Here's How Scientists Teleported the First Object Into Space

Scientists from China have just performed the first ever quantum teleportation from Earth to space. Does this mean we are now living in the future envisioned in Star Trek?

Actually, no physical matter was actually “beamed up,” unfortunately — just photons. But this breakthrough might make for a better and more secure internet in the future.

"Quantum teleportation brings to mind Star Trek’s transporter, where crew members are disassembled in one location to be reassembled in another,” explained astrophysicist Brian Koberlein from the Rochester Institute of Technology. “Real quantum teleportation is a much more subtle effect where information is transferred between entangled quantum states. It’s a quantum trick that could give us the ultimate in secure communication."

Long-distance quantum communication has been recognized as a keystone for things like large-scale quantum networks and quantum computation. But previous quantum communications — or “teleportation” — experiments have seen limited success.

Entanglement is a tenuous state, with the link easily broken. Previous attempts using fiber networks have been limited to distances of 100 km or less due to photon loss inside the fiber. Some of the first attempts at “over-the-air” teleportation using light beams were only successful at night because of daytime atmospheric turbulence.

“An outstanding open challenge for a global-scale ‘quantum internet’ is to significantly extend the range for teleportation,” wrote Ji-Gang Ren and his colleagues in their new paper about the teleportation feat. They said that the most promising solution to the distance problem is to exploit satellites, which can “conveniently connect two remote points on the Earth with greatly reduced channel loss because most of the photons’ propagation path is in empty space.”

The weird phenomenon of entanglement might seem difficult to fathom, but it occurs when two quantum objects, such as photons, form at the same instant and point in space. Basically, they share the same existence and the state of one object affects the state of the other. But in theory, this shared existence should continue even when the photons are separated by long distances.

“For quantum teleportation, one of these entangled objects is measured in combination with the object to be ‘teleported,’” explained Koberlein, who was not involved with the research, “and the result of this measurement is then sent to another location, where a similar combined measurement is made. Since the entangled objects are part of both measurements, quantum information can be teleported.”

For the latest attempt by the Chinese researchers, they used a new satellite called Micius that was launched last year by a Long March rocket. The satellite contains an extremely sensitive photon receiver that can detect the quantum states of single photons transmitted from the ground.

They used several techniques to “optimize the link efficiency and overcome atmospheric turbulence,” including a “compact ultra-bright source of multi-photon entanglement, narrow beam divergence, high-bandwidth and high-accuracy acquiring, pointing, and tracking.”

They were successful with quantum teleportation from Earth to space at distances of up to 1,400 km, the furthest ever. The link-up wasn’t 100 percent successful however, as out of millions of photon states they attempted to transmit into space, just over 900 of them were successful.

Read more at Discovery News

Eye microbiome trains immune cells to fend off pathogens in mice

C. mast is a commensal bacterium living on the surface of the eye.

Bugs in your eyes may be a good thing. Resident microbes living on the eye are essential for immune responses that protect the eye from infection, new research shows. The study, which appears in the journal Immunity on July 11, demonstrates the existence of a resident ocular microbiome that trains the developing immune system to fend off pathogens. The research was conducted at the National Eye Institute (NEI), part of the National Institutes of Health.

"This is the first evidence that a bacterium lives on the ocular surface long-term," explained Rachel Caspi, Ph.D., senior investigator in NEI's Laboratory of Immunology. "This work addresses a longstanding question about whether there is a resident ocular microbiome."

For years, the ocular surface was thought to be sterile because of the presence of an enzyme called lysozyme that destroys bacteria, antimicrobial peptides, and other factors that rid the eye of microbes that may land from the air (or from our fingers) onto the surface of the eye.

Anthony St. Leger, Ph.D., research fellow in Caspi's laboratory, was able to culture bacteria from the mouse conjunctiva, the membrane that lines the eyelids. He found several species of Staphylococci, which are commonly found on the skin, and Corynebacterium mastitidis (C. mast). But it wasn't clear whether those microbes had just arrived on the eye and were en route to being destroyed, or whether they lived on the eye for extended periods of time.

