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.

Every summer, something strange and wonderful happens high above the north pole. Ice crystals begin to cling to the smoky remains of meteors, forming electric-blue clouds with tendrils that ripple hypnotically against the sunset sky. Noctilucent clouds - a.k.a. "NLCs"--are a delight for high-latitude sky watchers, and around the Arctic Circle their season of visibility is always eagerly anticipated.

News flash: This year, NLCs are getting an early start. NASA's AIM spacecraft, which is orbiting Earth on a mission to study noctilucent clouds, started seeing them on May 13th.

"The 2013 season is remarkable because it started in the northern hemisphere a week earlier than any other season that AIM has observed," reports Cora Randall of the Laboratory for Atmospheric and Space Physics at the University of Colorado. "This is quite possibly earlier than ever before."

Scientists using images from NASA's Mars Reconnaissance Orbiter (MRO) have estimated that the planet is bombarded by more than 200 small asteroids or bits of comets per year forming craters at least 12.8 feet (3.9 meters) across. Researchers have identified 248 new impact sites on parts of the Martian surface in the past decade, using images from the spacecraft to determine when the craters appeared. The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet.

MRO's High Resolution Imaging Science Experiment (HiRISE) camera took pictures of the fresh craters at sites where before-and-after images by other cameras bracketed when the impacts occurred. This combination provided a new way to make direct measurements of the impact rate on Mars. This will lead to better age estimates of recent features on Mars, some of which may have been the result of climate change.
"It's exciting to find these new craters right after they form," said Ingrid Daubar of the University of Arizona, Tucson, lead author of the paper published online this month by the journal Icarus. "It reminds you Mars is an active planet, and we can study processes that are happening today."

These asteroids or comet fragments typically are no more than 3 to 6 feet (1 to 2 meters) in diameter. Space rocks too small to reach the ground on Earth cause craters on Mars because the Red Planet has a much thinner atmosphere.

The developers of a new mobile app may have just caught a break - and found a new group of potential customers - with the revelation that government is secretly snooping on Verizon cell phone users.

Developers in South Africa have developed an app called Seecrypt, which they say protects cell phone users from having their calls and texts tracked.

It was revealed Wednesday that the National Security Agency has forced Verizon to turn over phone records of customers inside the United States in the name of fighting terrorism.

But the developers of Seecrypt say you can get around the NSA with their app.

Users, according to the developers, don't have to worry about the government knowing who they are talking with.

For the app to work, both people wanting to text or call each other must have the application. But when the application is used, the phone company will not know the identity or phone number of the other person on the line. It will only know that the caller used Seecrypt.