Rare, dying, giant radio galaxy 9 billion light years away

This is an optical image with radio lobes (in yellow-red). The supermassive black hole in the red galaxy at the centre (zoomed in inset) has led to the formation of the giant radio lobes.

A team of astronomers working at the National Centre for Radio Astrophysics (NCRA, TIFR), Pune have discovered, using the Giant Metrewave Radio Telescope (GMRT), an extremely rare galaxy of gigantic size. This galaxy -- located about 9 billion light years away towards the constellation Cetus -- emits powerful radio waves and has an end to end extent of a whopping 4 million light years! Such galaxies with extremely large 'radio size' are appropriately called giant radio galaxies.

How do galaxies with an optical size of a hundred thousand light years produce radio emission several million light years in extent? It is argued that the presence of a super massive black hole at the centre of the galaxy drives large scale jets of hot plasma in diametrically opposite directions which eventually give rise to large radio lobes (see the image). While radio galaxies with size less than a million light years are common, giant radio galaxies are extremely rare, even more so, at large cosmic distances where only a handful have been discovered so far. This newly discovered galaxy known by its scientific name 'J021659-044920' is the newest member of this elite group.

Under some special circumstances, the central black hole may stop producing the radio jet, and then the bright radio lobes fade away, within a few million years, due to lack of replenishment. What makes J021659-044920 special, is that it has been caught in this dying phase, where the radio jet appears to have switched off and the radio lobes have started fading. The fading of the lobes is caused by their losing energy in two ways, one, by emitting radio waves which show up as the gigantic radio lobes and two, by transferring energy to photons from the cosmic microwave background via a process known as inverse Compton scattering. This latter mechanism leads to faint X-ray emission, which is seen to emanate from the radio lobes of this galaxy. Such dying radio objects are best studied using a low frequency radio telescope such as the GMRT. The GMRT, the world's largest radio telescope facility operating at low radio frequencies, is an array of 30 fully steerable, 45 metre diameter antennas, spread out over a 30 km region around Khodad, near Narayangaon town of Pune district in western India. The GMRT was built and is operated by National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research and has been in operation since 2002.

For their analysis, the team combined their GMRT observations with previous observations made with a slew of international ground and space based telescope facilities -- XMM-Newton Space Telescope in X-ray, the Japanese Subaru telescope in optical, UK's Infrared Telescope in near-infrared, NASA's Spitzer Space Telescope in mid-infrared and the Jansky Very Large Array (USA) in high frequency radio bands. By using data from multiple telescopes spanning across the electromagnetic spectrum, they were able to carry out a comprehensive and incredibly detailed analysis of the physical conditions around this distant galaxy. The properties of the magnetic field in the region between galaxies in the distant universe can be understood with these observations.

From Science Daily

Hubble uncovers the fading cinders of some of our galaxy's earliest homesteaders

Using NASA's Hubble Space Telescope to conduct a "cosmic archaeological dig" at the very heart of our Milky Way galaxy, astronomers have uncovered the blueprints of our galaxy's early construction phase.

Peering deep into the Milky Way's crowded central hub of stars, Hubble researchers have uncovered for the first time a population of ancient white dwarfs -- smoldering remnants of once-vibrant stars that inhabited the core. Finding these relics at last can yield clues to how our galaxy was built, long before Earth and our sun formed.

The observations are the deepest, most detailed study of the galaxy's foundational city structure -- its vast central bulge that lies in the middle of a pancake-shaped disk of stars, where our solar system dwells.

As with any archaeological relic, the white dwarfs contain the history of a bygone era. They contain information about the stars that existed about 12 billion years ago that burned out to form the white dwarfs. As these dying embers of once-radiant stars cool, they serve as multi-billion-year-old time pieces that tell astronomers about the Milky Way's groundbreaking years.

An analysis of the Hubble data supports the idea that the Milky Way's bulge formed first and that its stellar inhabitants were born very quickly -- in less than roughly 2 billion years. The rest of the galaxy's sprawling disk of second- and third-generation stars grew more slowly in the suburbs, encircling the central bulge like the brim of a giant sombrero.