The researchers found that C. mast, when cultured with immune cells from the conjunctiva, induced the production of interleukin (IL)-17, a signaling protein critical for host defense. Upon further investigation, they found that IL-17 was produced by gamma delta T cells, a type of immune cell found in mucosal tissues. IL-17 attracted other immune cells called neutrophils -- the most abundant type of white blood cell -- to the conjunctiva and induced the release of anti-microbial proteins into the tears. The researchers are currently investigating the unique features that can make C. mast resistant to the immune response that it itself provokes and allow it to persist in the eye.

To determine whether the microbe was contributing to the immune response in mice, St. Leger formed two groups, one control (with C. mast) and one treated with an antibiotic to kill C. mast and other ocular bacteria, and then challenged them with the fungus, Candida albicans. The mice receiving antibiotics had a reduced immune response in their conjunctiva and were not able to eliminate C. albicans, leading to full-blown ocular infection. The control mice with normal C. mast on the other hand were able to fend off the fungus.

St. Leger noticed that mice from the NIH animal facility had C. mast on their eyes, but mice from the Jackson Laboratory (JAX) in Maine and other commercial vendors did not. This fortuitous observation allowed the researchers to determine if C. mast was truly a resident microbe, as opposed to a transient microbe that lands on the eye from the environment. They did this by inoculating C. mast-free mice with the microbe and determining if the microbe could be cultured from those animals' eyes many weeks later. They also determined whether the microbe could easily be transmitted among cagemates.

When inoculated with C. mast, JAX mice produced conjunctival gamma delta T cells that released IL-17. Bacteria could still be cultured from their eyes after many weeks. By contrast, several other strains of bacteria inoculated onto the eyes of JAX mice disappeared without inducing local immunity. "We still don't know what enables C. mast to successfully establish itself in the eye, whereas other similar bacteria fail to colonize," Caspi said.

Interestingly, C. mast was not spread to cage-mates even after eight weeks of co-housing; however, C. mast can be passed from mother to pup. Both of these observations support the notion that C. mast is a resident commensal, not a bacterium that is continually re-introduced to the eye from the skin or the environment, Caspi explained.

Although C. mast appears to stimulate a beneficial immune response, there may be situations in which it could cause disease, St. Leger noted. For instance, the elderly tend to have suppressed immune systems, which might allow C. mast to grow out of control and cause disease.

The researchers are currently investigating whether other bacteria play a role in regulating eye immunity.

"We've established the proof of concept of a central ocular microbiome," St. Leger said. "It's well known that there are good bacteria in the gut that modulate the immune response. Now we show that this relationship exists in the eye. That's important for how we think about treating ocular disease."

Read more at Science Daily

The one trillion ton iceberg: Larsen C Ice Shelf rift finally breaks through

This is a map showing detachment of iceberg, based on data from NASA's Aqua Modis satellite. July 12, 2017.

A one trillion tonne iceberg -- one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice, monitored by the Swansea University-led MIDAS project, finally completed its path through the ice.

The calving occurred sometime between Monday 10th July and Wednesday 12th July, when a 5,800 square km section of Larsen C finally broke away.

The final breakthrough was detected in data from NASA's Aqua MODIS satellite instrument, which images in the thermal infrared at a resolution of 1km.

• The iceberg, which is likely to be named A68, weighs more than a trillion tonnes.
• Its volume is twice that of Lake Erie, one of the Great Lakes.

The iceberg weighs more than a trillion tonnes (1,000,000,000,000 metric tonnes), but it was already floating before it calved away so has no immediate impact on sea level. The calving of this iceberg leaves the Larsen C Ice Shelf reduced in area by more than 12%, and the landscape of the Antarctic Peninsula changed forever.

