Our sun may seem pretty impressive: 330,000 times as massive as Earth, it accounts for 99.86 percent of the Solar System's total mass; it generates about 400 trillion trillion watts of power per second; and it has a surface temperature of about 10,000 degrees Celsius. Yet for a star, it's a lightweight.

The real cosmic behemoths are Wolf-Rayet stars, which are more than 20 times as massive as the Sun and at least five times as hot. Because these stars are relatively rare and often obscured, scientists don't know much about how they form, live and die. But this is changing, thanks to an innovative sky survey called the intermediate Palomar Transient Factory (iPTF), which uses resources at the National Energy Research Scientific Computing Center (NERSC) and Energy Sciences Network (ESnet), both located at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), to expose fleeting cosmic events such as supernovae.

For the first time ever, scientists have direct confirmation that a Wolf-Rayet star -- sitting 360 million light years away in the Bootes constellation -- died in a violent explosion known as a Type IIb supernova. Using the iPTF pipeline, researchers at Israel's Weizmann Institute of Science led by Avishay Gal-Yam caught supernova SN 2013cu within hours of its explosion. They then triggered ground- and space-based telescopes to observe the event approximately 5.7 hours and 15 hours after it self-destructed. These observations are providing valuable insights into the life and death of the progenitor Wolf-Rayet.

A supergiant star exploded 23.5 million years ago in one of the largest and brightest nearby galaxies. This spring we finally got the news. In April, the Katzman Automatic Imaging Telescope (KAIT) as part of the Lick Observatory Supernova Search, photographed a faint "new star" very close to the bright core of M106, a 9th magnitude galaxy in Canes Venatici the Hunting Dogs.

Models of how the Earth's mantle works may need to change, thanks to two new studies that recreate the extreme conditions just above the planet's core.

The deep mantle, a region that lies 416 to 1,800 miles (670 to 2,900 kilometers) below the Earth's surface, is impossible to reach and hard to "see" clearly with seismic signals. The little scientists do know about the mantle comes from earthquake waves, which speed up and slow down as they travel through different rock layers inside the Earth. The deepest part of the mantle has weird blobs and seismic slow zones that have long puzzled scientists. Both new studies offer possible explanations for the strange seismic behavior.

In the studies, researchers mimicked conditions inside the deep mantle with experiments in the laboratory. Teams working independently on different continents shot lasers at tiny specks of rock squeezed between diamond anvils.

One team concluded that scientists had been wrong about the form that a certain rock takes in the deep mantle, which accounts for about half of Earth's volume. The other team found evidence for small amounts of Earth's most common surface rock, basalt, pooling in liquid form at the core-mantle boundary. The findings are published today (May 22) in the journal Science.

"These results are a new step forward in reproducing in the laboratory what is occurring in the very deep mantle," said Denis Andrault, lead author of one of the studies and a scientist at Blaise Pascal University in France.

Facebook's mobile app just grew a keen sense of hearing. Starting Wednesday, the app has the ability to recognize music and television shows playing in the vicinity of users.

The feature is designed to make it easier for users to share. When users begin to write a post, the Facebook app will offer to include information about music or shows playing in the background.

"We want to help people tell better stories," said Aryeh Selekman, the product manager who led the development of the feature. "I hope there are people who love the feature and post more."

If Facebook users share more about themselves, that can boost the value of ads targeted at some of its 1.28 billion users.

The audio-recognition feature works similar to the app Shazam, which also can identify music and television programming using the built-in microphones in mobile phones.

If you've noticed the cost of a cup of coffee at your local shop has been inching up lately, it's because a fungus has decimated Central America's Arabica bean crop. Now the US is stepping in to try to eliminate the deadly coffee rust fungus.

Leaf rust, or la roya in Spanish, is a yellow- and orange-colored, plant-choking fungus that has devastated coffee crops from Peru to Mexico over the past three years, costing $1 billion in damages in Central America in the late harvest season of 2012 alone. The fungus is especially ruinous to the Arabica bean, which is used in higher-end coffees, as it is said to produce better-tasting coffee than the other major commercially grown coffee species. It contains less caffeine but a more robust flavor. Arabica accounts for 75 to 80 percent of the world's coffee production, according to the Coffee Research Institute.

The effects of leaf rust have decimated local economies.

"Big farmers hire fewer workers to pick the ripe coffee cherries that enclose the beans. Smaller farmers go into debt and sell livestock or tools to make up for the lost income. Sales fall at local merchants," the New York Times reported. "Teenagers leave school to work on the farm because their parents can no longer hire outside help. At the very end of the chain are the landless migrant workers who earn just a few dollars a day."

Central America has been particularly hard hit. Four million people there and in southern Mexico rely on coffee for their living, according to the Inter-American Development Bank. In Guatemala, twenty percent of the half-million jobs directly tied to growing coffee have already disappeared, estimated Nils Leporowski, the president of Anacafé, the country's coffee board.

Los Alamos National Laboratory packed 57 barrels of nuclear waste with a type of kitty litter believed to have caused a radiation leak at the federal government's troubled nuclear waste dump, posing a potentially "imminent" and "substantial" threat to public health and the environment, New Mexico officials said Monday.

State Environment Department Secretary Ryan Flynn issued a formal order giving the lab two days to submit a plan for securing the waste containers, many of which are likely stored outdoors on the lab's northern New Mexico campus or at a temporary site in west Texas.

The order says 57 barrels of waste were packed with nitrate salts and organic kitty litter, a combination thought to have caused a heat reaction and radiation release that contaminated 22 workers with low levels of radiation at the Waste Isolation Pilot Plant near Carlsbad in February.

The kitty litter soaks up any liquid before drums of waste are sealed and shipped. Officials are investigating whether a switch from non-organic to organic litter is to blame for the leak.

