In the approach to perihelion over the past few weeks, Rosetta has been witnessing growing activity from Comet 67P/Churyumov - Gerasimenko, with one dramatic outburst event proving so powerful that it even pushed away the incoming solar wind.

The comet reaches perihelion on Thursday, the moment in its 6.5-year orbit when it is closest to the Sun. 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.

Although the comet's general activity is expected to peak in the weeks following perihelion, much as the hottest days of summer usually come after the longest days, sudden and unpredictable outbursts can occur at any time - as already seen earlier in the mission.

CBET nr. 4136, issued on 2015, August 11, announces the discovery of a comet (magnitude ~11) by M. Mattiazzo on low-resolution public website hydrogen Lyman-alpha images obtained during Aug. 3 and 4 with the Solar Wind Anisotropies (SWAN) camera on the Solar and Heliospheric Observer (SOHO) spacecraft. The new comet has been designated C/2015 P3 (SWAN).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 13 unfiltered exposures, 15-sec each, obtained remotely on 2015, August 10.4 from Q62 (iTelescope network - Siding Spring) through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer, shows that this object is a comet: sharp central condensation surrounded by bright coma about 1 arcmin in diameter.

Our confirmation image (click on it for a bigger version)
M.P.E.C. 2015-P25 assigns the following very preliminary parabolic orbital elements to comet C/2015 P3: 2015 July 27.26; e= 1.0; Peri. = 131.81; q = 0.71; Incl.= 59.32

Unlike any other life on Earth, these extraordinary bacteria use energy in its purest form - they eat and breathe electrons - and they are everywhere Stick an electrode in the ground, pump electrons down it, and they will come: living cells that eat electricity. We have known bacteria to survive on a variety of energy sources, but none as weird as this. Think of Frankenstein's monster, brought to life by galvanic energy, except these "electric bacteria" are very real and are popping up all over the place.

Unlike any other living thing on Earth, electric bacteria use energy in its purest form - naked electricity in the shape of electrons harvested from rocks and metals. We already knew about two types, Shewanella and Geobacter. Now, biologists are showing that they can entice many more out of rocks and marine mud by tempting them with a bit of electrical juice. Experiments growing bacteria on battery electrodes demonstrate that these novel, mind-boggling forms of life are essentially eating and excreting electricity.

That should not come as a complete surprise, says Kenneth Nealson at the University of Southern California, Los Angeles. We know that life, when you boil it right down, is a flow of electrons: "You eat sugars that have excess electrons, and you breathe in oxygen that willingly takes them." Our cells break down the sugars, and the electrons flow through them in a complex set of chemical reactions until they are passed on to electron-hungry oxygen.

In the process, cells make ATP, a molecule that acts as an energy storage unit for almost all living things. Moving electrons around is a key part of making ATP. "Life's very clever," says Nealson. "It figures out how to suck electrons out of everything we eat and keep them under control." In most living things, the body packages the electrons up into molecules that can safely carry them through the cells until they are dumped on to oxygen.

Researchers who have revealed a highly efficient way that bacteria use toxins to interrupt the immune response say that until now, the trickery of these toxins has been underappreciated in science.

Bacteria harm the body by releasing toxins - proteins that are exceptionally effective poisons. Always targeting essential molecules, toxins typically go after molecules that are either scarce or whose role is to send important signals. In both cases, only a small number of toxins is required to cause damage.

In contrast, some toxins appear to deviate from these strategies by targeting highly abundant proteins.

A new study shows that one toxin linked to cholera and other diseases, which hones in on a popular and plentiful protein target, also disables a scarce molecule - but in a deceptive way. The toxin turns the common protein into poison against the other essential and much less-abundant protein in a process that renders the immune cell useless.

It's important to understand how toxins work because they are key to enabling bacteria to cause disease. With some of the most lethal toxins - those released by the bacteria that cause whooping cough and dysentery, for example - a single molecule of toxin can kill an entire cell.

"It appears that this toxin followed some of the most sophisticated battlefield strategies long before they were invented by humans: It recognizes that to win the war, one doesn't need to kill all the soldiers. All that is needed is to send in a spy to recruit a few soldiers who will betray their own army and neutralize the officers," said Dmitri Kudryashov, assistant professor of chemistry and biochemistry at The Ohio State University and senior author of the study.

"This finding suggests that with other toxins that appear to act on highly abundant structures, it's likely that we don't actually know how they work."

Gravity, one of the four fundamental forces of nature, appears reassuringly constant across the Universe, according to a decades-long study of a distant pulsar. This research helps to answer a long-standing question in cosmology: Is the force of gravity the same everywhere and at all times? The answer, so far, appears to be yes.

Astronomers using the National Science Foundation's (NSF) Green Bank Telescope (GBT) in West Virginia and its Arecibo Observatory in Puerto Rico conducted a 21-year study to precisely measure the steady "tick-tick-tick" of a pulsar known as PSR J1713+0747. This painstaking research produced the best constraint ever of the gravitational constant measured outside of our Solar System.

Pulsars are the rapidly spinning, superdense remains of massive stars that detonated as supernovas. They are detected from Earth by the beams of radio waves that emanate from their magnetic poles and sweep across space as the pulsar rotates. Since they are phenomenally dense and massive, yet comparatively small - a mere 20 - 25 kilometers across - some pulsars are able to maintain their rate of spin with a consistency that rivals the best atomic clocks on Earth. This makes pulsars exceptional cosmic laboratories to study the fundamental nature of space, time, and gravity.

