NASA’s Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named “Hottah.” (NASA)

The Curiosity rover has discovered an ancient stream bed that suggests water, possibly lots of it, once flowed on Mars.

In a new study,  scientists say their findings represent the first on-site evidence of sustained water flow on the Martian landscape. The discovery also supports the theory Mars would have once been able to host life.

Dawn Sumner, a co-author of the study, said  she and her colleagues used very basic geologic principles in making their discovery.  While examining high-resolution photographs of multiple outcrops of pebble-rich slabs  shot by Curiosity, they noticed some rounded pebbles.

“On the first day of my sedimentary class, I have the students measure grain size and the rounding,” said Sumner, who is a University of California-Davis geologist and professor. “It’s simple, and it’s important.”

Sumner said the pebbles’ rounded shape and granular size, along with other characteristics, can only form when pebbles are transported through water over long distances.

The pebbles, which were likely deposited more than two billion years ago, were discovered at three locations on Mars, known as Goulburn, Link and Hottah, which are located between the north rim of the planet’s Gale Crater and the base of a mountain located in the crater called Mount Sharp, about a quarter mile away from where Curiosity landed last summer.

In the foreground is the gravelly area around Curiosity’s landing site in Gale Crater. Mt. Sharp is seen in the distance. (NASA)

Sumner is also a co-investigator for the Mars Science Laboratory team and played an important role in selecting Gale Crater as Curiosity’s landing site.  She also helped coordinate the first scientific interpretations of what the rover saw during its first few days on the Red Planet, by controlling it with a computer to take photographs of its surroundings.

“The main reason we chose Gale Crater as a landing site was to look at the layered rocks at the base of Mount Sharp, about five miles away,” she said. “We knew there was an alluvial fan in the landing area, a cone-shaped deposit of sediment that requires flowing water to form. These sorts of pebbles are likely because of that environment. So while we didn’t choose Gale Crater for this purpose, we were hoping to find something like this.”

You can hear Dr. Sumner talk about her team’s discovery and the role geology is playing in the Curiosity’s goal of determining the “habitability” of Mars on this weekend’s radio edition of Science World – see right column for times and audio links.

Microscopic view of  Planococcus halocryophilus OR1 (McGill University)

A permafrost microbe has been discovered growing at –15°C, the coldest temperature ever reported for bacterial growth.

A team of scientists from Montreal’s McGill University made the discovery on Ellesmere Island, located in the Canadian High Arctic.

Researchers said they  found the living strain of bacteria growing in the extreme cold of the  permafrost, which may offer insight into possibilities of life existing beyond Earth.

The bacterium, Planococcus halocryophilus OR1, not only survives, but thrives in the permanently frozen sub-soil. Finding the microbe in the briny conditions of the Arctic could provide some hints about what it would take for microbial life to survive in conditions  found on the Saturn moon, Enceladus, or Mars, where similar frigid conditions are thought to exist.

The researchers examined about 200 separate types of microbes from the high Arctic before they found the microorganism that was best adapted to the harsh conditions of the Arctic permafrost.

”We believe that this bacterium lives in very thin veins of very salty water found within the frozen permafrost on Ellesmere Island,” said McGill professor Lyle Whyte who co-led the research team. “The salt in the permafrost brine veins keeps the water from freezing at the ambient permafrost temperature creating a habitable but very harsh environment. It’s not the easiest place to survive but this organism is capable of remaining active  to at least -25ºC in permafrost.”

To make their discovery, the research team studied the genomic sequence and other molecular characteristics of the P. halocryophilus OR1 microbe. The researchers found the bacterium adapts quite well to its bitter cold and salty environment, thanks to significant adjustments in its cell structure and function, as well as having increased amounts of cold-adapted proteins. Some of these cellular modifications also include changes to the membranes that envelop the microbe and protect it from its hostile environment.

Research team leaders Lyle Whyte (l) and Nadia Mykytczuk (r) (McGill University)

After studying the microbe’s genome sequence, the scientists also discovered the bacterium is unusual in other ways;  it seems to have the ability to maintain high levels of compounds within the bacterial cell that act like molecular antifreeze, keeping the microorganism from not only from freezing solid but protects it from the salty environment.

“I’m kind of proud of this bug. It comes from the Canadian High Arctic and is our cold temperature champion, but what we can learn from this microbe may tell us a lot about how similar microbial life may exist elsewhere in the solar system,” said research co-leader Nadia Mykytczuk.