According to the order, two of those containers are known to be at WIPP. It doesn't say where the rest of the barrels are, but Los Alamos was in the process of transferring the last of thousands of barrels of waste from decades of nuclear bomb making to the underground dump when the leak shuttered the half-mile-deep mine.

Some containers were then transferred to temporary storage at a commercial nuclear waste dump in Andrews, Texas. But all shipments were stopped when investigators earlier this month zeroed in on the Los Alamos container as the likely source of the leak.

"Based on the evidence presented to NMED, the current handling, storage, treatment and transportation of the hazardous nitrate salt bearing waste containers at LANL may present an imminent and substantial endangerment to health or the environment," the order signed by Flynn states.

The movement to sell locally sourced, artisanal food and drink has picked up steam in recent years as many consumers demand better quality products with a smaller environmental footprint and traceable pedigree.

But some Dutch researchers are taking this idea a step further, proposing the creation of village-level "meat factories" that would produce unique flavors of artificial beef, pork or chicken, all from a biotech reactor.

The study builds upon work done last year, the so-called "test-tube hamburger" that was created by researchers at the University of Maastrict in the Netherlands and unveiled at a tasting in London.

This latest study by a pair of researchers at Wagenigen University proposes a device that can create meat cells in a metal container - enough to feed a small amount of "cultured beef" each month to a village of 2,650 people.

"We thought it was interesting and most promising to do cultured meat on a small scale," said Cor van der Weele, professor of philosophy who wrote the paper with biotechnology professor Johannes Tamper in the journal Trends in Biotechnology. "A small scale is also good from a biotechnology point of view."

Van der Weele said she was inspired to come up with this alternative to meat because of her concerns over animal welfare, as well as the environmental impact of land used to grow beef cattle.

"Raising small numbers of animals in a village is fine," Van der Weele said. "But the way animals are raised now is not in small amounts but in large scale and factory farms."

"Fairy circles" that form in the arid grasslands of Namibia have baffled scientists for decades. In the latest attempt to explain the cause of these mysterious circular patches, a group of researchers turned to aerial images.

From the aerial images, the scientists discovered that fairy circles are distributed in surprisingly regular patterns, which might rule out the popular theory that termites are the creators.

"The occurrence of such patterning in nature is rather unusual," study researcher Stephan Getzin, of the Helmholtz Centre for Environmental Research (UFZ) in Leipzig, Germany, said in a statement. "There must be particularly strong regulating forces at work." [Image Gallery: Amazing 'Fairy Circles' of the Namib Desert]

Fairy circles are barren patches, typically surrounded by a ring of thriving vegetation. They can grow to be 65 feet (20 meters) in diameter and can linger for as long as 75 years.

For the past several years, scientists have offered up a variety of hypotheses for why these rings form in the arid grasslands transitioning into the Namib Desert. Their explanations have ranged from grass-killing seeps of hydrocarbons to carnivorous ants to termite feeding patterns.

Mitochondria not only come exclusively from an organism's mother, they are the power generators of the cells, creating a source of chemical energy known as ATP or adenosine triphosphate. The amount of mitochondria in a cell is based upon the metabolic requirements of that particular cell and the numbers present may range from only one up into the thousands. Therefore, the more demanding the cell's energy requirements, the more of these so-called cellular power plants are required. While mitochondria are inherited maternally, it is currently unknown as to what exactly causes the destruction of the paternal side.

Paternal mitochondria are not passed on to an organism. They are either prevented from somehow doing so or are simply destroyed before they can be passed on to any offspring. Scientists are currently looking at this phenomenon to try to find both the reason behind this evolutionary enigma and the manner in which it occurs. Recently, Dr. Eli Arama and colleagues from Weizmann Institute have discovered some specialized cellular vesicles which come from the egg to be fertilized. These vesicles not only locate but also actively cause the destruction of the father's paternal mitochondria during the fertilization process.

The team from the Institute's Molecular Genetics Department worked with fruit flies to conduct this study. Past studies to determine the cause of the absence of the father's power cells were undertaken using worms and mice. Unfortunately, the sperm of worms are very different from those of a human, not having the same head or tail structures as mammals. While other studies were preformed on mice, those studies were trying to determine whether the absence was caused by some passive dilution process. The passive dilution theory, however, could not explain why autophagy markers, where vesicles actually engulf the cell's unwanted structures, were still found. It appears that they actually seek out the paternal mitochondria in order to actively destroy them instead of relying on a passive method of dilution.

Going on a first date? The chance that it leads to wedding bells may depend, in part, on how similar his or her DNA is to yours.

New research finds that people tend to pick spouses whose genetic profile shares similarities with their own. The effect is subtle (other similarities, such as similarity in education, have a larger influence), but it's important to understand that mating isn't truly genetically random, researchers report today (May 19) in the journal Proceedings of the National Academy of Sciences.

The genetic effect might even signal or contribute to social inequality, they write. The current U.S. social system might inadvertently sort people by genetics, for example, or contribute to schisms seen at the level of our very DNA.

Picking a partner

When it comes to marriage, the adage "birds of a feather flock together" is more on-point than the idea that opposites attract. Many studies have found that people tend to marry others who are similar to them in education, social class, race and even body weight. The phenomenon is called assortative mating.

The question, according to study leader and University of Colorado research associate Benjamin Domingue, was whether these assortative mating differences are visible at the genetic level.

The researcher analyzed genetic data from 825 non-Hispanic white Americans who participated in the U.S. Health and Retirement Study. They compared the similarity of the DNA of married couples with the similarity of random, non-coupled individuals.

The results, mirrored in a follow-up study with data from the long-running Framingham Heart Study, revealed that married people have more similar DNA segments than random pairs of people.