"It is important to observe the Milky Way's bulge because it is the only bulge we can study in detail," explained Annalisa Calamida of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, the science paper's lead author. "You can see bulges in distant galaxies, but you cannot resolve the very faint stars, such as the white dwarfs. The Milky Way's bulge includes almost a quarter of the galaxy's stellar mass. Characterizing the properties of the bulge stars can then provide important information to understanding the formation of the entire Milky Way galaxy and that of similar, more distant galaxies."

The Hubble survey also found slightly more low-mass stars in the bulge, compared to those in the galaxy's disk population. "This result suggests that the environment in the bulge may have been different than the one in the disk, resulting in a different star-formation mechanism," Calamida said.

The observations were so sensitive that the astronomers also used the data to pick out the feeble glow of white dwarfs. The team based its results on an analysis of 70 of the hottest white dwarfs detectable by Hubble in a small region of the bulge among tens of thousands of stars.

These stellar relics are small and extremely dense. They are about the size of Earth but 200,000 times denser. A teaspoon of white dwarf material would weigh about 15 tons. Their tiny stature makes them so dim that it would be as challenging as looking for the glow of a pocket flashlight located on the moon. Astronomers used the sharp Hubble images to separate the bulge stars from the myriad stars in the foreground of our galaxy's disk by tracking their movements over time. The team accomplished this task by analyzing Hubble images of the same field of 240,000 stars, taken 10 years apart. The long timespan allowed the astronomers to make very precise measurements of the stars' motion and pick out 70,000 bulge stars. The bulge's stellar inhabitants move at a different rate than stars in the disk, allowing the astronomers to identify them.

The region surveyed is part of the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS) field and is located 26,000 light-years away. The unusually dust-free location on the sky offers a keyhole view into the "downtown" bulge. Hubble's Advanced Camera for Surveys made the observations in 2004 and 2011-2013.

"Comparing the positions of the stars from now and 10 years ago we were able to measure accurate motions of the stars," said Kailash Sahu of STScI, the study's leader. "The motions allowed us to tell if they were disk stars, bulge stars, or halo stars."

The astronomers identified the white dwarfs by analyzing the colors of the bulge stars and comparing them with theoretical models. The extremely hot white dwarfs appear bluer relative to sun-like stars. As white dwarfs age, they become cooler and fainter, becoming difficult even for sharp-eyed Hubble to detect.


Read more at Science Daily

Birchbark Message Tells Story of Medieval Traveler

A sad tale of a Medieval traveler has emerged from the historical center of Moscow as archaeologists unearthed a rare letter written on birch bark.

Dated to the 14th century, the manuscript was found in a district close to Red Square by a team of the Russian Academy of Sciences who dug 13 feet down. They retrieved hundreds of objects that provide new information about life in Moscow in the Middle Ages.

The letter, by an unknown author, is addressed to “Sir” and recounts the troubled trip of an unnamed individual.

Birch bark as writing surface was popular in Medieval Russia. The first birch bark manuscripts were found during archaeological excavations in Velikiy Novgorod in the 1950s.

Since then, more than 1,000 manuscripts have been discovered in Novgorod, dating from the 11th to the 14th centuries. The find suggests the humble Medieval inhabitants there had an unusually high level of literacy.

Letters were produced by scratching the inner surface of a strip of birch bark; texts included everything from “I owe you” notes and birthday greetings to contracts, letters and children’s drawings.

While birch bark manuscripts were found in large numbers in Novgorod, only three letters have been discovered in Moscow until now and only one contains a detailed text, which was mainly an inventory.

The newly found letter, the fourth found in Moscow, was written by an unknown author and was addressed to “Sir.”

The manuscript recounts the misfortunes of an unnamed individual. Headed to Kostroma, a city about 217 miles north east of Moscow, the individual and other people were detained by someone, “who had the right to do so,” possibly an official.

The authority took from the unlucky traveler a lot of money. We do not know what happened afterwards, but it seems unlikely the penniless travelers reached their destination.

Read more at Discovery News

New Clues Point to Secret Chamber in King Tut Tomb

The investigation of King Tut’s tomb to find secret chambers ended today with promising results, according to a statement from Egypt’s antiquity ministry.

