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Not many of us like to consider the complex chemical processes that begin after we die. But new research into the chemical odors released by decomposing bodies is providing forensic scientists with a powerful tool to determine how long a person has been dead, a term known as post-mortem interval (PMI). Understanding this ‘smell of death’ also helps scientists understand how sniffer dogs discover buried disaster victims and locate clandestine graves....

During the height of the Cold War, U.S. spy satellites collected secret images as they circled the Earth. Today, those images are helping scientists track the effects of climate change. A new analysis of declassified spy imagery, published yesterday in Science Advances, has revealed some alarming trends in one of the world’s iciest regions. Glaciers in the Himalayas are melting twice as fast now as they were before 2000. And scientists suggest that rising temperatures are likely to blame....

Once thought to have been born in isolation on the cold outskirts of our solar system, new evidence indicates that comets may actually have had company when they formed. Recent analysis of comet dust, the first ever collected and brought back to Earth, revealed a mix of particles from the region beyond Neptune as well as the area closer to the sun. The finding is significant because it indicates that more mixing of ingredients occurred when the solar system was forming than scientists originally believed....

Women may have a more subtle way of telling men “no” than anyone imagined. Chemical cues in their tears signal that they are not interested in romantic ac­­tivities, according to a study published online January 6 in Science. Crying reveals a person’s mood, but its evolutionary origins have long been a mystery. Because emotional tears have a different chemical makeup than those evoked by irritants in the eye, cognitive neuroscientist Noam Sobel of the Weizmann Institute of Science in Rehovot, Israel, wondered whether emotional tears relay chemical mes­sages to others....

In 1945 Alexander Fleming, the man who discovered penicillin, warned that overuse of his miracle drug could make bacteria immune to it. He was right—and not just about penicillin: the Centers for Disease Control and Prevention has estimated that antibiotic-resistant bacteria infect more than two million people a year, at least 23,000 of whom die. A significant part of that overuse, the cdc says, involves feeding the drugs to the animals we eat....

SYRACUSE, N.Y.—The financial crisis and subsequent global recession have led to much soul-searching among economists, the vast majority of whom never saw it coming. But were their assumptions and models wrong only because of minor errors or because today’s dominant economic thinking violates the laws of physics? A small but growing group of academics believe the latter is true, and they are out to prove it. These thinkers say that the neoclassical mantra of constant economic growth is ignoring the world’s diminishing supply of energy at humanity’s peril, failing to take account of the principle of net energy return on investment....

Life is filled with unexpected moments of beauty, something those on a lab bench know just as well as any poet. The third annual Science Is Beautiful competition at Charles University in Prague allowed students and faculty to share these moments through photographs, digital imagery and illustration. “What is beautiful about science?” asked Bohuslav Gaš, dean of the university’s Faculty of Science, which organized the competition, during his introductory speech at the exhibition of winning entries....

Dear EarthTalk: Do zoos have serious programs to save endangered species, besides putting a few captives on display for everyone to see? – Kelly Traw, Seattle, WA Most zoos are not only great places to get up close to wildlife, but many are also doing their part to bolster dwindling populations of animals still living free in the wild. To wit, dozens of zoos across North America participate in the Association of Zoos and Aquarium’s (AZA’s) Species Survival Plan (SSP) Program, which aims to manage the breeding of specific endangered species in order to help maintain healthy and self-sustaining populations that are both genetically diverse and demographically stable....

In the June Scientific American Australian entomologist Scott O’Neill writes about a novel method to control mosquito-borne disease. By infecting disease-carrying mosquitoes with a common natural bacterium called Wolbachia, his team hopes to reduce dengue (aka breakbone) fever infections in humans. Bugs infected with the microbe are unable to spread dengue, a painful disease that infects 390 million people every year. There are few other options. Without a vaccine against dengue, our main defense has been slashing mosquito populations with insecticides....

Evidence for a new geologic epoch continues to accumulate, like layers of sediment that over time harden into strata. Although those who study the branch of geology known as stratigraphy—the study of those strata and their resolution into Earth’s vast geologic time scale—will continue to debate the idea of the Anthropocene for what may seem like eons, the record in the rock continues to pile up. “This Anthropocene signal is global, it is sharp and all the signs are big,” argues geologist Jan Zalasiewicz of Leicester University, chair of the group tasked with making a formal recommendation on the potential for a human-made, future-looking epoch....

