to travel today as the kernel.

Nesvorny says the only possible explanation for the sudden shift in orbit is that Neptune came under the gravitational sway of another object with a massive gravitational field—likely a giant planet. Uranus, Saturn, and Jupiter aren’t candidates because their orbits have never interacted with Neptune’s in the way that this proposed planet’s might have done.

No one knows what became of the missing planet, but when Nesvorny developed a previous model in 2011, he found that the best way to wind up with the present-day orbital configuration of the solar system was to include a fifth giant planet. The mystery giant was most likely ejected permanently from the solar system after disrupting the original orbits of the surviving planets, Nesvorny says—a casualty of its gravitational wrestling match. But back in 2011, he never thought he would find evidence of the planet’s possible existence.

“The Kuiper belt is the clue,” Nesvorny says. “You see the structures there, and you try to figure out what kind of evolution would fit those structures.”

But trying to figure it out isn’t so simple. Before landing on his current model of how the kernel could have formed, Nesvorny tested about 100 other possibilities. One of the most difficult parts of modeling, says astronomer JJ Kavelaars of the Dominion Astrophysical Observatory in Victoria, Canada, is to get multiple objects in the solar system to end up in the right place. Early models for the formation of Pluto, for example, put the dwarf planet in the correct location but neglected other parts of the solar system.

"What Nesvorny's models are doing is being very self-consistent and getting multiple structures right at once, which is really quite amazing," says Kavelaars, who was not involved in the research.

Nesvorny says the next step is to identify more objects in the Kuiper belt, particularly in the kernel. This could help scientists perform more precise comparisons that could improve the accuracy of the model. Nesvorny hopes observations from the Outer Solar System Origins Survey later this summer will fill in some of the gaps.

"I'm very much looking forward to seeing what kind of observations they will have and how it fits the modeling," Nesvorny says.

Mars; Crab-like & woman-like rock features

Circulating on social media, picture captued by Curiosity of crablike feature.

Similarly, the woman-like figure also circulating.

Primeval Procreation: Strawberrylike Animal Shows Oldest Reproduction (Nature)

A soft-bodied, fernlike creature reproduced in Earth's ancient oceans about 565 million years ago, making it the earliest known example of procreation in a complex organism, a new study finds.

Many scientists consider the creatures, called rangeomorphs, some of Earth's first complex animals, although it's impossible to know exactly what these organisms were, the researchers said. The creatures prospered in the ocean during the late Ediacaran period, between 580 million and 541 million years ago, just before the Cambrian era. Rangeomorphs could grow up to 6.5 feet (2 meters) in length, but most were about 4 inches (10 centimeters) long.

What's more, rangeomorphs don't appear to have been equipped with mouths, organs or the ability to move around, and the animals likely absorbed nutrients from the water, the researchers said. However, these ancient organisms had an unusually complex reproductive strategy for their time: They likely sent out an "advance party" to settle a new neighborhood, and then colonized the new area, the researchers said.
"Rangeomorphs don't look like anything else in the fossil record, which is why they're such a mystery," study lead author Emily Mitchell, a postdoctoral researcher in the University of Cambridge's department of earth sciences, said in a statement. "But we've developed a whole new way of looking at them, which has helped us understand them a lot better — most interestingly, how they reproduced."
Mitchell and her colleagues looked at fossils of a rangeomorph known as a Fractofusus found in Newfoundland, in southeastern Canada. Like other rangeomorphs, Fractofusus was immobile, and so its fossils capture exactly where the creatures lived in relation to one another during the Ediacaran period.

Using a combination of statistical techniques, high-resolution GPS and computer modeling, the researchers found an intriguing pattern in the distribution of Fractofusus populations. The larger Fractofusus, or "grandparent" specimens, were randomly distributed around the environment, surrounded by distinctive populations of smaller "parent" and "children" Fractofusus, the researchers said.

These patterns of grandparent, parent and children Fractofusus are similar to biological clustering seen in modern plants, the researchers said. In fact, it's likely the creatures had two reproductive methods: The grandparents were likely born from ejected waterborne seeds or spores, whereas the parents and children likely grew from "runners," sent by the older generation, just as strawberry plants grow today.

The "generational" clustering suggests that Fractofusus reproduced asexually using runners called stolons. However, it's unclear whether the waterborne seeds or spores were sexual or asexual in nature, the researchers said.

"Reproduction in this way made rangeomorphs highly successful, since they could both colonize new areas and rapidly spread once they got there," said Mitchell. "The capacity of these organisms to switch between two distinct modes of reproduction shows just how sophisticated their underlying biology was, which is remarkable at a point in time when most other forms of life were incredibly simple."

However, Fractofusus isn’t the only organism with complex reproductive strategies reproducing during that time. A 565-million-year-old tubular invertebrate named Funisia dorothea also lived in clusters, reports a 2008 study in the journal Science. It’s possible that Funisia sent eggs and sperm into the water, a technique called spatfall that is still used by modern coral and sponges. Funisia may have also grown by using an assexual technique called budding, in which a new individual break off from the parent organism, the 2008 study found.

Rangeomorphs disappeared from the fossil record at the beginning of the Cambrian period, about 540 million years ago, making it difficult to link them to modern organisms, the researchers said. But this type of spatial analysis may help reconstruct the reproductive strategies used by other Ediacaran organisms, and help scientists understand how the organisms interacted with each other as well as their environments, the researchers said.