A team from Cairo University’s Faculty of Engineering and the Paris-based organization Heritage, Innovation and Preservation used infrared thermography to detect the temperature of the walls in the tomb. Preliminary analysis indicates the presence of an area different in its temperature than the other parts of the northern wall.

“The experiment lasted for 24 hours,”  Egypt’s Antiquities minister Mamdouh Eldamaty said in a statement.

In order to certify the results, Eldamaty said, a number of experiments will be carried out to determine more accurately the area showing the difference in temperature.

“The team was very impressed and full of emotion to spend the night in the tomb,”  Mehdi Tayoubi, founder of the Paris-based Heritage Innovation Preservation Institute, told Discovery News.

The non-invasive search follows a claim by Nicholas Reeves, a British Egyptologist at the University of Arizona, that high-resolution images of the tomb’s walls show “distinct linear traces” pointing to the presence of two still unexplored chambers behind the western and northern walls of the tomb.

According to Reeves, one chamber contains the remains, and possibly the intact grave goods, of queen Nefertiti, the wife of the “heretic” monotheistic pharaoh Akhenaten, Tutankhamun’s father.

He argued that a painting located behind King Tut’s sarcophagus has been wrongly interpreted. Egyptologists have always believed the scene shows Ay (who largely directed King Tut’s reign and succeeded him) performing the Opening of the Mouth ritual on the boy king.

Reeves believes the figure labelled Tutankhamun is actually Nefertiti. He noted that a line at the side of the figure’s mouth, called “oromental groove,” is a trademark in pictures of Nefertiti. On the other hand, the figure labelled Ay would be Tutankhamun, completing the death ritual for Nefertiti.

Reeves speculated that the tomb of King Tut was not ready when he died unexpectedly at 19 in 1323 B.C. after having ruled a short reign of nine to 10 years. Consequently, he was buried in a rush in what was originally Nefertiti’s tomb, who had died 10 years earlier.

Reeves’s claim  about Nefertiti has stirred  a debate among Egyptologists and mummy experts.

An international team of researchers led by mummy expert Frank Rühli, director of the Institute of Evolutionary Medicine at the University of Zurich,  cautioned last month about the possibility of Nefertiti being the occupant of the secret crypt.

They argued Nefertiti  might be the already found Younger Lady, a mummy found in 1898 by archaeologist Victor Loret in tomb KV35 in the Valley of the Kings.

Nefertiti is labelled in inscriptions to be Tutankhamun’s mother; genetic analyses identified the “Younger Lady” as the mother of Tutankhamun.

Such evidence would automatically rule out Nefertiti, the researchers concluded.

If a mummy is found, it could belong to the elusive pharaoh Smenkhkare, or to queen Meritaton, the full or half sister of Tutankhamun, they added.

It is also possible that nothing at all will be found behind those walls, they said.

Investigations in King Tut’s tomb are expected to continue.

Read more at Discovery News

Alien Megastructure? SETI Spies No Intelligent Signals

After all the public excitement surrounding the star KIC 8462852 and its weird transit signal as spotted by NASA’s Kepler Space Telescope, the SETI Institute decided to expedite plans to point a powerful radio antennae at the nearby star in the hope of detecting any artificial transmissions emanating from that location. Sadly (or not, depending on how you view the discovery of an intelligent alien civilization living in our cosmic backyard), the first pass drew a blank.

So, is this “case closed” for the possibility of an alien megastructure around KIC 8462852? Well, not really, but it does make a vanishingly slim chance of aliens even more vanishingly slim.

But before we discuss what SETI has (or, indeed hasn’t) found, a quick recap.

Aliens! Or Not

In September, astronomers and citizen scientists published a paper describing a “bizarre” transit signal recorded by Kepler, outlining a few possible causes for the phenomenon around KIC 8462852 — also informally known as “Tabby’s Star.” On 2 occasions during Kepler’s prime observing run, huge transits were detected around the star.