The development of the rift over the last year was monitored using data from the European Space Agency Sentinel-1 satellites -- part of the European Copernicus Space Component. Sentinel-1 is a radar imaging system capable of acquiring images regardless of cloud cover, and throughout the current winter period of polar darkness. The detachment of the iceberg was first revealed in a thermal infrared image from NASA's MODIS instrument, which is also able to acquire data in the Antarctic winter when cloud cover permits.

Although the remaining ice shelf will continue naturally to regrow, Swansea researchers have previously shown that the new configuration is potentially less stable than it was prior to the rift. There is a risk that Larsen C may eventually follow the example of its neighbour, Larsen B, which disintegrated in 2002 following a similar rift-induced calving event in 1995.

Professor Adrian Luckman of Swansea University, lead investigator of the MIDAS project, said:

"We have been anticipating this event for months, and have been surprised how long it took for the rift to break through the final few kilometres of ice. We will continue to monitor both the impact of this calving event on the Larsen C Ice Shelf, and the fate of this huge iceberg.

The iceberg is one of the largest recorded and its future progress is difficult to predict. It may remain in one piece but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters.

The recent development in satellite systems such as Sentinel-1 and MODIS has vastly improved our ability to monitor events such as this."

The Larsen C Ice Shelf, which has a thickness of between 200 and 600 metres, floats on the ocean at the edge of The Antarctic Peninsula, holding back the flow of glaciers that feed into it.

Researchers from the MIDAS Project have been monitoring the rift in Larsen C for many years, following the collapse of the Larsen A ice shelf in 1995 and the sudden break-up of the Larsen B shelf in 2002. They reported rapid advances of the rift in January, May and June, which increased its length to over 200 km and left the iceberg hanging on by a thread of ice just 4.5 km (2.8 miles) wide.

The team monitored the earlier development of the rift using a technique called satellite radar interferometry (SRI) applied to ESA Sentinel-1 images. While the rift is only visible in radar images when it is more than 50m wide, by combining pairs of images, SRI allows the impact of very small changes in ice shelf geometry to be detected, and the rift tip to be monitored precisely.

Dr Martin O'Leary, a Swansea University glaciologist and member of the MIDAS project team, said of the recent calving:

"Although this is a natural event, and we're not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history. We're going to be watching very carefully for signs that the rest of the shelf is becoming unstable."

Professor Adrian Luckman of Swansea University added:

"In the ensuing months and years, the ice shelf could either gradually regrow, or may suffer further calving events which may eventually lead to collapse -- opinions in the scientific community are divided. Our models say it will be less stable, but any future collapse remains years or decades away."

Read more at Science Daily

Planet Nine hypothesis supported by new evidence

Will another planet be added to the list of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune in our Solar System?

Last year, the existence of an unknown planet in our Solar system was announced. However, this hypothesis was subsequently called into question as biases in the observational data were detected. Now Spanish astronomers have used a novel technique to analyse the orbits of the so-called extreme trans-Neptunian objects and, once again, they point out that there is something perturbing them: a planet located at a distance between 300 to 400 times the Earth-Sun separation.

Scientists continue to argue about the existence of a ninth planet within our Solar System. At the beginning of 2016, researchers from the California Institute of Technology (Caltech, USA) announced that they had evidence of the existence of this object, located at an average distance of 700 AU or astronomical units (700 times the Earth-Sun separation) and with a mass ten times that of Earth.

Their calculations were motivated by the peculiar distribution of the orbits found for the trans-Neptunian objects (TNO) of the Kuiper belt, which apparently revealed the presence of a Planet Nine or X in the confines of the Solar System.

However, scientists from the Canadian-French-Hawaiian project OSSOS detected biases in their own observations of the orbits of the TNOs, which had been systematically directed towards the same regions of the sky, and considered that other groups, including the Caltech group, may be experiencing the same issues. According to these scientists, it is not necessary to propose the existence of a massive perturber (a Planet Nine) to explain these observations, as these are compatible with a random distribution of orbits.