Tracking A Mysterious Group of Asteroid Outcasts

High above the plane of our solar system, near the asteroid-rich abyss between Mars and Jupiter, scientists have found a unique family of space rocks. These interplanetary oddballs are the Euphrosyne (pronounced you-FROH-seh-nee) asteroids, and by any measure they have been distant, dark and mysterious -- until now.
Distributed at the outer edge of the asteroid belt, the Euphrosynes have an unusual orbital path that juts well above the ecliptic, the equator of the solar system. The asteroid after which they are named, Euphrosyne -- for an ancient Greek goddess of mirth -- is about 156 miles (260 kilometers) across and is one of the 10 largest asteroids in the main belt. Current-day Euphrosyne is thought to be a remnant of a massive collision about 700 million years ago that formed the family of smaller asteroids bearing its name. Scientists think this event was one of the last great collisions in the solar system.
A new study conducted by scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, used the agency's orbiting Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) telescope to look at these unusual asteroids to learn more about Near Earth Objects, or NEOs, and their potential threat to Earth.
NEOs are bodies whose orbits around the sun approach the orbit of Earth; this population is short-lived on astronomical timescales and is fed by other reservoirs of bodies in our solar system. As they orbit the sun, NEOs can occasionally have close approaches to Earth. For this reason alone -- the safety of our home planet -- the study of such objects is important.
As a result of their study, the JPL researchers believe the Euphrosynes may be the source of some of the dark NEOs found to be on long, highly inclined orbits. They found that, through gravitational interactions with Saturn, Euphrosyne asteroids can evolve into NEOs over timescales of millions of years.
NEOs can originate in either the asteroid belt or the more distant outer reaches of the solar system. Those from the asteroid belt are thought to evolve toward Earth's orbit through collisions and the gravitational influence of the planets. Originating well above the ecliptic and near the far edge of the asteroid belt, the forces that shape their trajectories toward Earth are far more moderate.
"The Euphrosynes have a gentle resonance with the orbit of Saturn that slowly moves these objects, eventually turning some of them into NEOs," said Joseph Masiero, JPL's lead scientist on the Euphrosynes study. "This particular gravitational resonance tends to push some of the larger fragments of the Euphrosyne family into near-Earth space."
By studying the Euphrosyne family asteroids with NEOWISE, JPL scientists have been able to measure their sizes and the amount of solar energy they reflect. Since NEOWISE operates in the infrared portion of the spectrum, it detects heat. Therefore, it can see dark objects far better than telescopes operating at visible wavelengths, which sense reflected sunlight. Its heat-sensing capability also allows it to measure sizes more accurately.
The 1,400 Euphrosyne asteroids studied by Masiero and his colleagues turned out to be large and dark, with highly inclined and elliptical orbits. These traits make them good candidates for the source of some of the dark NEOs the NEOWISE telescope detects and discovers, particularly those that also have highly inclined orbits.
NEOWISE was originally launched as an astrophysics mission in 2009 as the Wide-field Infrared Survey Explorer, or WISE. It operated until 2011 and was then shut down. But the spacecraft, now dubbed NEOWISE, would get a second life. "NEOWISE is a great tool for searching for near-Earth asteroids, particularly high-inclination, dark objects," Masiero said.
There are over 700,000 asteroidal bodies currently known in the main belt that range in size from large boulders to about 60 percent of the diameter of Earth's moon, with many yet to be discovered. This makes finding the specific point of origin of most NEOs extremely difficult.
With the Euphrosynes it's different. "Most near-Earth objects come from a number of sources in the inner region of the main belt, and they are quickly mixed around," Masiero said. "But with objects coming from this family, in such a unique region, we are able to draw a likely path for some of the unusual, dark NEOs we find back to the collision in which they were born."
A better understanding of the origins and behaviors of these mysterious objects will give researchers a clearer picture of asteroids in general, and in particular the NEOs that skirt our home planet's neighborhood. Such studies are important, and potentially critical, to the future of humanity, which is a primary reason JPL and its partners continue to relentlessly track these wanderers within our solar system. To date, U.S. assets have discovered more than 98 percent of the known NEOs.

Powerful Auroras Found at Brown Dwarf

Mysterious objects called brown dwarfs are sometimes called "failed stars." They are too small to fuse hydrogen in their cores, the way most stars do, but also too large to be classified as planets. But a new study in the journal Nature suggests they succeed in creating powerful auroral displays, similar to the kind seen around the magnetic poles on Earth.
"This is a whole new manifestation of magnetic activity for that kind of object," said Leon Harding, a technologist at NASA's Jet Propulsion Laboratory, Pasadena, California, and co-author on the study.
On Earth, auroras are created when charged particles from the solar wind enter our planet's magnetosphere, a region where Earth's magnetic field accelerates and sends them toward the poles. There, they collide with atoms of gas in the atmosphere, resulting in a brilliant display of colors in the sky.
"As the electrons spiral down toward the atmosphere, they produce radio emissions, and then when they hit the atmosphere, they excite hydrogen in a process that occurs at Earth and other planets," said Gregg Hallinan, assistant professor of astronomy at the California Institute of Technology in Pasadena, who led the team. "We now know that this kind of auroral behavior is extending all the way from planets up to brown dwarfs."
Brown dwarfs are generally cool, dim objects, but their auroras are about a million times more powerful than auroras on Earth, and if we could somehow see them, they'd be about a million times brighter, Hallinan said. Additionally, while green is the dominant color of earthly auroras, a vivid red color would stand out in a brown dwarf's aurora because of the higher hydrogen content of the object's atmosphere.
The foundation for this discovery began in the early 2000s, when astronomers began finding radio emissions from brown dwarfs. This was surprising because brown dwarfs do not generate large flares and charged-particle emissions the way the sun and other kinds of stars do. The cause of these radio emissions was a big question.
Hallinan discovered in 2006 that brown dwarfs can pulse at radio frequencies, too. This pulsing phenomenon is similar to what is seen from planets in our solar system that have auroras.
Harding, working as part of Hallinan's group while pursuing his doctoral studies, found that there was also periodic variability in the optical wavelength of light coming from brown dwarfs that pulse at radio frequencies. He published these findings in the Astrophysical Journal. Harding built an instrument called an optical high-speed photometer, which looks for changes in the light intensity of celestial objects, to examine this phenomenon.
The combination of results made scientists wonder: Could this variability in light from brown dwarfs be caused by auroras?
In this new study, researchers examined brown dwarf LSRJ1835+3259, located about 20 light-years from Earth. Scientists studied it using some of the world's most powerful telescopes -- the National Radio Astronomy Observatory's Very Large Array, Socorro, New Mexico, and the W.M. Keck Observatory's telescopes in Hawaii -- in addition to the Hale Telescope at the Palomar Observatory in California.
Given that there's no stellar wind to create an aurora on a brown dwarf, researchers are unsure what is generating it on LSRJ1835+3259. An orbiting planet moving through the magnetosphere of the brown dwarf could be generating a current, but scientists will have to map the aurora to figure out its source.
The discovery reported in the July 30 issue of Nature could help scientists better understand how brown dwarfs generate magnetic fields. Additionally, brown dwarfs will help scientists study exoplanets, planets outside our solar system, as the atmosphere of cool brown dwarfs is similar to what astronomers expect to find at many exoplanets.
"It's challenging to study the atmosphere of an exoplanet because there's often a much brighter star nearby, whose light muddles observations. But we can look at the atmosphere of a brown dwarf without this difficulty," Hallinan said.