Usually, Kepler will detect periodic dips in star brightness and the amount of dimming relates to the size of the exoplanet passing in front of the star. Typically, for a small exoplanet, this dip in brightness is of the order of a couple of percent. But the two transit signals detected around Tabby’s Star were dramatic. The first transit dipped by 15 percent, but the second transit (that consisted of several objects passing in front of the star over several weeks) dipped to as much as 22 percent. The strength of the transit and its multi-object nature was unprecedented.

Many natural phenomena were explored and the researchers eventually focused on the possibility of a swarm of comets as being the most likely culprit. A nearby star, they argued, may have destabilized comets in Tabby’s Star’s Oort cloud (a hypothetical region surrounding a star containing countless billions of icy bodies), nudging a huge number of comets toward the star, blocking its light from view.

This explanation certainly fits many of the transit’s characteristics, but during an interview with The Atlantic, astronomer Jason Wright, an astronomer from Penn State University, discussed an alternate avenue of study that he wanted to investigate. On many occasions since, Wright and other astronomers have cautioned against jumping to the alien conclusion — after all, there are other, more likely natural explanations — but when faced with an unprecedented transit signal, why not explore the most extreme possibilities?

As with any speculation about aliens, the slim possibility of this Kepler signal being artificial caused an eruption of interest. While many scientists vented frustration at the frenzy of interest surrounding an unlikely scenario, whether they liked it or not, suddenly everyone was interested in Kepler science and hypotheses of an advanced alien civilization living in our galaxy. In my personal view, so long as the discussion remained planted firmly in the science, and not conspiracy theories and nonsense, this was no bad thing — especially as professional scientists were planning on investigating the possibility themselves.

Allen Telescope Array

So, if not comets, what could be causing the bizarre transit signal? Taking the age of our galaxy into consideration, it’s not such a stretch to think that if life is common in the Milky Way, perhaps there’s a vastly more advanced civilization to our own out there that has the ability to build huge solar energy collectors, say, around their host star. This speculation would certainly fit a Type II Kardashev civilization that has the ability to build huge megastructures around a star (much like a Dyson Sphere) to collect huge quantities of energy. Perhaps Kepler’s transit signal was several vast solar collectors passing in front of the star?

While it’s fun to think up all the possible structures an intelligent alien race might build, seeing a star dim a couple of times is hardly proof that aliens are out there. It’s not even evidence, especially when Occam’s Razor reminds us that there are other explanations out there with far fewer assumptions (i.e. the exocomet explanation). But in the interest of using Tabby’s Star as a point of scientific interest and respond to the huge public interest in the star, SETI Institute scientists turned to the their Allen Telescope Array (ATA) to “listen in” on the location.

The ATA is located a few hundred miles north of San Francisco, Calif., in the Cascade Mountains, consisting of 42 6-meter diameter radio antennae. The ATA was aimed at Tabby’s Star for 2 weeks and listened out for 2 specific radio signals. The first signal, of a narrow-band 1 Hz bandwidth, might be used as a “hailing signal”, according to the SETI Institute, for advanced alien civilizations to announce their presence. The second signal may be of a more broad-band emission that could signify an alien presence through the leakage of beamed propulsion in the star system. Beamed propulsion is one hypothetical method that could be used to power spacecraft in the future, so if there’s an alien megastructure around that star, there would likely be spacecraft too, possibly sporting this propulsion method.

“This is the first time we’ve used the Allen Telescope Array to look for relatively wide-band signals, a type of emission that is generally not considered in SETI searches,” said SETI Institute scientist Gerry Harp in a news release.

But on this first 2 week pass, the ATA didn’t detect either type of signal emanating from Tabby’s Star:

Analysis of the Array data show no clear evidence for either type of signal between the frequencies of 1 and 10 GHz. This rules out omnidirectional transmitters of approximately 100 times today’s total terrestrial energy usage in the case of the narrow-band signals, and ten million times that usage for broad band emissions. — SETI Institute

Slim Possibilities

This finding provides an upper limit on our ability to detect these most powerful signals — if these hypothetical aliens possess the energy required to build vast structures around stars, they will certainly have the energy required to generate such powerful beacons. But say if they’re not deliberately transmitting? Well, that might explain why we’re not hearing the narrowband “hailing” signal. Say if there’s little activity around these structures? That might explain why there’s little radio “leakage” from the star. What if these are structures left in orbit by a bygone alien civilization? Perhaps they’re monuments of an empire that is long gone. A fascinating thought.

