* A study by the University of Chicago says a cosmic impact is the best explanation for the 'Big Freeze' 12,800 years ago

* They say evidence for this comes from nanodiamonds scattered across 11 countries that could only have come from space

* The material is found in a thin layer just a few metres below the surface

* And they also formed at temperatures in excess of 2,200°C (4,000°F)

* This suggests they were likely created by a major impact event

* Several other theories have been suggested for this Younger Dryas period nearly 13,000 years ago, including wildfires and a solar flare

* But this latest evidence suggests a cosmic impact is the best theory

Around 12,800 years ago Earth was plunged into a 'Big Freeze', resulting in the extinction of many species. What caused this event, however, is not known.

One theory is that Earth was struck by a comet or asteroid at the time and now new research supporting the theory has been released.

By studying nanodiamonds scattered across Europe, North America and South America, the researchers say the impact theory is right.

Less than two months after it first began repeatedly scanning the sky, the ESA's Gaia space observatory has discovered its first supernova - a powerful stellar explosion that had occurred in a distant galaxy located some 500 million light-years from Earth, the agency announced on Friday.

According to the ESA, the supernova was located during a sudden rise in the galaxy's brightness that occurred between two Gaia observations made a month apart. This anomalous spike in light was observed by a team of astronomers during a routine sky survey on August 30, and the supernova was given the name Gaia14aaa.

Since beginning its scientific work on July 25, Gaia has been repeatedly scanning the sky in order to examine a catalogue of nearly one billion stars an average of 70 times over the next five years. Dr. Simon Hodgkin from the Institute of Astronomy in Cambridge explained that there were many benefits to this approach.

"This kind of repeated survey comes in handy for studying the changeable nature of the sky," said Dr. Hodgkin, a member of Gaia's Science Alert Team. "As Gaia goes back to each patch of the sky over and over, we have a chance to spot thousands of 'guest stars' on the celestial tapestry. These transient sources can be signposts to some of the most powerful phenomena in the Universe, like this supernova."

A device that uses magnets to extract bacteria, fungi and toxins from blood could one day throw a lifeline to patients with sepsis and other infections, researchers say.

They say the external gadget - tested so far in rats but not yet humans - might also eventually be modified to strip Ebola and other viruses from blood.

The device was inspired by the spleen, which can continuously remove pathogens and toxins from blood without first identifying the infectious agent.

Dubbed a 'bio-spleen', the invention uses magnetic nanobeads coated with a genetically-engineered human blood protein called mannose-binding lectin (MBL).

The MBL binds to pathogens and toxins, which can then be "pulled out" with a magnet, the developers wrote in the journal Nature Medicine.

The bio-spleen was developed to treat sepsis, or blood infection, which affects 18 million people in the world every year, with a 30-50 per cent mortality rate.

The microbes that cause it are often resistant to antibiotics, and spread fast.

Understanding the origin of life is perhaps the most important outstanding problem in science. Just where did life begin, what conditions does it need and how likely is it to emerge from pre-biotic soups elsewhere in the universe are questions that occupy a great many researchers.

Although fascinating questions, they are particularly hard to formulate in ways that are amenable to scientific investigation. Most research focuses on life-bearing molecules and self-supporting, or autocatalytic, chemistries. But even then, it is hard to agree even on a definition of life. So it is no surprise that progress is slow.

Today, Christoph Adami at Michigan State University in East Lansing sidesteps many of these problems by analysing the origin of life from an entirely different point of view. The basis for Adami's new approach is the idea that life is fundamentally a phenomenon of information. This allows Adami to ignore all the messy details of chemistry and instead consider life's most basic properties as ones determined by the nature of information and the laws of physics that govern it.

Four Earth-facing CME's heading our way

Yesterday I talked about black hole thermodynamics, specifically how you can write the laws of thermodynamics as laws about black holes. Central to the idea of thermodynamics is the property of entropy, which can be related to the amount of physical information a system has.

For classical black holes, this is a problem, because if you toss an object into such a black hole, the object (and all its physical information) is lost forever. It is as if the information of the object was erased, which would violate the basic principle that information cannot be destroyed. Now you might argue that being trapped is not the same thing as being destroyed, but for information it is. If you cannot recover the information, then it has been destroyed.

So it would seem that black holes "eat" information, even though the laws of thermodynamics say that shouldn't be possible. This is known as the black hole information paradox.

A giant fossil, unearthed in the Sahara desert, has given scientists an unprecedented look at the largest-known carnivorous dinosaur: Spinosaurus.