Earth Flyby of 'Space Peanut' Captured in New Video

NASA scientists have used two giant, Earth-based radio telescopes to bounce radar signals off a passing asteroid and produce images of the peanut-shaped body as it approached close to Earth this past weekend.
The asteroid appears to be a contact binary -- an asteroid with two lobes that are stuck together.
The images show the rotation of the asteroid, named 1999 JD6, which made its closest approach on July 24 at 9:55 p.m. PDT (12:55 a.m. EDT on July 25) at a distance of about 4.5 million miles (7.2 million kilometers, or about 19 times the distance from Earth to the moon).

"Radar imaging has shown that about 15 percent of near-Earth asteroids larger than 600 feet [about 180 meters], including 1999 JD6, have this sort of lobed, peanut shape," said Lance Benner of NASA's Jet Propulsion Laboratory in Pasadena, California, who leads NASA's asteroid radar research program.
To obtain the views, researchers paired NASA's 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, California, with the 330-foot (100-meter) National Science Foundation Green Bank Telescope in West Virginia. Using this approach, the Goldstone antenna beams a radar signal at an asteroid and Green Bank receives the reflections. The technique, referred to as a bistatic observation, dramatically improves the amount of detail that can be seen in radar images. The new views obtained with the technique show features as small as about 25 feet (7.5 meters) wide.
The individual images used in the movie were generated from data collected on July 25. They show the asteroid is highly elongated, with a length of approximately 1.2 miles (2 kilometers) on its long axis. The movie spans a period of about seven hours, 40 minutes.
This week's flyby was the closest approach the asteroid will make to Earth for about the next 40 years. The next time it will approach Earth this closely is in 2054, at approximately the same distance of this week's flyby.
Data from the new observations will be particularly useful to Sean Marshall, a graduate student at Cornell University in Ithaca, New York, whose doctoral research on 1999 JD6 is funded by NASA's Near-Earth Object Program. "I'm interested in this particular asteroid because estimates of its size from previous observations, at infrared wavelengths, have not agreed. The radar data will allow us to conclusively resolve the mystery of its size to better understand this interesting little world," he said.
Despite the uncertainty about its size, asteroid 1999 JD6 has been studied extensively and many of its physical properties, as well as its trajectory, are well known. It rotates in just over seven-and-a-half hours and is thought to be a relatively dark object. Asteroid 1999 JD6 was discovered on May 12, 1999, by the Lowell Observatory Near-Earth-Object Search, located in Flagstaff, Arizona.
Radar is a powerful technique for studying an asteroid's size, shape, rotation, surface features and surface roughness, and for improving the calculation of asteroid orbits. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than would be possible otherwise.
NASA places a high priority on tracking asteroids and protecting our home planet from them. In fact, the U.S. has the most robust and productive survey and detection program for discovering near-Earth objects (NEOs). To date, U.S. assets have discovered over 98 percent of the known NEOs.
In addition to the resources NASA puts into understanding asteroids, it also partners with other U.S. government agencies, university-based astronomers, and space science institutes across the country, often with grants, interagency transfers and other contracts from NASA, and also with international space agencies and institutions that are working to track and better understand these objects.

'Magnetic' Discovery May Reveal Why Earth Supports Life and Mars Doesn't (Journal of Science)

Earth's magnetic field, which protects the planet from harmful blasts of solar radiation, is much older than scientists had previously thought, researchers say. In fact, this invisible, protective shield likely existed shortly after the planet formed — a finding that could shed light on why Earth is habitable and Mars is not.

Without Earth's magnetic field, solar winds — streams of electrically charged particles that flow from the sun — would strip away the planet's atmosphere and oceans. As such, Earth's magnetic field helped to make life on the planet possible, researchers have said.

The magnetic field is generated by swirling liquid metal in Earth's outer core, and this "geodynamo" requires the release of heat from the planet to drive its churning. Nowadays, this heat flow is aided by plate tectonics — the movement of the plates of rock that make up the planet's exterior — which efficiently lets heat transfer from Earth's interior to its surface.
Given the importance of Earth's magnetic field, scientists want to pinpoint when it first developed, which could, in turn, provide clues about how the planet has been able to remain habitable and when plate tectonics began. However, when, exactly, plate tectonics originated is hotly debated, and some researchers argue that the early Earth lacked a magnetic field.

Since 2010, the best estimate of the age of Earth's magnetic field was 3.45 billion years. In comparison, Earth is about 4.6 billion years old.

Now, scientists have found that Earth's magnetic field could be up to 4.2 billion years old — about 750 million years older than had been previously thought.

The researchers investigated magnetically sensitive minerals such as magnetite, a naturally occurring cousin of rust. As molten rock cools, magnetite within it becomes literally set in stone, pointing to the location of Earth's magnetic poles at the moment it froze. As a result, the oldest samples of magnetite can reveal the direction and intensity of Earth's magnetic field at the earliest parts of Earth's history, the researchers said.

The scientists analyzed magnetite samples trapped in tiny, ancient zircon crystals that were collected from the Jack Hills in Western Australia. To detect the magnetic fields, the scientists had to have a special magnetic sensor built that was 10 times more sensitive than other instruments used to make these kinds of measurements.
Isolating the zircons from the surrounding rock was challenging. "Typically, we separate zircons out using high magnetic fields, but we couldn't do that here, since it would destroy what information they had," said John Tarduno, a geophysicist at the University of Rochester in New York and lead author of the new study detailing the findings. "So we had to separate thousands of zircons out by hand, cleaning them in mild acids, which took a huge amount of time," Tarduno told Live Science.

Then, to get reliable measurements, the researchers had to make sure the samples they analyzed never got hot enough after they formed to allow the magnetic information recorded within to reset. The researchers found that the minerals were pointed in a variety of magnetic directions, which suggested the samples were pristine.

"[I]f the magnetic information in the zircons had been erased and re-recorded, the magnetic directions would have all been identical," Tarduno said in a statement.

The intensity of the magnetic fields that the samples recorded suggests the presence of an ancient geodynamo, the researchers said.

These findings likely indicate that Earth had a magnetic field, and plate tectonics, since very early in its history.

"It's surprising, because some of the models of the ancient Earth suggest that a magnetic field or plate tectonics could not have occurred that early," Tarduno said. "Those models need to be rethought to include potential ways of cooling Earth's interior early on."

This ancient magnetic field could be a key reason Earth is still habitable and Mars was unable to sustain life, as far as we currently know.

"The oldest previously known magnetic field from a terrestrial planet was on Mars, which was older than 4 billion years old," Tarduno said. "But then, sometime after 4 billion years ago, it died off. If you compare the evolution of Earth and Mars, Mars had a more dense atmosphere, and water, but it probably lost both to erosion from the solar wind because it didn't have a magnetic field to protect them, whereas Earth always appeared to have had a strong magnetic shield."