Now, however, two astronomers from the Complutense University of Madrid have applied a new technique, less exposed to observational bias, to study a special type of trans-Neptunian objects: the extreme ones (ETNOs, located at average distances greater than 150 AU and that never cross Neptune's orbit). For the first time, the distances from their nodes to the Sun have been analysed, and the results, published in the journal 'MNRAS: Letters', once again indicate that there is a planet beyond Pluto.

The nodes are the two points at which the orbit of an ETNO, or any other celestial body, crosses the plane of the Solar System. These are the precise points where the probability of interacting with other objects is the largest, and therefore, at these points, the ETNOs may experience a drastic change in their orbits or even a collision.

Like the comets that interact with Jupiter

"If there is nothing to perturb them, the nodes of these extreme trans-Neptunian objects should be uniformly distributed, as there is nothing for them to avoid, but if there are one or more perturbers, two situations may arise," explains Carlos de la Fuente Marcos, one of the authors. "One possibility is that the ETNOs are stable, and in this case they would tend to have their nodes away from the path of possible perturbers, he adds, but if they are unstable they would behave as the comets that interact with Jupiter do, that is tending to have one of the nodes close to the orbit of the hypothetical perturber."

Using calculations and data mining, the Spanish astronomers have found that the nodes of the 28 ETNOs analysed (and the 24 extreme Centaurs with average distances from the Sun of more than 150 AU) are clustered in certain ranges of distances from the Sun; furthermore, they have found a correlation, where none should exist, between the positions of the nodes and the inclination, one of the parameters which defines the orientation of the orbits of these icy objects in space.

"Assuming that the ETNOs are dynamically similar to the comets that interact with Jupiter, we interpret these results as signs of the presence of a planet that is actively interacting with them in a range of distances from 300 to 400 AU," says De la Fuente Marcos, who emphasizes: "We believe that what we are seeing here cannot be attributed to the presence of observational bias."

Until now, studies that challenged the existence of Planet Nine using the data available for these trans-Neptunian objects argued that there had been systematic errors linked to the orientations of the orbits (defined by three angles), due to the way in which the observations had been made. Nevertheless, the nodal distances mainly depend on the size and shape of the orbit, parameters which are relatively free of observational bias.

"It is the first time that the nodes have been used to try to understand the dynamics of the ETNOs," the co-author points out, as he admits that discovering more ETNOs (at the moment, only 28 are known) would permit the proposed scenario to be confirmed and subsequently constrain the orbit of the unknown planet via the analysis of the distribution of the nodes.

The authors note that their study supports the existence of a planetary object within the range of parameters considered both in the Planet Nine hypothesis of Mike Brown and Konstantin Batygin from Caltech, and in the original one proposed in 2014 by Scott Sheppard from the Carnegie Institute and Chadwick Trujillo from the University of North Arizona; in addition to following the lines of their own earlier studies (the latest led by the Instituto de Astrofísica de Canarias), which suggested that there is more than one unknown planet in our Solar System.

Is there also a Planet Ten?

De la Fuente Marcos explains that the hypothetical Planet Nine suggested in this study has nothing to do with another possible planet or planetoid situated much closer to us, and hinted at by other recent findings. Also applying data mining to the orbits of the TNOs of the Kuiper Belt, astronomers Kathryn Volk and Renu Malhotra from the University of Arizona (USA) have found that the plane on which these objects orbit the Sun is slightly warped, a fact that could be explained if there is a perturber of the size of Mars at 60 AU from the Sun.

Read more at Science Daily

Stunning Close-Ups of Jupiter's Great Red Spot From Juno Probe Flyby Are Here

The giant storm on Jupiter known as the Great Red Spot has been raging for centuries. Now scientists may finally be on the verge of attaining greater insight into this tempest.

Images and data are being returned to Earth from the Juno spacecraft’s recent close pass over the GRS on Monday, July 10, when it passed directly above the coiling crimson cloud tops at a height of just 5,600 miles (9,000 kilometers). The spacecraft's eight instruments gathered data, including its citizen science-based imager, JunoCam. As soon as the raw images hit the JunoCam website, amateur image processing gurus pounced into action.