The researchers agree concerned with one possibly troubling aspect of the microbe.  They think  the living microorganisms can harm the bitter cold environment of areas such as the high Arctic by increasing the amount of carbon dioxide emissions from the permafrost which is now melting due to what many scientists believe is global warming.

Bats use echolocation to navigate in the dark when hunting prey. (Steve Garner via Creative Commons/Flickr)

Humans have built-in biological sonar similar to bats and dolphins that could lead to a better quality of life for blind people and the visually impaired.

The international study suggests people have the ability to use echoes, or echolocation, a skill some animals  use to detect and find objects. Developing this ability could promote increased independence  for the blind and visually impaired.

The study, published in Hearing Research, looked at how the ability to hear echoes could help the blind with spatial awareness and navigation. Researchers also examined the impact hearing impairment has on echolocation as well as how to optimize a person’s echolocation capabilities.

Using a technique called virtual auditory space, which creates sounds that simulate movement, the researchers from the University of Southampton and the University of Cyprus, conducted a series of experiments with sighted and blind subjects.

“We wanted to determine unambiguously whether blind people, and perhaps even sighted people, can use echoes from an object to determine roughly where the object is located. We also wanted to figure out what factors facilitate and restrict people’s abilities to use echoes for this purpose in order to know how to enhance ability in the real world,” said Daniel Rowan, the study’s lead author.

The researchers found that, as long as they have good hearing, both those with and without sight have the potential to use echoes to locate objects, even if they have no previous experience with echolocation.  The study found that individuals must be able to hear high-frequency sounds – above 2 kHz – to effectively use echolocation.

Illustration of how a bat uses echolocation to find prey (Shung via Wikimedia Commons)

“Some people are better at this than others, and being blind doesn’t automatically confer good echolocation ability, though we don’t yet know why,” said Rowan. “Nevertheless, ability probably gets even better with extensive experience and feedback.”

Rowan also adds, “We also found that our ability to use echoes to locate an object gets rapidly worse with increasing distance from the object, especially when the object is not directly facing us. While our experiments purposely removed any influence of head movement, doing so might help extend ability to farther distances. Furthermore, some echo-producing sounds are better for determining where an object is than others, and the best sounds for locating an object probably aren’t the same as for detecting the object or determining what, and how far away, the object is.”

The study authors plan to extend their research to explore the use of echolocation to find objects in three-dimensional spaces.

They also want to examine why some blind people appear to be better at using this technique than others, including people who can see.

A malfunction could force an abrupt end to the Kepler Space Telescope’s planet-hunting mission.

Artist’s rendering of the Kepler space telescope. (NASA)

NASA received the unwelcome news last Sunday after discovering Kepler had malfunctioned and is currently operating in a self-protective “safe-mode” as it also did earlier this month. The US space agency made the news public this past Wednesday.

It appears at least one of Kepler’s four reaction wheels―onboard devices that precisely aim its telescopic instruments―is not working properly. Kepler needs at least three of the positioning devices to keep its aim true, allowing it to continue its mission, according to NASA.

Launched in 2009, Kepler was designed specifically to hunt for Earth-like planets that may support life elsewhere in the Universe.  It has revolutionized the study of extrasolar, or exoplanets, and has discovered about 130 worlds circling distant stars. Nearly 2,700 potential planets are still awaiting confirmation.

NASA scientists and technicians are working on ways to either repair Kepler’s malfunctioning devices, or to develop alternate methods to keep the spacecraft properly oriented.  If their efforts are unsuccessful, Kepler’s mission could end far sooner than planned.

NASA officials insist they won’t give up on the space telescope until it can no longer perform useful science.

One of the reaction wheels aboard the Kepler spacecraft (NASA)

Unlike the days when it could simply dispatch a space shuttle mission whenever the Hubble Space Telescope needed repairs, NASA must make the repairs and correct the problem by remote control from Earth.

The reason is because, unlike Hubble which is in Earth Orbit, Kepler is in orbit with the Sun and is about 65 million kilometers from Earth, or about the distance to Mars. That distance makes it impossible to send a manned or even unmanned repair mission to fix the ailing spacecraft.

However, there are two possible ways to salvage the spacecraft, according to Scott Hubbard, a former NASA official who helped guide Kepler throughout much of its building stage and is now a consulting professor at Stanford University.

“One is that they could try turning back on the reaction wheel that they shut off a year ago,” he said. “It was putting metal on metal, and the friction was interfering with its operation, so you could see if the lubricant that is in there, having sat quietly, has redistributed itself, and maybe it will work.”