Two telescopes have teamed up to measure of a distant alien world about the size of Uranus (Journal of Astrophysics)

Two telescopes have teamed up to  measure of a distant alien world about the size of Uranus that had remained almost a complete mystery since its discovery a decade ago.

The exoplanet, known as OGLE-2005-BLG-169Lb, lies about 8,800 light-years from Earth. It was first discovered in 2005 via "gravitational microlensing," a technique that involves watching what happens when a big foreground object (often a star) passes in front of a background star from our perspective on Earth. The nearby body's gravitational field bends and magnifies the light from the distant star, acting like a lens.

Such lensing events can reveal a great deal about the foreground object — for example, in the case of a star, whether or not it hosts any exoplanets, and how massive those worlds are compared to their host star.
Getting a read on OGLE-2005-BLG-169Lb has been tough, however, because many characteristics of its host star were unknown. The 2005 lensing event occurred in a crowded star field, which made it difficult to separate the background star from its neighbors, NASA officials said.

But researchers have now succeeded in separating the star out, thanks to observations made by NASA's Hubble Space Telescope in orbit and the ground-based Keck Observatory in Hawaii.

"These chance alignments are rare, occurring only about once every 1 million years for a given planet, so it was thought that a very long wait would be required before the planetary microlensing signal could be confirmed," David Bennett, leader of the team that analyzed Hubble's observations, said in a statement.

"Fortunately, the planetary signal predicts how fast the apparent positions of the background star and planetary host star will separate, and our observations have confirmed this prediction," Bennett added. "The Hubble and Keck Observatory data, therefore, provide the first confirmation of a planetary microlensing signal."

Even though Hubble and Keck studied the system 6.5 and 8 years, respectively, after the 2005 lensing event, their data allowed astronomers to determine that OGLE-2005-BLG-169Lb is about 14 times more massive than Earth and orbits 370 million miles (595 million kilometers) from its host star.

To put that into perspective: The alien planet is about as massive as Uranus and lies 75 percent as far from its star as Jupiter is from the sun (though OGLE-2005-BLG-169Lb's parent star is just 70 percent as massive as the sun).
Astronomers have confirmed more than 800 planets beyond our own solar system, and the discoveries keep rolling in.
"It is the first time we were able to completely resolve the source star and the lensing star after a microlensing event," Virginie Batista, leader of the team that analyzed Keck's data, said in the same statement. "This enabled us to discriminate between two models that fit the data of the microlensing light curve."

OGLE-2005-BLG-169Lb appears to be a "failed Jupiter" planet, researchers said. That is, it accumulated a large core of rock and ice but didn't grow fast enough to snag a lot of hydrogen and helium, as Jupiter was able to do.

“Failed Jupiter planets, like OGLE-2005-BLG-169Lb, are predicted to be more common than Jupiters, especially around stars less massive than the sun, according to the preferred theory of planet formation," Bennett said. "So this type of planet is thought to be quite common."

The Hubble and Keck observations could also aid in the development of NASA's proposed Wide-Field Infrared Survey Telescope (WFIRST), a powerful space mission the agency hopes to launch in the 2020s.

"WFIRST will make measurements like we have made for OGLE-2005-BLG-169 for virtually all the planetary microlensing events it observes," Bennett said. "We’ll know the masses and distances for the thousands of planets discovered by WFIRST."

Gravitational microlensing is not the only technique scientists use to discover alien planets. In fact, two other strategies — the transit method and the radial velocity method — have yielded the vast majority of exoplanet finds.

The transit method (used by NASA's Kepler space telescope, among other instruments) involves searching for the tiny brightness dips caused when an orbiting planet crosses its star's face. The radial velocity technique looks for minuscule wobbles in a star's movement caused by the gravitational tugs of orbiting planets.

Both the transit and radial velocity methods are best at detecting relatively large worlds that lie close to their parent stars. But gravitational microlensing provides a good way to spot distantly orbiting exoplanets, potentially extending the reach of surveys and censuses, researchers said.

The Hubble and Keck observations are reported in two studies in the July 30 edition of The Astrophysical Journal.

Cassini Grand Finale: Saturn Mission's Daring End

Like all good things, epic space missions must come to an end. But in the case of NASA’s Cassini mission around Saturn, it’s going to end in dramatic style.
After a decade in orbit around the ringed gas giant Cassini has revolutionized our understanding of Saturn’s rings, moons and dynamic atmosphere. It’s even put Earth in its place, as a tiny blue dot in the vast expanse of space.
Sadly, Cassini can’t soldier on forever; it will run out of fuel (used by its thrusters for adjustments during orbit) — but that’s not necessarily a bad thing.
Until now, mission managers have tried to protect the spacecraft from any orbital risks in the interest of prolonging Cassini’s life, but as the mission is now coming to a close, they can afford to be a little less careful while looking for awesome science opportunities. Starting in 2016, Cassini will be commanded to carry out a “daring set of orbits that is, in some ways, like a whole new mission,” writes NASA in a recent news release.
Known as “proximal orbits,” the spacecraft will fly high above Saturn’s poles and then fly outside the planet’s narrow F-ring. This orbital path will take it past the icy moon Enceladus, allowing another passage through the moon’s fascinating water-rich plumes that blast into space.
Then, its trajectory will evolve to make a dive between the innermost ring and the planet 22 times. Flying through the ring plane will increase the potential for impacts with ring dust, ice grains and even large rocks, so until now such an orbital profile has been avoided at all costs.
What happens next? Well, assuming it doesn’t hit anything in the meantime, to avoid an end-of-mission collision with Titan or Enceladus — two Saturnian moons with biological potential that scientists do not want to contaminate with any hardy Earth-borne bacteria that may be hitching a ride on the probe — Cassini will plunge into Saturn’s atmosphere, burning up in a fiery final act.
Now that the mission is entering a very final and distinct phase of its decade-long Saturn odyssey, NASA has asked for mission-naming ideas. After the Cassini’s primary mission, it was renamed “Cassini Equinox” (2008) then “Cassini Solstice” (2010) after each mission extension, which related to the changing seasons on Saturn. Now, after considering suggestions from 2,000 members of the public, this final act will be known as the “Cassini Grand Finale.”
“We chose a name for this mission phase that would reflect the exciting journey ahead while acknowledging that it’s a big finish for what has been a truly great show,” said Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
So we still have a couple of breathtaking years as Cassini slowly approaches its most intimate encounter with Saturn yet — returning unique photographs and historic science as it zooms through Saturn’s rings

NASA's Spitzer Confirms Closest Rocky Exoplanet & Where to Find It.