Once again, we’re speculating about what these hypothetical aliens are or are not, but the SETI investigation certainly rules out certain scenarios.

Read more at Discovery News

Complex skeletons evolved earlier than realized, fossils suggest

The first animals to have complex skeletons existed about 550 million years ago, fossils of a tiny marine creature unearthed in Namibia suggest.

The find is the first to suggest the earliest complex animals on Earth -- which may be related to many of today's animal species -- lived millions of years earlier than was previously known.

Until now, the oldest evidence of complex animals -- which succeeded more primitive creatures that often resembled sponges or coral -- came from the Cambrian Period, which began around 541 million years ago. Scientists had long suspected that complex animals had existed before then but, until now, they had no proof.

Genetic family tree data suggested that complex animals -- known as bilaterians -- evolved prior to the Cambrian Period. The finding suggests that bilaterians may have lived as early as 550 million years ago, during the late Ediacaran Period.

The study suggests that complex animals existed long before a period in the planet's history -- known as the Cambrian explosion -- during which most major animal groups evolved.

The team studied fossils of an extinct marine animal -- known as Namacalathus hermanastes -- which was widespread during the Ediacaran Period. The fossils are remarkably well preserved and reveal that the species possessed a rigid skeleton made of calcium carbonate -- a hard material from which the shells of marine animals are made. The complex skeletal structures are similar to those of living creatures that dwell at the bottom of the sea, the team says.

The study, published in the journal Proceedings of the Royal Society B, was funded by the Natural Environment Research Council. The research was carried out in collaboration with Lomonosov Moscow State University.

Read more at Science Daily

The Mystery of the Arctic’s Toxic, Lethargic Shark

Don't let the motion blur fool you—the Greenland shark is a comically slow swimmer. That blur is probably just the photographer's creative touch. Nice work, Doug.

In Iceland they have this delicacy called hákarl that recently initiated diners describe as “the worst tasting food on Earth,” “the world’s foulest food,” and “the worst thing I have ever had in my mouth.” To say it smells like a urinal would be generous. Not that anyone should be surprised, considering hákarl is rotten shark meat fermented in the dirt or open air for months on end.

Hákarl is no ordinary delicacy, but then again, it comes from no ordinary fish: The Greenland shark has toxic flesh (hence the detoxification via fermentation). It’s also one of the most mysterious, weirdest, and largest sharks on Earth. It dives thousands of feet deep in arctic waters and grows to over 20 feet long. It’s also comically slow, averaging less than a single mile per hour—yet, bafflingly, it seems to be an apex predator.

For the Greenland shark, pretty much everything is on the menu. Surveys of their stomach contents have revealed squid, fish, and whale meat. In 2013, two dudes in Canada found a beached Greenland shark that may have been choking on a piece of, um, moose.

The Greenland shark is a scavenger, and it certainly has the teeth for it. “The upper jaw has sharply pointed teeth, almost like needles, and those are really well adapted for sinking into flesh and holding onto it,” says marine biologist Gregory Skomal of Massachusetts Marine Fisheries. “The lower jaw has teeth arranged in rows that look very similar to what one would see on a saw used to cut wood, and so they’re really nice cutting tools.” The Greenland shark is probably getting a grip on a carcass with its upper teeth, then twisting to gouge out a chunk of flesh with the lower teeth.

But that mouth could also do the shark well for hunting live prey. Consider the cookiecutter shark, which has similar dentition. This small, zippy species gouges flesh like the Greenland, only it targets living fish and whales and at least one unfortunate man on a swim between Hawaiian islands—at night (I mean, I’m not his father, but come on). The Greenland may be doing the same to marine mammals in the arctic. Scientists have photographed beluga whales, for instance, with big plugs of flesh taken out of them.

