Leprosy is much less common today than it was during the Middle Ages, but the bacterium that causes this debilitating disease has hardly changed since then, a new study finds.

Researchers sequenced the surprisingly well-preserved genome of the leprosy bacterium in skeletons exhumed from medieval graves in Europe. It's the first time an ancient genome has been sequenced "from scratch" (without a reference genome), and reveals that medieval leprosy strains were nearly identical to modern leprosy strains.

Leprosy, also known as Hansen's disease, is due to a chronic infection of the bacterium Mycobacterium leprae. The disease causes skin lesions that can permanently damage the skin, nerves, eyes and limbs.

While it doesn't cause body parts to fall off, those infected with leprosy can become deformed as a result of secondary infections. The disease often strikes during the peak reproductive years, but it develops very slowly, and can take 25 to 30 years for symptoms to appear.

The disease was extremely common in Europe throughout the Middle Ages, especially in southern Scandinavia. "It was a major public health problem," said study co-author Jesper Boldsen, a biological anthropologist at the University of Southern Denmark.

But leprosy declined precipitously during the 16th century. To understand why, Boldsen's colleagues sequenced DNA from five medieval skeletons, and from biopsies of living people with leprosy.

A truck-sized asteroid just discovered yesterday (Thursday, June 6) will give Earth a relatively close shave later today/early tomorrow, depending on your time zone. Asteroid 2013 LR6 is somewhere between 5- 16 meters (16 to 54 feet) in diameter and will be flying by at only about 111,000 kilometers (69,000 mi, 0.29x Lunar Distances) from Earth at 4:43UTC/12:43AM EDT on June 8, 2013.

This is similar in size to the space rock that exploded over Russia back in February of this year. The Russian asteroid was about 15 meters (50 feet) in diameter before it exploded in an airburst event about 20-25 km (12-15 miles) above Earth's surface.

Find out how you can watch the flyby live online, below.

• Animal behaviour expert Professor Con Slobodchikoff is developing technology that can translate the complex calls of prairie dogs

• He says that in 5 to 10 years, similar software could be available to have conversations with farm animals, lions and tigers and even pets

• Said that pets will be able to tell owners what they want for dinner and that being able to talk with dogs could help treat behavioural problems

We will one day be able to talk to animals using mobile phone-sized gadgets, says a leading expert in animal behaviour.

Professor Con Slobodchikoff is developing new technology that interprets the calls of the prairie dog and says the technology could eventually be used to interpret other animals.

He also suggested that the technology could one day be fine-tuned to enable humans to talk back to animals and engage in conversation.

Astronomers have discovered 26 new likely black holes in the neighboring Andromeda galaxy - the largest haul of black hole candidates ever found in a galaxy apart from our own.

Black holes, which emit almost no light themselves, can be seen only by the light given off by material falling into them. The supermassive black holes that populate the centers of most galaxies are easy to spot because their surroundings are so bright, but much smaller stellar mass black holes are considerably harder to find.

The 26 new candidates, in combination with nine previously discovered black holes in Andromeda, bring the known tally in that galaxy to 35.

"While we are excited to find so many black holes in Andromeda, we think it's just the tip of the iceberg," Robin Barnard, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., said in a statement. "Most black holes won't have close companions and will be invisible to us."

Most of the newfound black holes have about five to 10 times the mass of our sun, and resulted from the deaths of giant stars. Seven of the new candidates were found within 1,000 light-years of the center of the Andromeda galaxy - more than the number of black holes near the core of our own Milky Way.

"We are particularly excited to see so many black hole candidates this close to the center, because we expected to see them and have been searching for years," Barnard said.

Astronomers using the Swiss 1.2-metre Euler telescope at ESO's La Silla Observatory in Chile have found a new type of variable star. The discovery was based on the detection of very tiny changes in brightness of stars in a cluster. The observations revealed previously unknown properties of these stars that defy current theories and raise questions about the origin of the variations.