Using NASA's Spitzer Space Telescope, astronomers have confirmed the discovery of the nearest rocky planet outside our solar system, larger than Earth and a potential gold mine of science data.
Dubbed HD 219134b, this exoplanet, which orbits too close to its star to sustain life, is a mere 21 light-years away. While the planet itself can't be seen directly, even by telescopes, the star it orbits is visible to the naked eye in dark skies in the Cassiopeia constellation, near the North Star.

HD 219134b is also the closest exoplanet to Earth to be detected transiting, or crossing in front of, its star and, therefore, perfect for extensive research.
"Transiting exoplanets are worth their weight in gold because they can be extensively characterized," said Michael Werner, the project scientist for the Spitzer mission at NASA's Jet Propulsion Laboratory in Pasadena, California. "This exoplanet will be one of the most studied for decades to come."
The planet, initially discovered using the HARPS-North instrument on the Italian 3.6-meter Galileo National Telescope in the Canary Islands, is the subject of a study accepted for publication in the journal Astronomy & Astrophysics.
Study lead author Ati Motalebi of the Geneva Observatory in Switzerland said she believes the planet is the ideal target for NASA's James Webb Space Telescope in 2018.
"Webb and future large, ground-based observatories are sure to point at it and examine it in detail," Motalebi said.
Only a small fraction of exoplanets can be detected transiting their stars due to their relative orientation to Earth. When the orientation is just right, the planet's orbit places it between its star and Earth, dimming the detectable light of its star. It's this dimming of the star that is actually captured by observatories such as Spitzer and can reveal not only the size of the planet but also clues about its composition.
"Most of the known planets are hundreds of light-years away. This one is practically a next-door neighbor," said astronomer and study co-author Lars A. Buchhave of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. For reference, the closest known planet is GJ674b at 14.8 light-years away; its composition is unknown.
HD 219134b was first sighted by the HARPS-North instrument and a method called the radial velocity technique, in which a planet's mass and orbit can be measured by the tug it exerts on its host star. The planet was determined to have a mass 4.5 times that of Earth, and a speedy three-day orbit around its star.
Spitzer followed up on the finding, discovering the planet transits its star. Infrared measurements from Spitzer revealed the planet's size, about 1.6 times that of Earth. Combining the size and mass gives it a density of 3.5 ounces per cubic inch (six grams per cubic centimeter) -- confirming HD 219134b is a rocky planet.
Now that astronomers know HD 219134b transits its star, scientists will be scrambling to observe it from the ground and space. The goal is to tease chemical information out of the dimming starlight as the planet passes before it. If the planet has an atmosphere, chemicals in it can imprint patterns in the observed starlight.
Rocky planets such as this one, with bigger-than-Earth proportions, belong to a growing class of planets termed super-Earths.
"Thanks to NASA's Kepler mission, we know super-Earths are ubiquitous in our galaxy, but we still know very little about them," said co-author Michael Gillon of the University of Liege in Belgium, lead scientist for the Spitzer detection of the transit. "Now we have a local specimen to study in greater detail. It can be considered a kind of Rosetta Stone for the study of super-Earths."
Further observations with HARPS-North also revealed three more planets in the same star system, farther than HD 219134b. Two are relatively small and not too far from the star. Small, tightly packed multi-planet systems are completely different from our own solar system, but, like super-Earths, are being found in increasing numbers.

Hubble Video

A Steve Knight video animation inspired by Hubble, with the music of Miriam Stockley.   Just sit back and enjoy!!!!!   https://www.youtube.com/watch?v=C7EalNrUrEU

Philae poses comet chemistry conundrum (Chemistry World 30th July)

As the Philae lander bounced across comet 67P/Churyumov–Gerasimenko’s surface in November last year, two chemical instruments were able to take tentative – but intriguingly contradictory – sniffs of its environment. Those mass spectrometry measurements provide compositional details important for deciphering the origins of life on Earth, a key aim of the Rosetta mission that carried Philae. But while the cometary sampling and composition (COSAC) instrument detected 16 organic molecules¹, half of which contain nitrogen atoms, Ptolemy reports very low concentrations of nitrogen-containing compounds².

Nevertheless, Jen Blank, a senior scientist at the Nasa Ames Research Center in California, US, highlights the historic achievement of syncing orbit with a comet and sending a lander down to the surface. ‘The Philae data are amazing,’ enthuses Blank, who’s studied how comets may have supplied Earth with molecules needed for life, but wasn’t involved in Rosetta or Philae. ‘These are the first measurements of organic compounds collected directly on a comet or asteroid.’
Philae was programmed to take sniffs shortly after touching down on 67P as an ‘insurance policy’, explains Ian Wright from the Open University in Milton Keynes, UK, and principal investigator for Ptolemy. That was well planned, because the touchdown became a rebound that sent Philae out of communication range, preventing further measurements to date.
The lander was also therefore in motion in the minutes between the instruments doing their respective basic analyses, or sniffs, of whatever material happened to have entered them. One potential explanation for the distinct results is therefore that they reflect differences between locations on the comet, Wright suggests. The fact that COSAC’s sample port is on Philae’s underside, and Ptolemy’s is on its top is another. ‘Have we analysed separate grains?’ Wright asks. ‘We’ve no reason to expect that the surface would be homogenous.’

Exhausting serendipity

COSAC’s best sniff happened automatically 25 minutes after Philae’s first contact, while the lander was around 150 metres above the surface. The instrument consists of a gas chromatograph and a time-of-flight mass spectrometer intended to analyse organic compounds in samples drilled from the comet’s surface. Though Philae couldn’t drill, the impact threw up some solid material, part of which apparently entered COSAC’s two exhaust pipes. The COSAC team, headed by Fred Goesmann from the Max Planck Institute for Solar System Research in Göttingen, Germany, thinks the exhaust’s warmth evaporated volatile compounds, allowing their detection.

The compounds COSAC identified included methyl isocyanate, acetone, propionaldehyde and acetamide, which have not previously been reported in comets. Acetamide is also one of four compounds detected that can produce important biological molecules like amino acids, sugars and DNA bases. Blank is especially excited by acetamide’s presence. ‘It's easy to imagine a pathway to an amino acid,’ she says. However, Goesmann is cautious not to read too much into their presence. ‘Comets with such a composition do not work against life,’ he tells Chemistry World. ‘In the right environment, emerging life could make use of it.’

