Scientists have discovered a meteorite weighing over 30 tonnes in northern Argentina. The meteorite was found in the town of Gancedo, 1,085 km north of capital Buenos Aires, Mario Vesconi, president of the Astronomy Association of Chaco, said on Monday.

"While we hoped for weights above what had been registered, we did not expect it to exceed 30 tons," Vesconi said, adding that "the size and weight surprised us", Xinhua news agency reported.

"It was in Campo del Cielo, where a shower of metallic meteorites fell around 4,000 years ago," Vesconi added.

The meteorite will be weighed again to ensure an accurate measurement.

The largest meteorite ever found is called Hoba, weighing 66 tonnes in Namibia, Africa.

In the summer of 2014, Mardi McNeil was an undergraduate student at the Queensland University of Technology. She was spending the summer helping a team of scientists with a big research project: mapping the ocean floor around the Great Barrier Reef.

McNeil's job was to map the extent and structure of bioherms, mounds of ancient calcified algae, scattered outside the Great Barrier Reef 60 to 100 feet below the surface. Scientists in the 80s had documented the bioherms using acoustic sound waves, but no one had re-visited them with modern technology. So McNeil used lidar data (a mapping technique that measures distance with lasers) collected by the Australian navy to create high-resolution 3D renderings of the ocean floor.

But as soon as she started looking through the images she made, McNeil knew she'd found something big.

A study by Japanese researchers has linked the timing of large earthquakes with tidal stresses around the time of a new or full moon.
Research conducted by University of Tokyo academics and published in the journal Nature Geoscience examined the tidal activity prior to large earthquakes around the world during the last 20 years.

The study looked at earthquakes of magnitude 5.5 or higher, including the magnitude 9 earthquake that struck Japan in March 2011, triggering a devastating tsunami.

It said some of the biggest quakes occurred when tidal stresses were high, at spring tides, just after a new or full moon.

Victoria University geophysicist John Townend said the research did not mean people could predict when and where a big earthquake was likely to strike.

In 2014, the incorporation of two artificial letters of genetic code into the DNA of Escherichia coli gave the bacteria the distinction of becoming the world's first stable semisynthetic organism.

The modification was intended to illustrate the possibility of enabling organisms to incorporate and replicate an artificial base pair for the future biosynthesis of novel proteins. But now in a new study, scientists have discovered that the artificial base pair has an unintended consequence on living cells: phototoxicity. The new results show that the artificial base pair makes living cells more susceptible to damage from low doses of sunlight and standard fluorescent light bulbs, leading to a significant decrease in cell survival and growth.

The study, titled "Unintended Consequences of Expanding the Genetic Alphabet," is published in a recent issue of the Journal of the American Chemical Society by a team of researchers led by Carlos E. Crespo-Hernández from Case Western Reserve University, along with coauthors from Case Western and Columbia University.

"There is currently an ongoing quest to genetically modify living cells and organisms with different purposes," Crespo-Hernández told Phys.org. "Our work clearly cautions scientists that care must be exercised when efforts are made to expand the genetic alphabet, especially if the synthetic organisms may be exposed to light— a fact that has been hitherto overlooked."

Engineers in San Francisco have come up with an amazing invention: a fish 1/100 the size of a grain of sand that could carry drugs to specific areas of the body, be used for invasive surgeries, and even single cell manipulation.

The nanofish is made of gold and nickel parts linked by silver hinges. The "head" and "tail" are made of gold, while the"body" is made of nickel. Each segment is about 800 nanometers long (a nanometer is one billionth of a meter), The New Scientist media outlet reported.

How does it work?

An oscillating magnetic field is applied to make the nickel parts move from side to side, in turn swinging the head and tail and creating movement - essentially, swimming. The magnetic field can also be used to set a specific direction for the nanofish.

Chinese scientists have proposed a new theory that explains why humans are so much more intelligent than animals even though our brains are often much smaller than those of other species. Researchers at the Wuhan Institute of Neuroscience and Neuro-engineering have previously carried out studies backing the theory that the brain not only processes and passes on information not only through electrical and chemical signals, but also with photons of light.

Now, their latest study, the Wuhan researchers, led by professor Dai Jiapei suggested two years ago that neurons, the nerve cells in the brain that transmit information, emit extremely "lights," photons, stimulated by a chemical called glutamate and detectable only with the most sensitive equipment, but capable of transmission along brain fibers and circuits. The key finding is that human brains are able to create information-relaying photons using much less energy, enabling homo sapiens to operate more speedily and efficiently than brains of other species

Two dolphins have been recorded having a conversation for the first time after scientists developed an underwater microphone which could distinguish the animals' different "voices".

Researchers have known for decades that the mammals had an advanced form of communication, using distinctive clicks and whistles to show they are excited, happy, stressed or separated from the group.