Then we have the curious happenings on Sable Island off the coast of Nova Scotia. Seals here have shown up with corkscrew-shaped wounds spiraling down their flesh, at times with half their bodies stripped of skin and blubber, like peeled potatoes. Some scientists say it could be the work of Greenland sharks, others blame boat propellers. No one has ever caught a shark in the act, so the culprit remains a mystery.

“I have personally been in the water with Greenland sharks and handled them like they were inanimate objects,” Skomal says. “They’re incredibly docile and don’t appear to have any capacity to accelerate and capture a seal.” But consider the fact that seals can sleep in the water, bobbing with just their heads above the surface (known as “bottling,” because why not), to avoid polar bears. That’d make them vulnerable to Greenland sharks.

Lazy, But at Least in a Productive Way

If you ask biologist Peter Bushnell of Indiana University, South Bend, the seals may not even need to be sleeping for the Greenland shark to snag them. Given the presence of so much fish in the shark’s stomach contents—and often a total lack of mud, which you’d expect to find in something that’s just scavenging on the seafloor—he has no doubts it’s an active predator.

When a sheet of ice covers the sea, seals pop in and out of holes to hunt fish—a behavior the Greenland sharks may be exploiting. “I have a feeling they can slowly meander their way up to an ice hole and just park themselves for a couple of days,” Bushnell speculates. “And a naive seal plops itself in and there it is.” Thus could a lethargic predator manage to take down a spry victim like a seal while barely exerting itself.

Live fish, too, may be food for the Greenland shark, Bushnell reckons. The shark’s jaws are somewhat extensible, and like a lot of fish (oh, and a certain 6-foot-long salamander), the Greenland may be able to rapidly open its maw to create a suction effect. Imagine the shark sneaking up on a school of cod in the deep dark sea: “With a little bit of a lunge forward and a suck, you’ve got dinner,” Bushnell says.

What makes this even more incredible? A good number of Greenland sharks can’t see worth a damn, thanks to a parasitic crustacean that bores into their eyeballs and feeds on their corneas because there is no justice in the world. It’s all the rage, really: One study found that 100 percent of Greenland sharks caught near Svalbard, Norway had parasites attached to their peepers.

The parasite can severely damage the eye, either impairing the shark’s vision or snatching it away altogether. But by virtue of being a shark, the Greenland can fall back on its fantastic sense of smell—and indeed it has a massive olfactory bulb in its brain.

Yep, that’s a parasitic crustacean that’s latched on to a Greenland shark’s eyeball. Remember that time you complained about having to put contacts in every day?

Yet if Greenland sharks are indeed going after slumbering seals, or ones that drop into the water right in front of their faces, maybe vision isn’t all that important. On the flipside, though, the Greenland’s “big nose is really effective at finding scent trails from dead animals,” says Skomal, “and therefore supports the notion that it’s evolved to be a deep-water scavenger.”

Clearly, the ecology of the Greenland shark is still somewhat of a riddle. The active predation part is a particular head-scratcher. “It is a bit of a conundrum, but the one thing that is clear is they are active predators,” Bushnell says. “How they do this, I’m not sure.”

What is also clear is that the Greenland shark is well-adapted for the deep, and this may be where its toxicity comes into play.
Greenland Shark Meat: It’s Like Kibbles ‘n Bits, Except It Gives Dogs Explosive Diarrhea

Back in the ‘60s, soon-to-be-regretful humans fed Greenland shark meat to a pack of sled dogs, which suffered convulsions, respiratory distress, and explosive diarrhea. The problem may have been high levels of the compound trimethylamine N-oxide (TMAO) in Greenland shark flesh. This could help the animal maintain osmotic balance—that is, balancing its internal salt chemistry with the salt chemistry of the water. But why would levels of TMAO be so much higher in a Greenland’s flesh than in other sharks?

It may, Skomal reckons, come down to the uniqueness of the arctic environment, and especially the deep-sea arctic environment: lots of salt. “You tend to have higher salinity areas in northern latitudes,” he says, “because you get this very thick seasonal ice layer and sometimes permanent ice layer that extracts fresh water from the ocean.”