The 95-million-year-old remains confirm a long-held theory: that this is the first-known swimming dinosaur. Scientists say the beast had flat, paddle-like feet and nostrils on top of its crocodilian head that would allow it to submerge with ease.The research is published in the journal Science.

Lead author Nizar Ibrahim, a palaeontologist from the University of Chicago, said: "It is a really bizarre dinosaur - there's no real blueprint for it. It has a long neck, a long trunk, a long tail, a 7ft (2m) sail on its back and a snout like a crocodile. And when we look at the body proportions, the animal was clearly not as agile on land as other dinosaurs were, so I think it spent a substantial amount of time in the water."

The team says that Spinosaurus was a fearsome beast. The researchers say that, at more than 15m (50ft) from nose to tail, it was potentially the largest of all the carnivorous dinosaurs - bigger even than the mighty Tyrannosaurus rex.

In the typical textbook picture, volcanoes, such as those that are forming the Hawaiian islands, erupt when magma gushes out as narrow jets from deep inside Earth. But that picture is wrong, according to a new study from researchers who conclude that seismology data are now confirming that such narrow jets don't actually exist.

In the typical textbook picture, volcanoes, such as those that are forming the Hawaiian islands, erupt when magma gushes out as narrow jets from deep inside Earth. But that picture is wrong, according to a new study from researchers at Caltech and the University of Miami in Florida.

New seismology data are now confirming that such narrow jets don't actually exist, says Don Anderson, the Eleanor and John R. McMillian Professor of Geophysics, Emeritus, at Caltech. In fact, he adds, basic physics doesn't support the presence of these jets, called mantle plumes, and the new results corroborate those fundamental ideas.

"Mantle plumes have never had a sound physical or logical basis," Anderson says. "They are akin to Rudyard Kipling's Just So Stories about how giraffes got their long necks."

Anderson and James Natland, a professor emeritus of marine geology and geophysics at the University of Miami, describe their analysis online in the September 8 issue of the Proceedings of the National Academy of Sciences.

According to current mantle-plume theory, Anderson explains, heat from Earth's core somehow generates narrow jets of hot magma that gush through the mantle and to the surface. The jets act as pipes that transfer heat from the core, and how exactly they're created isn't clear, he says. But they have been assumed to exist, originating near where Earth's core meets the mantle, almost 3,000 kilometers underground -- nearly halfway to the planet's center. The jets are theorized to be no more than about 300 kilometers wide, and when they reach the surface, they produce hot spots.

While the top of the mantle is a sort of fluid sludge, the uppermost layer is rigid rock, broken up into plates that float on the magma-bearing layers. Magma from the mantle beneath the plates bursts through the plate to create volcanoes. As the plates drift across the hot spots, a chain of volcanoes forms -- such as the island chains of Hawaii and Samoa.

Street lights will be switched off in hundreds of towns and villages across France to allow people to enjoy the clear night skies in the Jour de la Nuit on September 20.

The event, organised by the group Agir pour l'Environnement, aims to show how urban light pollution is spoiling people's lives and biodiversity and there will be events ranging from starlit horse rides in Peone, Alpes-Maritimes to a guided observation of the night sky at Ouézy, Calvados.

Many cities, towns and villages will be switching off the bulk of their street lights so that people can better view the stars, planets and the waning Moon. However, there will also be nature events to observe the animals that only come out when dusk falls, such as deer, bats and some butterflies and moths.

Held on the autumn equinox, when the Sun shines directly over the Equator and the days and nights are equal in each hemisphere, it marks the start of autumn in the northern hemisphere and spring in the south.

Developers of artificial micro-humans, or 'mini GM humans,' are hoping to release their technology on the market by 2017.

No this isn't a sci-fi joke. Scientists are developing artificial humans in the same vein as GM plants with the hope that these creations will replace the need for using animals in laboratory testing.

Artificial humans will be 'farmed' with interacting organs that can be used in drug tests, speeding up the process of FDA and other government regulatory approvals, and supposedly without damaging rats or other animals currently used in laboratories.

The GM humans will contain smartphone-sized microchips that will be programmed to replicate up to 10 major human organs.

Each GM human will be tiny - roughly the size of a microchip itself, simulating the response of humans to substances inhaled, absorbed in the blood, or exposed to in the intestinal tract.

Early versions comprising an artificial kidney, heart, lung or gut are already being used by the cosmetic industry and to observe the use of chemical drugs on non-GMO humans.