This particular pulsar is approximately 3,750 light-years from Earth. It orbits a companion white dwarf star and is one of the brightest, most stable pulsars known. Previous studies show that it takes about 68 days for the pulsar to orbit its white dwarf companion, meaning they share an uncommonly wide orbit. This separation is essential for the study of gravity because the effect of gravitational radiation - the steady conversion of orbital velocity to gravitational waves as predicted by Einstein - is incredibly small and would have negligible impact on the orbit of the pulsar. A more pronounced orbital change would confound the accuracy of the pulsar timing experiment.

"The uncanny consistency of this stellar remnant offers intriguing evidence that the fundamental force of gravity - the big 'G' of physics - remains rock-solid throughout space," said Weiwei Zhu, an astronomer formerly with the University of British Columbia in Canada and lead author on a study accepted for publication in the Astrophysical Journal. "This is an observation that has important implications in cosmology and some of the fundamental forces of physics."

The Universe is slowly dying according to astronomers who have made a study of the fall in energy levels resulting from the fusion of matter taking place in the nuclear furnaces of the stars of more than 200,000 galaxies.

A wide-spectrum survey of the galaxies has revealed the precise levels of energy generated within an immense segment of space and found that it is only half of what it was 2bn years ago - and that it is continuing to fade.

Previous work had already discovered that the conversion of matter to energy in the cosmos was declining but this is the most detailed survey to date of the sky across a wide range of light wavelengths, astronomers said.

Researchers from the International Centre for Radio Astronomy Research (ICRAR) in Western Australia used seven of the world's most powerful telescopes to observe galaxies at 21 different wavelengths of light, from the far ultraviolet to the far infrared - the most comprehensive audit of the energy output of a nearby part of the Universe.

Initial observations were conducted using the Anglo-Australian Telescope in New South Wales and supporting observations were made by two orbiting space telescopes operated by NASA and another belonging to the European Space Agency, scientists said. The research is part of the Galaxy and Mass Assembly (Gama) project, the largest multi-wavelength survey of space.

Japanese scientists have developed a new pair of shades which protect users from undesired and secretive facial recognition technologies, felt by many to infringe on privacy. Next year one can 'hide' from Big Brother's watchful eye for just $240.

The new "Privacy Visor" developed by Japan's National Institute of Informatics (NII) won't make you invisible but it, will certainly keep you anonymous and protected from automatic facial recognition techniques for the time being, according to its creators.

The trick lies in a series of crafted lenses that reflect, refract and absorb light in different directions and from different angles. The technology renders one's face nearly unrecognizable to the face-detection software available on the market today.

"The Privacy Visor is the world's first product with this technology," said Professor Isao Echizen, who led the research. "We are often told not to unveil our personal information to others, but our faces are also a type of an ID. There should be a way to protect that."

Facebook has a new little-known software that monitors your profile chat and pictures for criminal activity. The software will proceed to alert an employee at the company who will then decide whether to call authorities or not.

The software will monitor individuals who have a 'loose' relationship on social media networks, according to an interview with Facebook Chief Security Officer, Joe Sullivan.

Reuters interview with the security officer explains that Facebook's software focuses on conversations between members who have a loose relationship on the social network. For example, if two users aren't friends, only recently became friends, have no mutual friends, interact with each other very little, have a significant age difference, and/or are located far from each other, the tool pays particular attention.

Astronomers at the 29th International Astronomical Union General Assembly will announce on August 14 the discovery of a new transiting "circumbinary" planet, bringing the number of such known planets into double digits. A circumbinary planet orbits two stars, and like the fictional planet "Tatooine" from Star Wars, this planet has two suns in its sky. The discovery marks an important milestone and comes only four years after the first Kepler circumbinary planet was detected. Once thought to be rare or even impossible, these ten discoveries confirm that such planets are common in our galaxy. The research was recently published in the Astrophysical Journal.

The new planet, known as Kepler-453 b, also presented astronomers with a surprising twist—the tilt of the orbit of the planet rapidly changes, making transits visible only 9 percent of the time. "The detection was a lucky catch for Kepler," said William Welsh, professor of astronomy at San Diego State University and lead author of the study. "Most of the time, transits would not be visible from Earth's vantage point." The change of orientation of the planet's orbital plane, known as precession, brought it into proper alignment halfway through the space telescope's lifetime, allowing three transits to be observed before the end of the mission. "The low probability for witnessing transits means that for every system like Kepler-453 we see, there are likely to be 11 times as many that we don't see," added co-author Jerome Orosz, also a professor of astronomy at San Diego State University. The precession period is estimated to be approximately 103 years. The next set of transits won't be visible again until the year 2066.

It is often said that the eyes are a window to the soul and now research suggests that their shape can be used to distinguish between predator and prey in the animal kingdom.

A study by the University of California and Durham University found that animals with pupils shaped like vertical slits are more likely to be ambush-predator species such as cats and crocodiles.

Meanwhile, plant-eating "prey" species such as sheep and goats tend to have horizontal, elongated "letterbox" pupils. And circular pupils are linked to "active foragers" - animals that chase down their prey rather than creeping up and ambushing them.

The analysis of 214 species, which appears in the journal Science Advances, suggests that there are good evolutionary reasons for these differing optical designs.

Tests showed that eyes with horizontal-slit pupils offered an expanded field of view. Located on each side of the prey animal's head, they provide a panoramic visual display that improves its chance of spotting approaching danger.

The slits also have the added advantage of limiting the amount of dazzling light from the sun, making it easier to see the ground.

"The first key visual requirement for these animals is to detect approaching predators, which usually come on the ground," said the report's lead scientist, Professor Martin Banks of the University of California at Berkeley. "They need to see panoramically on the ground with minimal blind spots. Once they do detect a predator, they need to see where they are running. They have to jump over things."

The research found that vertical slits, meanwhile, give the predator the improved depth of field and the ability to judge distances that helps them secure their prey.