Read more at Wired Science

Common Tapeworm in Humans Spreads Tumors

Stunned scientists described on Wednesday the first known case of a man infected with tumors by a common parasitic tapeworm, raising concern about more such infections that may go undetected.

"We were amazed when we found this new type of disease -– tapeworms growing inside a person essentially getting cancer that spreads to the person, causing tumors," said Atis Muehlenbachs, staff pathologist in the US Centers for Disease Control and Prevention's Infectious Diseases Pathology Branch.

"We think this type of event is rare. However, this tapeworm is found worldwide and millions of people globally suffer from conditions like HIV that weaken their immune system. So there may be more cases that are unrecognized," added Muehlenbachs, lead author of the study in the New England Journal of Medicine.

The case involved a 41-year-old man in Colombia. He was HIV-positive and not been taking medications when in 2013, he went to his doctors with a cough, fever and complaints of weakness and weight loss.

His doctors took biopsies from his lymph nodes and lung tumors, and appealed to the CDC for help in diagnosing some bizarre-looking lesions which looked like human cancer, but initial lab tests showed they were not human.

Puzzled, scientists kept searching for the cause of the man's disease.

"The growth pattern was decidedly cancer like, with too many cells crowded into small spaces and quickly multiplying," the CDC said in a statement.

"But the cells were tiny -- about 10 times smaller than a normal human cancer cell. The researchers also noticed cells fusing together, which is rare for human cells."

After dozens of tests, they found DNA from Hymenolepis nana, the dwarf tapeworm, in the man's tumor in mid-2013.

The man died soon after.

The dwarf tapeworm is the most common tapeworm in humans, and infects up to 75 million people at any given time.

People can get it by eating food that has mouse feces on it, or ingesting feces from an infected person.

It often affects children, and many people show no symptoms.

"However, in people whose immune systems are weak, including people who have HIV or are taking steroids, the tapeworm thrives," the CDC said.

H. nana is the only one of some 3,000 known tapeworms that can complete its entire life cycle from egg to adult tapeworm in an individual's small intestine.

Rarely are infections of the tapeworm found outside the small intestine, but in the case of the Colombian man, his weakened immune state may have enabled the parasite's cancer to spread through his body.

Read more at Discovery News

Meet the Mexican Walking Fish, an Animal on the Brink

Although it may look like a whimsical cartoon character, the axolotl (Ambystoma mexicanum) is in serious trouble.

Also known as the Mexican Walking Fish, this critically endangered salamander is naturally found only in the local waterways near Mexico City. Rapid urbanization and subsequent water pollution have destroyed much of the creature's habitat, and the introduction of non-native species into the salamander's habitat had a detrimental impact on dwindling population.

During a 2013 survey, researchers were unable to find any wild axolotls, fomenting fears that the animal may be completely extinct in the wild. Luckily, a handful of the elusive creatures have since been spotted.

The axolotl is also alive and well in laboratories around the world, and is a staple of the exotic pet trade.

Although it can live beyond 20 years, the creature's average lifespan is closer to a decade. The salamander typically grows to be just under a foot in length.

Fun fact: the axolotl is known to swallow small gravel and small pebbles, which help the creature maintain its buoyancy in the water. In the absence of small pebbles, the creature may attempt to swallow other small objects in the water -- like plastic pollution -- which can be extremely harmful to its health.

From Discovery News

19th Century Burial Found Under NYC Park

Workers upgrading water mains under New York City’s Washington Square Park this week discovered a vault containing a large pile of skeletal remains dating back approximately 200 years.

Officials from the city’s Department of Design and Construction told Newsday that the vault measured 8 feet deep, 15 feet wide and 20 feet long. It contained the remains of at least a dozen people. Anthropologists and archaeologists would be asked to investigate the vault to determine its exact age.

The agency told DNAInfo that work on the project would continue as planned south of the burial site. The vault was discovered east of the park, in an area surrounded by New York University buildings.

The land where the park is now located was a so-called potter’s field, or public burial ground, between 1797 and 1825. The city bought the land the following year and turned it into a military parade ground, and then a park.

Historians have estimated that approximately 20,000 people were buried underneath the park.

From Discovery News