NASA's Interstellar Boundary Explorer (IBEX), a $169 million spacecraft has discovered what many scientists surmised; the sun has a comet-like tail. The less than 20 foot square craft, displayed the tail which couldn't be seen before because it doesn't shine, nor does it reflect light. Is the sun a comet?

No, it is a star. Both stars and comets have tails, which can usually be seen through a telescope. Our sun was not that easy.

"By examining the neutral atoms, IBEX made the first observations of the heliotail. Many models have suggested the heliotail might be like this or like that, but we've had no observations. We always drew pictures where the tail of the heliosphere just disappears off the page, since we couldn't even speculate about what it really looked like," said David McComas, lead author on the research and principal investigator for IBEX at Southwest Research Institute in San Antonio, Texas.

A Stradivarius is among the most coveted items in the world, considered to be the best-stringed instrument ever created. The violins, violas and cellos produced by the Stradivari family during the 17th and 18th centuries are prized for their remarkable sound and incredible craftsmanship, and a new study explores the possible techniques used by Antonio Stradivari.

A Stradivarius in pristine condition can fetch millions of dollars. In 2011, a Stradivarius violin made in 1721, named Lady Blunt after Lord Byron's granddaughter, Lady Ann Blunt, was sold at a charity auction for $15.9 million. The money collected during the auction went to Japanese earthquake relief funds.

Approximately 600 string instruments made by Stradivari are still known to exist, according to the Wall Street Journal, and a new study using several diagnostic techniques examined a Stradivarius to unlock the mystery of what techniques and materials were used to create the world's best violins.

Using echolocation, dolphins might be able to detect a pregnant woman's developing fetus, some experts say.

Dolphins emit sounds in their environment and listen to the echoes that return - a process that helps them identify the shapes and locations of objects. Doctors use a similar technique to image a developing human baby. Both involve ultrasound - high-pitched pulses of sound above the range of human hearing.

"I think it's extremely plausible [dolphins] would be able to detect a fetus," said Lori Marino, a neuroscientist at Emory University in Atlanta who studies cetacean intelligence. However, "you'd have to really do a well-controlled study to make a definitive statement," she cautioned.

An airborne geophysical survey mapping mineral resources in the Midwest has confirmed that a 470-million-year-old impact crater nearly five times the size of Barringer (Meteor) Crater in Arizona lies buried several hundred meters beneath the town of Decorah, Iowa.

The crater's existence was first hypothesized in 2008 when geologists examining cuttings from water wells drilled near the town were surprised to find evidence of a previously unknown shale deposit. When geologist Robert McKay from the Iowa Geological Survey investigated further, he found something even more surprising: The shale deposit was nearly a perfect circle, roughly 5.5 kilometers across. Further analysis of sub-shale breccias by Bevan French, a geologist at the Smithsonian's National Museum of Natural History, revealed shocked quartz - a telltale sign of an impact. Together, the evidence added up to an exciting possibility: the existence of a previously unknown impact crater in the Midwest.

Earlier this year, more evidence accumulated when scientists at the U.S. Geological Survey (USGS) and the Iowa and Minnesota Geological Surveys conducted a high-resolution geophysical survey of the region to assess water resources and mineral resources. They were specifically mapping the Northeast Iowa Igneous Intrusive complex, which lies in the Midcontinent Rift System that formed about 1.1 billion years ago, and may contain valuable copper, nickel and platinum group metal resources.

Periodic wobbles in Earth's core change the length of a day every 5.9 years, according to a study published today (July 10) in the journal Nature.

Teasing out this subtle cycle, which subtracts and adds mere milliseconds to each day, also revealed a match between abrupt changes in the length of day and Earth's magnetic field. During these short-lived lurches in the magnetic field intensity, events called geomagnetic jerks, Earth's day also shifts by 0.1 millisecond, the researchers report. Since 1969, scientists have detected 10 geomagnetic jerks lasting less than a year.

Seemingly negligible, these fleeting variations are mighty to those who study the planet and its core. All of a sudden, a planet changes its spin like a figure skater open or closing her arms. The rotational effect helps scientists understand what's happening inside the Earth's core. Shifts in the magnetic field also provide clues to the inaccessible iron core. But their source remains a mystery.

Lead study author Richard Holme suspects a shimmy in the solid inner core that drives the 5.9-year cycle, transferring angular momentum to the outer core. But no one knows what causes geomagnetic jerks.

"I have no clue," said Holme, lead study author and a geophysicist at the University of Liverpool in the U.K. "Something is happening at the core-mantle boundary, because you're seeing the geomagnetic and the rotational effect at the same time, but we don't know what's going on," Holme told LiveScience's OurAmazingPlanet.