For the past year, space probe Hayabusa2 has pelted asteroid Ryugu with bouncing probes, shot a bullet at it, and taken a bite of it—all for science. But now, the mission has performed its most daring manoeuvre yet: it dropped an explosive on the surface of the asteroid to create a small crater. If the explosion went as planned—the mission team are yet to confirm the detonation—it will expose some of the asteroid’s subsurface layers that the probe will gather during a later touchdown....

Treating dairy cows and other farm animals with antibiotics and then laying their manure in soil can cause the bacteria in the dirt to grow resistant to the drugs. But a study now suggests that the manure itself could be contributing to resistance, even when it comes from cows that are free of antibiotics. The mechanism at work is not yet clear, but the finding — published on October 6 in Proceedings of the National Academy of Sciences — suggests a complex link between antibiotic use in agriculture and resistance in human pathogens....

Ceres, the largest dwarf planet in the inner Solar System, is spurting water into space. The most likely sources of the sporadic vapor plumes, which astronomers have observed using an orbiting telescope, are two relatively dark areas in the orb’s mid-latitude regions. What triggers the wisps is not yet clear, but a NASA mission scheduled to arrive at Ceres early next year could solve the puzzle — and help to explain how water has been distributed throughout the solar system, including Earth....

The number of Americans with diabetes doubled between 1980 and 2003 and more than 13 million are currently diagnosed with the disease. Being overweight or obese has long been recognized as a risk factor for type 2 diabetes. Now the results of a new study are clarifying the nature of the link between weight and diabetes. According to a report published today in the journal Nature, a protein released by fat tissue causes insulin resistance in mice....

Scientists have discovered a dangerous and highly transmissible form of multidrug-resistant bacteria lurking on a Midwestern hog farm, according to a study published yesterday. The bacteria have easily shared bits of DNA that help them fight off antibiotics called carbapenems, and this is the first time such microbes have been found on a U.S. farm. When these bacteria infect humans, they are extremely difficult to treat, and are often deadly. The discovery also poses something of a mystery....

A new study maps out areas of the world that researchers think are most likely to breed the killer diseases of the future—and the highlighted countries are not the ones getting most of the resources for disease prevention. The analysis is part of a budding effort to identify emerging viruses in particular and prevent future pandemics from reaching their full potential. British and U.S. researchers compiled a database of 335 infectious diseases first acknowledged as a potential threat between 1940 and 2004....

Astronomers have discovered a pair of planets around a star 5,000 light-years away that resemble smaller versions of Jupiter and Saturn, hinting that solar systems like ours may be unexpectedly common. As in our own solar system, the closer of the two planets to their star is the larger one, 70 percent as massive as Jupiter; the more distant planet has 90 percent the mass of Saturn. The star itself, dubbed OGLE-2006-BLG-109L, is dimmer than our sun and is only half its size....

CHICAGO (Reuters) - Searchers with rescue dogs combed through a large lake resort west of Chicago on Tuesday, looking for people who might be trapped after a tornado toppled trailers and recreational vehicles, state officials said. On Monday night, a tornado tore through Woodhaven Lakes campground in Lee County, a two-hour drive from Chicago, Governor Bruce Rauner’s office said in a statement. Another tornado then hit the village of Coal City 55 miles away, injuring a handful of people and damaging some 30 homes and businesses, officials said....

African-Americans are more likely to die from cancer than patients of other races and ethnicities, and extensive studies have long implicated socioeconomic and environmental factors, such as differences in income, diet and education. Two research teams, however, have recently suggested that the genetics of race itself is likely to be a contributor. Exactly how significant the findings are and just what they mean for treatment is unclear, but some scientists worry that African-Americans could take such conclusions the wrong way, leading them not to seek treatment....

It sounds like something straight out of a video game: A snake collects toxin by biting a poisonous toad and uses that venom as a defense against hawks and other predators. But that is exactly what researchers say the Asian snake Rhabdophis tigrinus does, based on studies of glandular fluid from hatchlings and adult snakes on two Japanese islands. Some R. tigrinus snakes carry toxins called bufadienolides in their nuchal glands, sacks located under a ridge of skin along their upper necks....