However, the small amount of material COSAC was looking at meant it couldn’t detect anything but the smallest compounds. That means it wouldn’t have seen any ‘molecules of life’, such as amino acids, even if they were present. And although it could have, it didn’t see much ammonia, formaldehyde or carbon dioxide, which are common components of cometary ice, or any sulfur compounds. The COSAC scientists link the lack of ice to measurements previously made by Rosetta showing 67P’s surface is covered in a carbon-based coat rather than frozen.

Icy isolation

To determine isotope ratios of chemicals on 67P and establish their origins, Ptolemy’s gas chromatograph and ion trap mass spectrometer were also supposed to be fed drilled samples. However, it was reduced to making six sniffs at 14 second intervals about 20 minutes after Philae hit 67P. Like COSAC, it failed to find any signs of sulfur. Ptolemy saw mostly water and carbon dioxide, ice components expected on comets, but no significant indication of ammonia, and very low levels of nitrogen compounds overall. The COSAC scientists suggest that the absence of this key source of nitrogen could be because it has evaporated or been used up in reactions.

Ptolemy also found hints of polyoxymethylene, a polymer thought to be produced from formaldehyde by cosmic radiation, previously detected on Halley’s Comet. This source of formaldehyde is another important potential resource for origin-of-life chemistry, Wright underlines. ‘It can produce simple sugars like ribose,’ he says. ‘These are things that we hope will be picked up by astrobiologists in refining their ideas.’

John Plane from the atmospheric and planetary chemistry group at the University of Leeds calls these measurements ‘technically incredible’. ‘It’s a wonderful achievement to get any data,’ he says. Plane is especially pleased because COSAC’s findings support lab experiments showing cometary ice can produce small organic molecules. ‘It’s nice to have them confirmed, and get a first idea of relative abundance,’ he says. ‘That’s useful if you want to simulate the next step, how these molecules could react together to make peptides and DNA.’
Meanwhile, Rosetta has recently regained tenuous contact with Philae, enough for scientific commands to be sent to Ptolemy last week, Wright reveals. ‘We haven’t got any data back,’ he admits. ‘When we get a communication window it might come back, but it’s a fingers crossed job. As time goes on we’re becoming less convinced that’s going to happen.’

Could Our Universe Have Features of A Giamt Black Hole? (Journal of Cosmology, June 2015)

Interesting article from Journal of Cosmology; using black hole data along with Schwarzschild's equation and average density equat, the size and mass of our visible universe plots on a logarithimic scale.

Abstract;

 The 2013 Planck Survey results yielded the following estimates for mass (1.46 x 1053kg), radius (4.3 x 1026 m) and average density (4.08 x 10-28 kg/m3) for the visible portion of our universe. These mass and density numbers are for the baryonic (“ordinary”) matter portion only. These data can be plotted in close proximity (within approximately a factor of 2) to the projection lines of a logarithmic graph of calculated black hole mass vs. Schwarzschild radius and black hole average density vs. Schwarzschild radius, respectively. The Schwarzschild formula, rs = 2GM/c2, and a simple black hole average density formula, Ro = 3c2/8piGrs 2, are used to calculate mass and average density for theoretical black holes ranging from microscopic to the radius of our visible universe, and these values are plotted on the logarithmic graph.
The possible implications of these findings are discussed, including a rationale for the possibility that the largest black holes (giant “dark black holes”) may be beyond our capability to detect them. It remains to be seen whether adding in dark matter massand average density contributions to the graph would put our universe exactly on the black hole projection lines, or within the shaded territory exclusive to black holes, but the possibility of this happening is not ruled out at the present time.

http://journalofcosmology.com/JOC25/COULD%20OUR%20UNIVERSE%20HAVE%20FEATURES%20OF%20A%20GIANT%20BLACK%20HOLE%20in%20Word%20copy%202-1

A galactic vampire - The Milky Way is not as young as it looks (The Economist, 21st Feb)

AS EVERY horror fan knows, the secret of eternal youth is to suck the lifeblood of others. If you are a galaxy, that lifeblood is hydrogen gas, from which stars form. And it seems that some galaxies are indeed able to maintain a youthful appearance by sucking great clouds of the stuff in from intergalactic space.
According to Felix Lockman of America’s National Radio Astronomy Observatory, the Milky Way, humanity’s home galaxy, is one such vampire. Dr Lockman is part of a team that has been using the Green Bank radio telescope in West Virginia, which boasts the world’s largest steerable dish, to study the process.

The mystery to be solved is why, of the visible matter in the Milky Way, around 15% is still in the form of gas and dust. The galaxy is over 13 billion years of age, almost as old as the universe itself. In theory, that is plenty of time for all of its gas to have condensed into stars, as has happened in a class of galaxies known as ellipticals. But the Milky Way is a spiral galaxy, in which active star-formation continues at the rate of about one newborn a year. This must mean that the galactic supply of hydrogen is somehow being replenished. And Dr Lockman and his colleagues think they know how.

In the 1960s a strange intergalactic gas cloud was discovered near the Milky Way by an astronomer called Gail Smith. Smith’s cloud, as it is known, is an elongated structure almost 10,000 light-years from end to end. At roughly a tenth of the diameter of the Milky Way’s disc, that is big even by galactic standards. Smith’s cloud was a puzzle. No other such object had ever been seen. It was therefore put aside by astronomers, for it is hard to do useful science when you have only one example of something. Dr Lockman and his colleagues have now rectified that neglect. Their measurements show the cloud is on a collision course with the Milky Way. It will hit one of the arms of the spiral in about 30m years, and then be absorbed into the galaxy, probably triggering a burst of star formation in the process.
This suggested to the team that they had found the mechanism of eternal galactic youth: galaxies eat gas clouds. If that were true it would imply that such clouds must be quite common.
And that is what theory predicts. Recent calculations about how matter is distributed in the universe suggest that a good number of such clouds should, indeed, be out there. These calculations concern not the hydrogen itself, but the real fabric of the universe: a still-mysterious substance known as dark matter that interacts with the familiar, atomic, sort only through the force of gravity. The calculations suggest that there should be dark-matter globs of the right mass to attract interstellar gas clouds as big as Smith’s. And when Dr Lockman used Green Bank to search for such clouds, he found ten in just one small volume of nearby space.
The mystery of the ever-youthful Milky Way thus seems to be solved. Spiral galaxies are constantly rejuvenated by collisions with things like Smith’s cloud. Eventually, the supply of these clouds will run out, and with it the elixir of galactic life. But that will not be for many billions of years. Meanwhile, the universe’s spiral galaxies will keep on keeping young.