The images — the closest ever taken of the GRS — weren’t expected to be available until July 14 because the spacecraft’s main antenna was pointed away from Earth during the closest approach. But they arrived earlier that expected on Wednesday.

“The Juno team must have fast-tracked them!” enthused amateur image processor Kevin Gill, who works as a science data software engineer at NASA's Jet Propulsion Laboratory.

The science team knows there has been avid public interest in Juno’s seventh science flyby over Jupiter’s cloud tops that focused on the GRS.

"This monumental storm has raged on the solar system's biggest planet for centuries,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “Now, Juno and her cloud-penetrating science instruments will dive in to see how deep the roots of this storm go, and help us understand how this giant storm works and what makes it so special."

It will likely take weeks or perhaps months for the science team to analyze the data gathered by Juno’s instruments in order to reveal some of the enduring storm’s secrets. But JunoCam images processed by amateurs can be seen here.

“We made JunoCam an instrument that belongs to the public,” Juno’s Project Scientist Steve Levin told me last year. “We solicit the aid of the public in picking which areas to look at and making the maps that go in to the images and processing the data, and releasing the data to the world. We release it in the rawest form we can, and allow the public to make the images.”

The JunoCam images captured three different views of the GRS. One that looks at the northern edge, one centered as Juno fly right over the GRS, and one looking from the south. The third one also included data with a methane filter.

While the images are stunning, it will be the other instruments that will reveal the most insights into the GRS, the storm that is twice as big as Earth.

While astronomers have actively monitored the GRS since the early 1800s, and other spacecraft such as Voyager in the late 1970s and Galileo in the 1990s, "there’s still a lot of mystery surrounding this massive storm," said Bolton.

Questions abound, such as why is the storm red? Why has it​ endured for so long, and why has​ it been shrinking over the past several years?

Read more at Seeker

Cassini Spacecraft Captures Breathtaking Image of Sunrise on Saturn

This is what dawn on Saturn looks like, from afar.

The ringed planet is partly hidden in darkness and partly illuminated by the faint light of a distant sun in a gorgeous photo taken by NASA's Cassini spacecraft.

"The light has traveled around 80 minutes since it left the sun's surface by the time it reaches Saturn," NASA officials wrote in a description of the image, which was released yesterday (July 10). "The illumination it provides is feeble; Earth gets 100 times the intensity, since it's roughly 10 times closer to the sun. Yet compared to the deep blackness of space, everything at Saturn still shines bright in the sunlight, be it direct or reflected."[Cassini's Saturn 'Grand Finale' Plan in Pictures]

Cassini took the photo on Feb. 25, at a distance of about 762,000 miles (1.23 million kilometers) from the ringed planet.

The $3.2 billion Cassini-Huygens mission — a joint effort of NASA, the European Space Agency, and the Italian Space Agency — has been orbiting Saturn since July 2004, but its days are numbered: The spacecraft is scheduled to plunge into the gas giant's cloud tops on Sept. 15, in an intentional death dive designed to ensure that Cassini doesn't contaminate the Saturn moons Titan or Enceladus with microbes from Earth. (Both Titan and Enceladus may be capable of supporting life, scientists have said.)

Huygens was a piggyback lander that separated from the Cassini mothership and made a historic touchdown on Titan in January 2005 — the first soft touchdown ever achieved on a body in the outer solar system.

From Seeker

Tracking the birth of a 'super-earth'

This is an artist’s impression of a young star surrounded by a protoplanetary disk in which planets (not shown to scale) are forming.

A new model giving rise to young planetary systems offers a fresh solution to a puzzle that has vexed astronomers ever since new detection technologies and planet-hunting missions such as NASA's Kepler space telescope have revealed thousands of planets orbiting other stars: While the majority of these exoplanets fall into a category called super-Earths -- bodies with a mass somewhere between Earth and Neptune -- most of the features observed in nascent planetary systems were thought to require much more massive planets, rivaling or dwarfing Jupiter, the gas giant in our solar system.

