As a comet approaches the Sun, it heats up and begins to outgas, causing jets of gas and dust to erupt from its surface. These jets can sometimes act like tiny rocket engines, spinning up the comet's rotation and loosening chunks of material that drift off into space.

Over the span of three days in January 2016, the Hubble Space Telescope captured detailed images of just that scenario happening to Comet 332P/Ikeya-Murakami, or Comet 332P, located roughly 67 million miles from Earth.

The Hubble observations revealed 25 building-size blocks made of a mixture of ice and dust that broke off from the comet and are now are scattered along a 3,000-mile-long trail, larger than the width of the continental U.S. The icy chunks comprise about 4 percent of the parent comet and range in size from roughly 65 feet wide to 200 feet wide. They are drifting away from the comet and each other at a few miles per hour, about the walking speed of an adult. See animation here.

The Hubble observations also reveal that the comet is much smaller than previously thought, measuring only 1,600 feet across, about the length of five football fields.

According to a NASA statement, these observations provide insight into the volatile behavior of comets as they approach the sun, begin to vaporize, and unleash dynamical forces. Comet 332P was 150 million miles from the sun, slightly beyond the orbit of Mars, when Hubble spotted the breakup.

A jealous Planet Nine may have shoved its siblings for attention. If a massive ninth planet exists in our solar system, it might explain why the planets are out of line with the sun.

The eight major planets still circle the sun in the original plane of their birth. The sun rotates on its own axis, but surprisingly, that spin is tilted: the axis lies at an angle of 6 degrees relative to a line perpendicular to the plane of the planets.

There are a few theories to explain this jaunty slant, including the temporary tug of a passing star aeons ago, or interactions between the magnetic fields of the sun and the primordial dusty disc that formed the solar system. But it is hard to account for why the sun's spin is aligned the way it is relative to the planets.

Two teams of astronomers have just announced a new explanation: a hypothetical massive planet in the outer solar system could be interfering with all the other planets' orbits.

The genome of a mysterious ancient fossil has shaken up the elephant family tree.

Modern elephants are classified into three species: the Asian elephant (Elephas maximus) and two African elephants — the forest-dwellers (Loxodonta cyclotis) and those that live in the savannah (Loxodonta africana). The division of the African elephants, originally considered a single species, was confirmed only in 2010.

Scientists had assumed from fossil evidence that an ancient predecessor called the straight-tusked elephant (Paleoloxodon antiquus), which lived in European forests until around 100,000 years ago, was a close relative of Asian elephants.

In fact, this ancient species is most closely related to African forest elephants, a genetic analysis now reveals. Even more surprising, living forest elephants in the Congo Basin are closer kin to the extinct species than they are to today's African savannah-dwellers. And, together with newly announced genomes from ancient mammoths, the analysis also reveals that many different elephant and mammoth species interbred in the past.

"It's mind blowing," says Tom Gilbert, an evolutionary geneticist at the Natural History Museum of Denmark in Copenhagen. The straight-tusked elephant is little-known even among experts, he says. "And the first thing we hear about it is: here's the genome."

Patrick Paumen doesn't have to worry about forgetting his keys and being locked out of his apartment. That is because he doesn't need a key anymore—he simply unlocks the door with a wave of his hand. The 32-year-old IT expert from the Dutch city of Heerlen is one of a growing number of people with electronic implants under their skin, mostly to use as keys or for identification.

Mr. Paumen has several such implants, or tags, embedded in the fatty tissue of his hands and his lower arm. He uses separate tags to unlock not only his apartment door, but also his office and the gate to a secure parking lot at work. Another stores information he would otherwise put on a business card—name and contact details—and yet another holds similar information for nonbusiness encounters.

The implants can be activated and scanned by readers that use radio frequency identification technology, or RFID. Those include ordinary smartphones and readers already installed in office buildings to allow entrance with a common ID card.

Mr. Paumen says the tiny devices simplify his life. When nearing the secure office parking lot, he says, "I just roll down the window, stick my arm out and let the reader at the gates scan the implant, which is just below my little finger. I don't have to worry about losing my access card."

Done in seconds

There is no comprehensive data on how many people have RFID implants in their bodies, but retailers estimate the total is 30,000 to 50,000 people globally. The fact that the tags can't be lost is one attraction. Another, users say, is that the tags don't operate under their own power but rather are activated when they're read by a scanner. That means they can never be rendered useless by a dead battery like smartphones.