Researchers call for interstellar messages to alien civilizations (sciencemag.org)

SAN JOSE, CALIFORNIA—Is it time to send deliberate messages to the stars, in the hopes of reaching alien civilizations? Advocates in the Search for Extraterrestrial Intelligence (SETI) say that moment is long overdue. But other researchers want to take a more cautious approach and seek an international consensus before outing Earth to the rest of the universe. Scientists in both camps faced off today at a debate held at a meeting of AAAS (which publishes Science) here.

Douglas Vakoch, the director of interstellar message composition at the SETI Institute in Mountain View, California, doesn’t dismiss the need to consider ethical or political issues, but says that it will be tough to achieve a consensus. “It’s ‘either-or’ thinking,” he says. “Either we have international discussion, or we transmit. We should be doing both.” But David Brin, an astrophysicist and science fiction author here, says that Earth’s relative radio quietude should not be changed so radically, so quickly. “If you’re going to transform one of the major characteristics … of our planet, we’ve learned that small groups shouldn’t do that peremptorily.
Since the SETI movement began in the 1960s, it has mostly involved using radio telescopes to listen to bands in the electromagnetic spectrum for something out of the ordinary. In contrast, instances of active SETI, also called Messaging Extraterrestrial Intelligence, or METI—beaming deliberate messages to the heavens—have been much rarer. In 1974, a radio message was broadcast from the Arecibo telescope in Puerto Rico toward a cluster of stars 25,000 light-years away. Brin says there have been other “stunts.” In 2008, for instance, the tortilla chip company Doritos sent an advertisement from a radar station in Norway to a potentially habitable star system 42 light-years away.

Advocates for active SETI say that keen-eared aliens could already pick up some of Earth’s ambient transmissions. Current radio and TV transmissions could be heard only a few light-years away with the current radio telescope technology on Earth, but Vakoch says that an advanced civilization would have far more developed techniques for listening. Brin says this is the “barn door excuse” and adds that many active SETI techniques would send out focused, powerful messages that would travel many times farther than the day-to-day transmissions from Earth. He views active SETI messages as cosmic pollution, rather than exploration. Although he’s not worried about alien invasions, he thinks the assumption of benevolence—or even the existence of aliens—is overstated.

Vakoch says the SETI Institute has no imminent plans to start transmitting messages, but he finds that other organizations are not taking the lead in holding international discussions on the issue. He says that one efficient way of transmitting messages would be by adding messages in the regular course of doing planetary science. When the Arecibo radar is used to study asteroids, for instance, messages could be sent to stars near the line of sight of the asteroid without much additional effort. What would these messages include? Seth Shostak, an astronomer at the SETI Institute, wants to beam the entire Internet. Vakoch would prefer something humble that conveys the challenges that humanity faces.

Brin doesn’t see resolution to the passionate debate anytime soon. “It’s an area where opinion rules, and everyone has a fierce opinion.”

SETI Debates the Wisdom of Revealing Ourselves to the Galaxy (AAAS Feb 2015)

Should we shout.....or should we keep quiet...?

SAN JOSE, California — They don't hold out much hope that Vulcans will arrive on our doorsteps intoning "live long and prosper," but many astronomers believe that making radio contact with an alien civilization would fundamentally alter humanity for the better.  For fifty years, however, they have searched the sky for signs of intelligent beings elsewhere in the universe with no result. Some think it's time to start sending our own messages to the stars in hope that someone up there will reply.
So-called "active SETI" is controversial. Astrophysicist Steven Hawking famously cautioned against shouting out our presence into the void, saying that first contact "… didn't turn out very well for the Native Americans." In response to such concerns, the nonprofit SETI Institute held one of the first public debates on the wisdom of active SETI, at the AAAS annual meeting.
The chances of someone picking up the message are better than ever. Recent data "encourages those who are optimistic about life in the universe," said astrobiologist David Grinspoon of the Planetary Science Institute at a 12 February news conference. Scientists now believe one in five sun-like stars have planets with conditions suitable for life, he reported. And research on extreme organisms on Earth, which eke out existence in the most challenging of environments, suggests that life could survive in even more unlikely places. The more common life in general is, Grinspoon suggested, the more probable that some of it has evolved intelligence and perhaps the ability to communicate.
SETI astronomer Douglas Vakoch argued that the time has come to stop waiting for some other galactic civilization to establish contact with us and make the first gesture ourselves. After all, if no one is transmitting messages, we don't have much chance of hearing one. "Sometimes we talk about SETI as an attempt to join the galactic club," Vakoch said, "but no one ever talks about paying our dues or even submitting an application."
The first step, Vakoch said, is to send out a signal that an extraterrestrial version of the SETI project could pick up. The message, he suggested, could be sent in the spare time of the Arecibo telescope in Puerto Rico, which astronomer Frank Drake used to send a coded message to a distant star cluster in 1974.
Speaking out against blabbing our presence to the stars was David Brin of Futures Unlimited in San Diego. Perhaps we haven't heard from alien civilizations because we're listening in the wrong place or with the wrong technology, he said. Perhaps they are waiting for us to make the first move. Or, maybe there's a more sinister explanation. Given the lack of any solid data, he said, SETI scientists' assumption that any galactic civilization capable of communicating with us would be benign is a dangerous one.
Brin called for a self-imposed halt on active broadcasts until there can be a global discussion of the potential risks and benefits. He compared this to the pause biologists placed on genetic engineering in the early 1990s to discuss the technology's risks and best practices. This moratorium, Brin said, ultimately resulted in better and safer research. In particular, he called for the inclusion of historians who could caution astronomers about the potential dangers of making contact. Here on Earth, Brin said, no first contact between peoples has ever been painless, even when there have been the best of intentions.

"'I Love Lucy' is washing over the shores of a new planet out there on average once a day."

Seth Shostack

The possible benefits of making contact far outweigh the risks, said Seth Shostak, a senior astronomer at SETI. He argued that any alien civilization that could reach us to do us harm would be more than capable of detecting us already. Any extra terrestrial with technology just a few centuries beyond ours, he estimated, could find us based on the radio and television broadcasts we have inadvertently beamed into space since the mid-20th Century. "Our leakage is 70 light years into space," he said. "'I Love Lucy' is washing over the shores of a new planet out there on average once a day."

Brin called Shostak's claims assertions based on assumptions rather than data. "We are learning so much so fast," Brin said. "Fifteen years ago we knew of no planets outside our solar system — now it's thousands." Wouldn't make more sense, he asked, to pause and learn more before doing something that could change the fate of the world forever? Perhaps the risks of shouting into the interstellar jungle are small, but they are real, he said. "What we are saying is 'Let's talk about it.'"