But scientists have now shown that dolphins alter the volume and frequency of pulsed clicks to form individual "words" which they string together into sentences in much the same way that humans speak.

Researchers at the Karadag Nature Reserve, in Feodosia, Russia, recorded two Black Sea bottlenose dolphins, called Yasha and Yana, talking to each other in a pool. They found that each dolphin would listen to a sentence of pulses without interruption, before replying.

NASA's bold mission to bring pieces of an asteroid down to Earth has taken flight.

The agency's OSIRIS-REx spacecraft lifted off from Cape Canaveral Air Force Station here today (Sept. 8) at 7:05 p.m. EDT (2305 GMT), riding a United Launch Alliance Atlas V rocket into an evening sky suffused with golden light.

"Liftoff for OSIRIS-Rex, its seven-year mission to boldly go to the asteroid Bennu and back," NASA spokesman Mike Curie said during a live launch broadcast in an apparent nod to "Star Trek," which celebrated its 50th anniversary on Thursday.

If everything goes according to plan, OSIRIS-REx will rendezvous with a 1,640-foot-wide (500 meters) asteroid named Bennu in August 2018, snag some dirt and pebbles off the space rock two years later, and deliver this cosmic sample to Earth in September 2023.


"Sample return is really at the forefront of planetary exploration," OSIRIS-REx principal investigator Dante Lauretta said during a prelaunch news conference Tuesday (Sept. 6). "Not only are we going to get this material into our laboratories for precise chemical analyses that can't be duplicated by spacecraft instruments, but this is [also] going to be a treasure trove of information and material for scientists yet to come."

"It's amazing, shocking," said Glyn Collinson, a scientist at NASA's Goddard Space Flight Center on June 20th. "We never dreamt an electric wind could be so powerful that it can suck oxygen right out of an atmosphere into space. This is something that has to be on the checklist when we go looking for habitable planets around other stars."

Venus has an "electric wind" strong enough to remove the components of water from its upper atmosphere, which may have played a significant role in stripping Earth's twin planet of its oceans, according to new results from ESA's (European Space Agency) Venus Express mission by NASA-funded researchers.

Taking the electric wind into account will also help astronomers improve estimates of the size and location of habitable zones around other stars. These are areas where the temperature could allow liquid water to exist on the surface of alien worlds, making them places where life might be found. Some stars emit more ultraviolet light than the sun, so if this creates stronger electric winds in any planets orbiting them, the habitable zone around such stars may be farther away and narrower than thought.

Venus is in many ways the most like Earth in terms of its size and gravity, and there's evidence that it once had oceans worth of water in its distant past. However, with surface temperatures around 860 F (460 C), any oceans would have long since boiled away to steam and Venus is uninhabitable today.

Yet Venus' thick atmosphere, about 100 times the pressure of Earth's, has 10,000 to 100,000 times less water than Earth's atmosphere. Something had to remove all that steam, and the current thinking is that much of the early steam dissociated to hydrogen and oxygen: the light hydrogen escaped, while the oxygen oxidized rocks over billions of years.

Also the solar wind -- a million-mile-per-hour stream of electrically conducting gas blowing from the sun -- could have slowly but surely eroded the remainder of an ocean's worth of oxygen and water from Venus' upper atmosphere.

"We found that the electric wind, which people thought was just one small cog in a big machine, is in fact this big monster that's capable of sucking the water from Venus by itself," said Collinson.

Just as every planet has a gravity field, it is believed that every planet with an atmosphere is also surrounded by a weak electric field. While the force of gravity is trying to hold the atmosphere on the planet, the electric force (the same force that sticks laundry together in a drier and pushes electricity through wires) can help to push the upper layers of the atmosphere off into space. At Venus, the much faster hydrogen escapes easily, but this electric field is so strong that it can accelerate even the heavier electrically charged component of water -- oxygen ions -- to speeds fast enough to escape the planet's gravity. When water molecules rise into the upper atmosphere, sunlight breaks the water into hydrogen and oxygen ions, which are then carried away by the electric field.

Turns out bacteria may transfer to candy that has fallen on the floor no matter how fast you pick it up.

Rutgers researchers have disproven the widely accepted notion that it's OK to scoop up food and eat it within a "safe" five-second window. Donald Schaffner, professor and extension specialist in food science, found that moisture, type of surface and contact time all contribute to cross-contamination. In some instances, the transfer begins in less than one second. Their findings appear online in the American Society for Microbiology's journal, Applied and Environmental Microbiology.

"The popular notion of the 'five-second rule' is that food dropped on the floor, but picked up quickly, is safe to eat because bacteria need time to transfer," Schaffner said, adding that while the pop culture "rule" has been featured by at least two TV programs, research in peer-reviewed journals is limited.