In other words, the observed features of many planetary systems in their early stages of formation did not seem to match the type of exoplanets that make up the bulk of the planetary population in our galaxy.

"We propose a scenario that was previously deemed impossible: how a super-Earth can carve out multiple gaps in disks," says Ruobing Dong, the Bart J. Bok postdoctoral fellow at the University of Arizona's Steward Observatory and lead author on the study, soon to be published in the Astrophysical Journal. "For the first time, we can reconcile the mysterious disk features we observe and the population of planets most commonly found in our galaxy."

How exactly planets form is still an open question with a number of outstanding problems, according to Dong.

"Kepler has found thousands of planets, but those are all very old, orbiting around stars a few billion years old, like our sun," he explains. "You could say we are looking at the senior citizens of our galaxy, but we don't know how they were born."

To find answers, astronomers turn to the places where new planets are currently forming: protoplanetary disks -- in a sense, baby sisters of our solar system.

Such disks form when a vast cloud of interstellar gas and dust condenses under the effect of gravity before collapsing into a swirling disk. At the center of the protoplanetary disk shines a young star, only a few million years old. As microscopic dust particles coalesce to sand grains, and sand grains stick together to form pebbles, and pebbles pile up to become asteroids and ultimately planets, a planetary system much like our solar system is born.

"These disks are very short-lived," Dong explains. "Over time the material dissipates, but we don't know exactly how that happens. What we do know is that we see disks around stars that are 1 million years old, but we don't see them around stars that are 10 million years old."

In the most likely scenario, much of the disk's material gets accreted onto the star, some is blown away by stellar radiation and the rest goes into forming planets.

Although protoplanetary disks have been observed in relative proximity to the Earth, it is still extremely difficult to make out any planets that may be forming within. Rather, researchers have relied on features such as gaps and rings to infer the presence of planets.

"Among the explanations for these rings and gaps, those involving planets certainly are the most exciting and drawing the most attention," says co-author Shengtai Li, a research scientist at Los Alamos National Laboratory in Los Alamos, New Mexico. "As the planet orbits around the star, the argument goes, it may clear a path along its orbit, resulting in the gap we see."

Except that reality is a bit more complicated, as evidenced by two of the most prominent observations of protoplanetary disks, which were made with ALMA, the Atacama Large Millimeter/submillimeter Array in Chile. ALMA is an assembly of radio antennas between 7 and 12 meters in diameter and numbering 66 of them once completed. The images of HL Tau and TW Hydra, obtained in 2014 and 2016, respectively, have revealed the finest details so far in any protoplanetary disk, and they show some features that are difficult, if not impossible, to explain with current models of planetary formation, Dong says.

"Among the gaps in HL Tau and TW Hya revealed by ALMA, two pairs of them are extremely narrow and very close to each other," he explains. "In conventional theory, it is difficult for a planet to open such gaps in a disk. They can never be this narrow and this close to each other for reasons of the physics involved."

In the case of HL Tau and TW Hya, one would have to invoke two planets whose orbits hug each other very closely -- a scenario that would not be stable over time and therefore is unlikely.

While previous models could explain large, single gaps believed to be indicative of planets clearing debris and dust in their path, they failed to account for the more intricate features revealed by the ALMA observations.

The model created by Dong and his co-authors results in what the team calls synthetic observations -- simulations that look exactly like what ALMA would see on the sky. Dong's team accomplished this by tweaking the parameters going into the simulation of the evolving protoplanetary disk, such as assuming a low viscosity and adding the dust to the mix. Most previous simulations were based on higher disk viscosity and accounted only for the disk's gaseous component.

"The viscosity in protoplanetary disks may be driven by turbulence and other physical effects," Li says. "It's a somewhat mysterious quantity -- we know it's there, but we don't know its origin or how large its value is, so we think our assumptions are reasonable, considering that they result in the pattern that has actually been observed on the sky."

Even more important, the synthetic observations emerged from the simulations without the necessity to invoke gas giants the size of Jupiter or larger.