Today's debate is just one step in an ongoing exploration of actively pinging the galaxy. The SETI Institute plans to hold a day-long workshop Saturday at its Mountain View campus. The meeting is slated to include the perspectives of historians and religious scholars, according to SETI Institute CEO David Black, who organized the meeting. The objective, Black said, is to start figuring out how to regulate and plan any active SETI efforts. Currently, he said, there's no law preventing people from renting time on a radio telescope and "firing off a signal." The potential impact of announcing ourselves to the galaxy is immense, he said, and he expects a long debate. If we decide to pick up the phone, the next question is what we want to say.

Lunar & Planetary Institute Flickr Site

Includes some of the New Horizon shots of Pluto.......

https://www.flickr.com/photos/lunarandplanetaryinstitute/

Unusual Red Arcs Spotted on Icy Saturn Moon

Like graffiti sprayed by an unknown artist, unexplained arc-shaped, reddish streaks are visible on the surface of Saturn's icy moon Tethys in new, enhanced-color images from NASA's Cassini spacecraft.
The red arcs are narrow, curved lines on the moon's surface, and are among the most unusual color features on Saturn's moons to be revealed by Cassini's cameras.
Images taken using clear, green, infrared and ultraviolet spectral filters were combined to create the enhanced-color views, which highlight subtle color differences across the icy moon's surface at wavelengths not visible to human eyes.
A few of the red arcs can be seen faintly in observations made earlier in the Cassini mission, which has been in orbit at Saturn since 2004. But the color images for this observation, obtained in April 2015, are the first to show large northern areas of Tethys under the illumination and viewing conditions necessary to see the arcs clearly. As the Saturn system moved into its northern hemisphere summer over the past few years, northern latitudes have become increasingly well illuminated. As a result, the arcs have become clearly visible for the first time.
"The red arcs really popped out when we saw the new images," said Cassini participating scientist Paul Schenk of the Lunar and Planetary Institute in Houston. "It's surprising how extensive these features are."
The origin of the features and their reddish color is a mystery to Cassini scientists. Possibilities being studied include ideas that the reddish material is exposed ice with chemical impurities, or the result of outgassing from inside Tethys. They could also be associated with features like fractures that are below the resolution of the available images.
Except for a few small craters on Saturn's moon Dione, reddish-tinted features are rare on other moons of Saturn. Many reddish features do occur, however, on the geologically young surface of Jupiter's moon Europa.
"The red arcs must be geologically young because they cut across older features like impact craters, but we don't know their age in years." said Paul Helfenstein, a Cassini imaging scientist at Cornell University, Ithaca, New York, who helped plan the observations. "If the stain is only a thin, colored veneer on the icy soil, exposure to the space environment at Tethys' surface might erase them on relatively short time scales."
The Cassini team is currently planning follow-up observations of the features, at higher resolution, later this year.
"After 11 years in orbit, Cassini continues to make surprising discoveries," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "We are planning an even closer look at one of the Tethys red arcs in November to see if we can tease out the source and composition of these unusual markings."

New Names and Insights at Ceres

 Colorful new maps of Ceres, based on data from NASA's Dawn spacecraft, showcase a diverse topography, with height differences between crater bottoms and mountain peaks as great as 9 miles (15 kilometers).
Scientists continue to analyze the latest data from Dawn as the spacecraft makes its way to its third mapping orbit.
"The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres. The features are pretty consistent with an ice-rich crust," said Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston.
Some of these craters and other features now have official names, inspired by spirits and deities relating to agriculture from a variety of cultures. The International Astronomical Union recently approved a batch of names for features on Ceres.
The newly labeled features include Occator, the mysterious crater containing Ceres' brightest spots, which has a diameter of about 60 miles (90 kilometers) and a depth of about 2 miles (4 kilometers). Occator is the name of the Roman agriculture deity of harrowing, a method of leveling soil.
Colorful new maps of Ceres, based on data from NASA's Dawn spacecraft, showcase a diverse topography, with height differences between crater bottoms and mountain peaks as great as 9 miles (15 kilometers).
Scientists continue to analyze the latest data from Dawn as the spacecraft makes its way to its third mapping orbit.
"The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres. The features are pretty consistent with an ice-rich crust," said Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston.
Some of these craters and other features now have official names, inspired by spirits and deities relating to agriculture from a variety of cultures. The International Astronomical Union recently approved a batch of names for features on Ceres.
The newly labeled features include Occator, the mysterious crater containing Ceres' brightest spots, which has a diameter of about 60 miles (90 kilometers) and a depth of about 2 miles (4 kilometers). Occator is the name of the Roman agriculture deity of harrowing, a method of leveling soil.
A smaller crater with bright material, previously labeled "Spot 1," is now identified as Haulani, after the Hawaiian plant goddess. Haulani has a diameter of about 20 miles (30 kilometers). Temperature data from Dawn's visible and infrared mapping spectrometer show that this crater seems to be colder than most of the territory around it.
Dantu crater, named after the Ghanaian god associated with the planting of corn, is about 75 miles (120 kilometers) across and 3 miles (5 kilometers) deep. A crater called Ezinu, after the Sumerian goddess of grain, is about the same size. Both are less than half the size of Kerwan, named after the Hopi spirit of sprouting maize, and Yalode, a crater named after the African Dahomey goddess worshipped by women at harvest rites.
"The impact craters Dantu and Ezinu are extremely deep, while the much larger impact basins Kerwan and Yalode exhibit much shallower depth, indicating increasing ice mobility with crater size and age," said Ralf Jaumann, a Dawn science team member at the German Aerospace Center (DLR) in Berlin.
Almost directly south of Occator is Urvara, a crater named for the Indian and Iranian deity of plants and fields. Urvara, about 100 miles (160 kilometers) wide and 3 miles (6 kilometers) deep, has a prominent central pointy peak that is 2 miles (3 kilometers) high.
Dawn is currently spiraling toward its third science orbit, 900 miles (less than 1,500 kilometers) above the surface, or three times closer to Ceres than its previous orbit. The spacecraft will reach this orbit in mid-August and begin taking images and other data again.
Ceres, with a diameter of 584 miles (940 kilometers), is the largest object in the main asteroid belt, located between Mars and Jupiter. This makes Ceres about 40 percent the size of Pluto, another dwarf planet, which NASA's New Horizons mission flew by earlier this month.
On March 6, 2015, Dawn made history as the first mission to reach a dwarf planet, and the first to orbit two distinct extraterrestrial targets. It conducted extensive observations of Vesta in 2011-2012.