The other scheme, which has never been tried,  according to Hubbard, involves using thrusters and the solar pressure exerted on the solar panels to try and act as a third reaction wheel and provide additional pointing stability.

“I haven’t investigated it,” Hubbard said, “but my impression is that it would require sending a lot more operational commands to the spacecraft.”

Artist’s concept of Kepler-22b, a planet known to circle in the habitable zone of a sun-like star, which was discovered in 2011. (NASA)

There seems to be little possibility that Kepler could continue to make useful observations of the cosmos, conducting experiments that perhaps wouldn’t depend on it having to precisely aim its instruments

“People have asked about using it to find near-Earth objects, or asteroids,” Hubbard said. “Kepler carries a photometer, not a camera, that looks at the brightness of stars, and so its optics deliberately defocus light from stars to create a nice spread of light on the detector, which is not ideal for spotting asteroids.”

Hubbard said that since the space telescope wasn’t built as a camera, using Kepler as an asteroid detector will need to be studied.

“I would say that I’m skeptical,” he said.  “That said, certainly between Ames Research Center and the Jet Propulsion Laboratory, they’ve got the best people in the world working on it.”

Meanwhile as repair and workaround solutions are being sought, the Kepler team’s priority right now is to complete preparations to put the spacecraft into a resting state similar to hibernation that minimizes fuel usage while providing a continuous X-band downlink.  The X-band is a set of microwave frequencies and portions of it have been set aside to be used exclusively for deep space telecommunications.

The software required to do this was uploaded to the spacecraft last week.

(Garry Wilmore via Creative Commons/Flickr)

Laughter can be a valuable communications tool; it can indicate ridicule, humor, joy or maybe just a physical response to being tickled.  German scientists have found these different laugh responses are  handled by different networks in our brains, depending on the specific context of the laughter.

The different patterns of brain connectivity brought on by the various forms of laughter may play an important role in influencing cognitive functions regarding health and disease.

The study’s findings could eventually lead to treatments for people with anxiety or other similar conditions, according to a blog by Brett Smith.

“Laughing at someone and laughing with someone leads to different social consequences,” said Dirk Wildgruber from the University of Tuebingen “Specific cerebral connectivity patterns during perception of these different types of laughter presumably reflect modulation of attentional mechanisms and processing resources.”

Did you know that animals also laugh? But their laughter is a way to socially bond with each other and is based on a primitive reflex similar to tickling.  Human laughter has evolved beyond those simple roots, according to the researchers.

(Sean Dreilinger via Creative Commons/Flickr)

While most people do laugh when tickled, so called social laughter in humans can also be used to convey happiness, derision or other conscious messages to those around us. The researchers involved with this study focused on  participants’ neural responses when they listened to three different kinds of laughter: ones that reflected joy, taunting and tickling.

They found that when people heard sounds of happy or teasing laughter, regions of the brain that process more complex social information were activated. However, those same brain regions were not stimulated by laughter triggered by tickling.

Tickling laughter triggered regions of the brain that are more sensitive to a higher degree of acoustic complexity.

Researchers found the dynamic changes brought on by  various kinds of laughter activated and connected with different regions of the brain.

A computer-generated image of the light distortions created by a black hole. (Credit: Alain Riazuelo, IAP/UPMC/CNRS)

A cosmic flash generated by a dying star might allow scientists to see something they’ve never witnessed before – the birth of a black hole.

A black hole is a celestial object that is so dense not even light can escape its intense gravitational pull. This phenomenon occurs when a dying star runs out of fuel and collapses under the weight of its own gravity.

A dying star that produces a black hole normally does so without a bang or flash, seeming to simply disappear from the sky in an event some scientists call an “un-nova.”

“You don’t see a burst,” said Tony Piro, a postdoctoral scholar at the California Institute of Technology (Caltech). “You see a disappearance.”

Some dying stars do explode as powerful gamma-ray bursts before becoming black holes, but scientists say that’s quite rare and requires very unusual conditions.

“We don’t think most run-of-the-mill black holes are created that way,” said Piro.

But, according to his new analysis published in Astrophysical Journal Letters, a dying star might emit a cosmic flash which could alert researchers that a black hole is about to be formed.

That flash would bright enough to be seen in nearby by galaxies, according to Piro.

“That flash is going to be very bright, and it gives us the best chance for actually observing that this event occurred,” he said. “This is what you really want to look for.”

Piro says astronomers working with sky surveys should be able to observe one of these cosmic flashes about once a year.