"One super-Earth turned out to be sufficient to create the multiple rings and multiple, narrow gaps we see in the actual observations," Dong says.

Read more at Science Daily

Uranus May Have a Magnetic Field that Flickers On and Off Like a Strobe Light

The planet Uranus just keeps getting weirder.

The icy gas world that strangely orbits the sun on its side may also have a wonky magnetic field that constantly flickers on and off, new research suggests.

Magnetic fields around planets, or magnetospheres, create shields against the bombardment of radiation from the sun known as solar wind. On Earth, for example, the magnetosphere lines up pretty closely with the planet's axis of rotation, and magnetic field lines emerge from Earth's north and south poles. On Uranus, however, the magnetosphere is a bit more chaotic.

Uranus' spin axis is tilted by a whopping 98 degrees, and the planet's off-center magnetic field is tilted by another 60 degrees. Every time the planet rotates (about every 17.24 hours), this lopsided magnetic field tumbles around, opening and closing periodically as the magnetic field lines disconnect and reconnect, the study found.

Researchers at the Georgia Institute of Technology (Georgia Tech) in Atlanta figured this out by simulating Uranus' messy magnetosphere using numerical models and data from NASA's Voyager 2 spacecraft, which flew by the planet in 1986.

"Uranus is a geometric nightmare," Carol Paty, an associate professor at Georgia Tech's School of Earth & Atmospheric Sciences and co-author of the study, said in a statement. "The magnetic field tumbles very fast, like a child cartwheeling down a hill head over heels. When the magnetized solar wind meets this tumbling field in the right way, it can reconnect, and [so] Uranus' magnetosphere goes from open to closed to open on a daily basis."

When the magnetosphere opens up, it allows solar particles to bombard the planet. Then, when the magnetic field lines reconnect, this natural shield can continue to block the solar wind.

This process may be related to auroras on Uranus. Just like the auroras on Earth and other planets, Uranus' atmosphere lights up when particles from the solar wind enter it and interact with gases like nitrogen and oxygen.

NASA's Hubble Space Telescope has previously observed auroras on Uranus, but astronomers face difficulties in studying how these auroras interact with the magnetosphere, because the planet is so far away — nearly 2 billion miles (3.2 billion kilometers) from Earth. The space agency is currently considering sending another spacecraft to Uranus and Neptune to investigate those planet's magnetic fields, among other things.

Xin Cao, a Ph.D. candidate at Georgia Tech who led the study, said that studying Uranus can teach scientists a lot about planets outside of the solar system. "The majority of exoplanets [worlds outside the solar system] that have been discovered appear to also be ice giants in size," he said. "Perhaps what we see on Uranus and Neptune is the norm for planets: very unique magnetospheres and less-aligned magnetic fields.

Read more at Seeker

Earth Faces ‘Biological Annihilation’ as Animal Populations Decline Dramatically

Deforestation along the Jari River, a northern tributary of the Amazon river, Brazil, May 2014

On June 24, 2012, Lonesome George, the last of the Pinta Island tortoises, died quietly in his pen at a research facility in the Galapagos.

The island where his species once flourished had been ravaged by a flock of goats introduced to the island by fishermen in 1959 as a source of fresh meat for their voyages. The goats devastated the island’s vegetation, wiping out the Pinta tortoises’ habitat.

You may not have heard of Lonesome George. But his death was a sign of our times.

Two vertebrate species go extinct every year amid a man-made mass extinction unrivaled since the dinosaurs died out 66 million years ago. Today, the phenomenon is known as the Sixth Extinction. Some 200 species have disappeared over the past century — a pace approximately 100 times faster than the “normal” rate.

At the turn of the millennium, Nobel prize winning atmospheric chemist Paul Crutzen and his colleague Eugene Stoermer published an article suggesting that humans had altered Earth so much that the planet should be thought to have entered a new geological epoch, which they dubbed the Anthropocene, or “Age of Humans.” The 11,700-year-old Holocene, which began at end of the most recent ice age and extended through the rise of modern human civilization, should be considered over, they argued.