The Swiss are justly famed for their craftsmanship when creating extremely precise pieces of technology. Now a Swiss team from the Geneva Observatory has achieved extraordinary precision using a comparatively small 1.2-metre telescope for an observing programme stretching over many years. They have discovered a new class of variable stars by measuring minute variations in stellar brightness.

The new results are based on regular measurements of the brightness of more than three thousand stars in the open star cluster NGC 3766 [1] over a period of seven years. They reveal how 36 of the cluster's stars followed an unexpected pattern - they had tiny regular variations in their brightness at the level of 0.1% of the stars' normal brightness. These variations had periods between about two and 20 hours. The stars are somewhat hotter and brighter than the Sun, but otherwise apparently unremarkable. The new class of variable stars is yet to be given a name.

Ophthalmology textbooks describe five layers of the human cornea. They'll have to be rewritten, says University of Nottingham Professor Harminder Dua, who recently discovered a sixth layer.

"Having identified this new and distinct layer deep in the tissue of the cornea, we can now exploit its presence to make operations much safer and simpler for patients," she said in a press release.

"From a clinical perspective, there are many diseases that affect the back of the cornea which clinicians across the world are already beginning to relate to the presence, absence or tear in this layer."

The migration from desktop computing to the cloud is on every tech firm's playlist this season, with Apple [AAPL] expected to deliver improvements to its iCloud service later today -- but recent revelations regarding the US government's PRISM surveillance technology could be the kiss of death to these future tech promises.

Security is essential

Think about it: In order for cloud computing solutions to be seen as viable alternatives to more traditional desktop solutions users -- personal and business users alike -- need to be 100 percent certain their data is secure.

It is unlikely too many people want their privacy curtailed in exchange for convenience -- and reports claiming the US can pretty much tap into a user's personal data and information from any PRISM-enabled system installed in locations worldwide undermines expectation of secure data in the cloud.

The genome of mysterious bacteria that lurk in hospital drains has been sequenced.

Low levels of the bacteria, known only as candidate phylum TM6, have been found in water systems around the world, yet because they could not be cultured in the lab, almost nothing was known about them.

The new research, detailed today (June 10) in the journal Proceedings of the National Academy of Sciences, could be the first step in understanding exactly what these bacteria do, said study co-author Jeffrey McLean, a microbial geneticist at the J. Craig Venter Institute in La Jolla, Calif.

"They're this dark matter of life," McLean said. "We keep seeing them, but we don't have any other information about them. We don't know what they're doing in the environment. It could range from being beneficial to being harmful."

Washington, D.C. - Using revolutionary new techniques, a team led by Carnegie's Malcolm Guthrie has made a striking discovery about how ice behaves under pressure, changing ideas that date back almost 50 years. Their findings could alter our understanding of how the water molecule responds to conditions found deep within planets and could have implications for energy science. Their work is published in the Proceedings of the National Academy of Sciences.

When water freezes into ice, its molecules are bound together in a crystalline lattice held together by hydrogen bonds. Hydrogen bonds are highly versatile and, as a result, crystalline ice reveals a striking diversity of at least 16 different structures.

In all of these forms of ice, the simple H₂O molecule is the universal building block. However, in 1964 it was predicted that, under sufficient pressure, the hydrogen bonds could strengthen to the point where they might actually break the water molecule apart.

The possibility of directly observing a disassociated water molecule in ice has proven a fascinating lure for scientists and has driven extensive research for the last 50 years. In the mid-1990s several teams, including a Carnegie group, observed the transition using spectroscopic techniques. However, these techniques are indirect and could only reveal part of the picture.

A preferred method is to "see" the hydrogen atoms - or protons - directly. This can be done by bouncing neutrons off the ice and then carefully measuring how they are scattered.

However, applying this technique at high enough pressures to see the water molecule dissociate had simply not been possible in the past. Guthrie explained that: "you can only reach these extreme pressures if your samples of ice are really small. But, unfortunately, this makes the hydrogen atoms very hard to see."

Discovery: Date May 9, 2013

Magnitude: 19.3 mag

Discoverer: R. A. Kowalski (Catalina Sky Survey)

The orbital elements are published on M.P.E.C. 2013-K31.