US researchers test brains of male and female rats in stressful situations

Females showed no impairment - males struggled with short-term memory

Study finds oestrogen can help block the detrimental effects of stress

Multi-tasking mothers have known it for years - women are better at coping with stress than men.

Now scientists believe they can tell them why.

It's all down to the protective effect of oestrogen, which appears to 'block' the negative effects of stress on the brain.

In a US study, scientists put male and female rats through tasks that mimicked challenging experiences humans often face, such as those causing frustration and feelings of being under pressure.

The female rats showed no impairment in their ability to recognise objects they had previously been shown, said study leader Dr Zhen Yan, while the male rats struggled with their short-term memory.

An inability to remember a familiar object indicates a disturbance in the part of the brain that controls working memory, attention, decision-making and other high-level 'executive' processes.

Antimatter has been detected in solar flares via microwave and magnetic-field data, according to a presentation by NJIT Research Professor of Physics Gregory D. Fleishman and two co-researchers at the 44th meeting of the American Astronomical Society's Solar Physics Division. This research sheds light on the puzzling strong asymmetry between matter and antimatter by gathering data on a very large scale using the Sun as a laboratory.

While antiparticles can be created and then detected with costly and complex particle-accelerator experiments, such particles are otherwise very difficult to study. However, Fleishman and the two co-researchers have reported the first remote detection of relativistic antiparticles - positrons - produced in nuclear interactions of accelerated ions in solar flares through the analysis of readily available microwave and magnetic-field data obtained from solar-dedicated facilities and spacecraft. That such particles are created in solar flares is not a surprise, but this is the first time their immediate effects have been detected.

The results of this research have far-reaching implications for gaining valuable knowledge through remote detection of relativistic antiparticles at the Sun and, potentially, other astrophysical objects by means of radio-telescope observations. The ability to detect these antiparticles in an astrophysical source promises to enhance our understanding of the basic structure of matter and high-energy processes such as solar flares, which regularly have a widespread and disruptive terrestrial impact, but also offer a natural laboratory to address the most fundamental mysteries of the universe we live in.

The latest details from the investigations into the crash of Asiana flight 214 in San Francisco indicate that the jet was flying dangerously slow before it hit the ground. While the NTSB sorts out whether this was pilot error or not, DNews wondered, Would an autonomous piece of computer hardware and software have done better?

The short answer is probably, but that doesn't mean we should hand over control to computers altogether.

Although the technology giving jets the ability to land themselves has been around for decades, it's been limited to the military.

"When I was flying the F/A-18 Hornet, the level of automation made me step back and reevaluate my life," Missy Cummings, associate professor of aeronautics and astronautics and engineering systems director of the Humans and Automation Laboratory at MIT told DNews.

"The plane landed itself better on the carrier than I ever could."

She was convinced that the days of human pilots were numbered.

It hasn't happened because the technology has not moved into commercial airliners. Contrary to popular assumption, the autopilot systems on passenger jets do not handle take off, fly the plane completely and control the landing. In fact, these systems are designed to carry out orders, such as "maintain this heading" or "stay on this glide path."

A new device that trains the brain to convert sounds into images could someday be used as a non-invasive treatment for blind and partially sighted people, according to researchers at the University of Bath.

Sensory substitution devices (SSDs) aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality.

The device in the current study, dubbed "The vOICe," is a visual-to-auditory SSD that encodes images taken by a camera worn by the user into "soundscapes," allowing experienced users to extract information about their surroundings to construct an image in their mind.

The researchers, led by Dr. Michael Proulx from the University's Department of Psychology, examined how blindfolded sighted participants responded to an eye test using the device. The participants were asked to perform a standard eye chart test known as the Snellen Tumbling E test, which asked participants to view the letter E turned in four different directions and in various sizes.

Normal, best-corrected visual acuity is considered 20/20, calculated in terms of the distance (in feet) and the size of the E on the eye chart.

A meteor hitting the Earth 12,800 years ago released toxic gases into the air and blocked out the sun causing temperatures to plummet and plants to die

Some species managed to adapt but the woolly mammoth died out

A giant meteor was probably responsible for wiping out the woolly mammoth, scientists believe.

It has long been thought that hunting was the cause of the creatures' extinction, but researchers have now revised their opinion.

They believe a huge meteor smashing through the Earth's atmosphere broke up into ten million tonnes of fiery fragments, scattering over four continents.

These fragments are thought to have released toxic gas which poisoned the air and blacked out the sun, causing temperatures to plummet, plants to die and landscapes to alter forever.