Now, new research from scientists at the Universidad Nacional Autónoma de México and Stanford University provides a fresh picture of the size and scale of the threat facing the planet’s biodiversity at the hands of humanity.

“Earth’s sixth mass extinction is more severe than perceived,” constituting a “biological annihilation” that translates into a “frightening assault on the foundations of human civilization,” the study says.

The rate of loss of different types of species — two per year — doesn’t take into account the fact that surviving species are declining dramatically both in terms of their population numbers and in the geographical range over which they can be found, the authors write.

The scientists used geographical range as a proxy for population sizes, and looked at 27,600 vertebrate species, with an even more detailed analysis of 177 mammals between the years 1900 and 2015.

All of the 177 mammals lost 30 percent or more of their geographic ranges, according to the study, which was published in the Proceedings of the National Academy of Sciences. More than 40 percent of the species experienced severe range decline of over 80 percent.

The declining number of animals on earth “is already damaging the services ecosystems provide to civilization,” the authors wrote.

To be sure, not all dire warnings about the future of the planet pan out. One of the three authors of this very paper, Paul Erhlich, professor of population studies of the Department of Biology of Stanford University, famously predicted in his controversial 1968 book, "The Population Bomb," that overpopulation would lead to mass starvation and social upheaval in the 1970s and 1980s.

Read more at Seeker

Finding Extraterrestrial Life May Rely on Identifying Traces Rather Than Aliens

The surface of Mars.

When the famous 15th-century inventor and scientist Leonardo da Vinci examined petrified shells with borings in them long ago, he had a remarkable insight. The strange fossilized formations, he determined, were likely left behind by ancient organisms.

Half a millennium later, this perspective is potentially useful in our search for alien life, argues a new paper that appears in Earth-Science Reviews, whose findings were recently presented at the European Astrobiology Network Association congress in the Netherlands.

Astronomers have been weighing options for how to identify the existence of life on other planets and moons in our solar system. There are a range of possibilities. Mars could be host to ancient or current life, depending on how much water flows on the surface and how salty it is. There are also many icy moons (some with water geysers) in the outer regions of our solar system — among them Saturn’s Titan and Enceladus, and Jupiter’s Europa and Ganymede.

“Leonardo understood the biological nature of borings based on their shape, not their biochemistry,” said Andrea Baucon, the lead researcher. Baucon is an ichnologist, a type of scientist that studies life’s traces through burrows, borings and trails. He previously studied da Vinci’s work and is a researcher at the University of Modena and UNESCO Geopark Naturtejo.

“This observation appears to be trivial,” he went on, “but it potentially allows [us] to detect extra-terrestrial life that differs from known life.”

A major limitation of this kind of study, however, is that animal traces and alterations by geology can sometimes appear very similar. For example, researchers have identified what they say are more than four-billion-year-old fossils in formations in northern Quebec, Canada. This finding was announced earlier this year; in 2016, a separate team claimed to find 3.7-billion-year-old microbial mats in Greenland.

But given that the Earth is about 4.5 billion years old, critics of these discoveries argue, the changes in Earth’s geology over billions of years can sometimes mimic the appearances of lifeforms. Microbiologists therefore need to prove that the older lifeforms did indeed exist by comparing the older fossils to much younger and better-verified examples of life. Researchers must also attempt to verify markings by life against the chemistry in the rocks, although again this can be altered by rock deformation over time.

Baucon is a member of ROSAE, an Italian acronym that in English stands for Organism-Sediment Relationships in Extreme Environments. It’s a scientific project that looks at how organisms and sediments interact in so-called “extreme environments,” such as the deep sea.

In this latest study, Baucon and his colleagues attempt to explain the best way to find extra-terrestrial traces. One method could be looking for “meandering” trails and burrows, which is an efficient way for microorganisms to look for food. Rather than making straight lines in an environment or repeatedly crossing a surface, the meandering allows a creature to search for food without exerting too much energy.

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