Dolphins are super-smart and they have a language. New research has probed the complexity of this language and concludes that dolphins not only communicate words with each other, but they are also capable of constructing sentences.

The research comes via the Russian Academy of Scientists from a study of Black Sea bottlenose dolphins (Tursiops truncatus.) Here a pair of dolphins were observed communicating with each other in a manner that was sophisticated, had a form of structure and is seen as akin to a sentence. Exactly what the dolphins were communicating to each other is uncertain.

Bottlenose dolphins are a common type of dolphin, living groups (or 'pods') typically of 10 - 30 members. These dolphins have a has a grey color, with the shade of grey varying among populations. Dolphins are remarkable in that they search for prey primarily using echolocation (a type of sonar).

Consciousness isn't something scientists like to talk about much. You can't see it, you can't touch it, and despite the best efforts of certain researchers, you can't quantify it. And in science, if you can't measure something, you're going to have a tough time explaining it.

But consciousness exists, and it's one of the most fundamental aspects of what makes us human. And just like dark matter and dark energy have been used to fill some otherwise gaping holes in the standard model of physics, researchers have also proposed that it's possible to consider consciousness as a new state of matter.

To be clear, this is just a hypothesis, and one to be taken with a huge grain of salt, because we're squarely in the realm of the hypothetical here, and there's plenty of room for holes to be poked.

But it's part of a quietly bubbling movement within theoretical physics and neuroscience to try and attach certain basic principles to consciousness in order to make it more observable.

A live test-fire of a rapid-firing autocannon designed for the T-50 fifth-generation fighter jet has been filmed by Russia's United Aircraft Corporation (UAC). The short but stunning footage conveys the power of the new weapon.

The test took place at a testing ground for aircraft systems located outside Moscow.

The one-minute footage, uploaded to UAC's website and the official YouTube channel, shows the gun - reportedly called 9-А1-4071K - mounted on a fixed stand simulating the front part of the T-50.

Critical information regarding Russia's newest and most advanced fifth-generation fighter jet remains classified, but it has been revealed that the autocannon is fitted to fire 30mm rounds.

Long ago, one great ocean flowed between North and South America. When the narrow Isthmus of Panama joined the continents about 3 million years ago, it also separated the Atlantic from the Pacific Ocean. If this took place millions of years earlier, as recently asserted by some, the implications for both land and sea life would be revolutionary. Aaron O'Dea, staff scientist at the Smithsonian Tropical Research Institute (STRI), and colleagues writing in Science Advances firmly set the date at 2.8 million years ago.

"Recent scientific publications proposing the isolation of the two oceans between 23 to 6 million years ago rocked the generally held model of the continental connection to its foundations," said Jeremy Jackson, emeritus staff scientist at the Smithsonian. "O'Dea and his team set out to reevaluate in unprecedented, rigorous detail, all of the available lines of evidence -- geologic, oceanographic, genetic and ecological data and the analyses that bear on the question of when the Isthmus formed."

"The timing of the connection between continents and the isolation of the Pacific and Atlantic oceans is important for so many reasons," O'Dea said. "Estimates of rates of evolutionary change, models of global oceans, the origin of modern-day animals and plants of the Americas and why Caribbean reefs became established all depend upon knowing how and when the isthmus formed."

The turquoise waters became darker and darker, and squiggly glow-in-dark marine creatures began to glide past in the inky depths like ghosts.

The three-man submarine went down, down, down into the abyss and drew within sight of something no human had ever laid eyes on: Cook seamount, a 13,000-foot extinct volcano at the bottom of the sea.

Scientists aboard the vessel Pisces V visited the volcano earlier this month to examine its geological features and its rich variety of marine life, and an Associated Press reporter was given exclusive access to the dive. It was the first-ever expedition to the Cook seamount by a manned submersible.

Given the choice, many dogs prefer praise from their owners over food, suggests a new study published in the journal Social, Cognitive and Affective Neuroscience. The study is one of the first to combine brain-imaging data with behavioral experiments to explore canine reward preferences.

"We are trying to understand the basis of the dog-human bond and whether it's mainly about food, or about the relationship itself," says Gregory Berns, a neuroscientist at Emory University and lead author of the research. "Out of the 13 dogs that completed the study, we found that most of them either preferred praise from their owners over food, or they appeared to like both equally. Only two of the dogs were real chowhounds, showing a strong preference for the food."