This is a prototype of GROVER, without its solar panels. The laptop in the picture was only used for testing purposes. (Gabriel Trisca, Boise State University)

NASA‘s newest rover could help scientists better understand changes in the massive Greenland ice sheet.

Last summer, higher-than-normal temperatures caused surface melting across about 97 percent of the ice sheet.

Scientists expect the robot to detect the layer of the sheet, which is buried beneath two miles of ice, that formed after last year’s extreme melt event.

The space agency plans to test its new prototype robot rover called GROVER, an acronym for both Greenland Rover and Goddard Remotely Operated Vehicle for Exploration and Research, through June 8, when it sets off from the National Science Foundation’s research station called Summit Camp.

Using a ground-penetrating radar system, the solar-powered robot will study how snow accumulates as it adds layer after layer to the ice sheet over time.

“Robots like GROVER will give us a new tool for glaciology studies,” said Lora Koenig, a glaciologist at Goddard Space Flight Center in Greenbelt, Maryland and science advisor on the project.

GROVER was built by students who took part in Goddard’s summer engineering boot camps in 2010 and 2011, who told Koenig they wanted to build a rover to help her study snow accumulation on ice sheets.

Students participate in a 2011 NASA Goddard summer engineering boot camp test two prototypes of GROVER at a beach in Asseteague Island, Md. (NASA)

NASA describes GROVER, which stands nearly two meters tall, as tank-like in appearance.  The robot weighs about 383 kilograms and will be able to crawl across the icy terrain at an average speed of two kilometers an hour on a pair of re-purposed snowmobile tracks.

The solar panels mounted on GROVER form an inverted V. This unique configuration allows the panels to collect energy from the sun as well as from sunlight reflected off the ice sheet.

The sun never goes down during the Arctic summer, so GROVER will be able to constantly refuel, allowing it to work longer, gathering more information than perhaps a human riding on a snowmobile.

And, since it’s solely powered by the sun, the rover should operate in the unspoiled polar environment without polluting the air and environment.

GROVER has other advantages. NASA expects to save money since the polar rovers cost less than the aircraft and satellites usually used to gather data.

In June, GROVER will get a partner, another robot called Cool Robot, which was developed at Dartmouth College in New Hampshire. NASA says the National Science Foundation-funded rover will be able to tow a variety of instrument packages needed to conduct glaciological and atmospheric sampling studies.

Watch this NASA video to see GROVER in action (NASA)

The World’s Smallest Stop-action Movie (IBM)

Bigger is often better in Hollywood, but IBM is drawing lots of attention for making the smallest movie ever.

A Boy and His Atom is a stop-motion, animated movie made with thousands of precisely positioned atoms in nearly 250 motion picture frames.  The folks at Guinness World Records®  verified that it’s the smallest stop-action movie  ever made.

The storyline, set to a lively musical track, follows a boy who makes friends with a single atom. Together, they go on a spirited journey that has them dancing, playing catch with each other, and bouncing on a trampoline.

Poster for “A Boy and His Atom,” the world’s smallest movie. (IBM)

IBM says  its little movie is a unique way of conveying science outside the research community.

“Capturing, positioning and shaping atoms to create an original motion picture on the atomic-level is a precise science and entirely novel,” said Andreas Heinrich, principle investigator at IBM Research. “At IBM, researchers don’t just read about science, we do it. This movie is a fun way to share the atomic-scale world while opening up a dialogue with students and others on the new frontiers of math and science.”

The atoms in the animation were manipulated with an IBM-invented, award-winning scanning tunneling microscope.

“This Nobel Prize winning tool was the first device that enabled scientists to visualize the world all the way down to single atoms,” said Christopher Lutz, a scientist with IBM Research. “It weighs two tons, operates at a temperature of negative 268 degrees Celsius and magnifies the atomic surface over 100 million times. The ability to control the temperature, pressure and vibrations at exact levels makes our IBM Research lab one of the few places in the world where atoms can be moved with such precision.”

Researchers used a standard computer to remotely operate the microscope, manipulating a super-sharp needle that hovered about one nanometer, or one billionth of a meter, above a copper surface, which allowed the scientists to “feel” the atoms.

The scanning tunneling microscope used to manipulate atoms to create the world’s smallest movie. (IBM)

At such a minute distance, the needle was able to physically attract atoms and molecules on the surface and then move them to precisely specified locations on the surface.

According to IBM, the moving atom makes a unique sound that is critical feedback in determining how many positions it’s actually moved.

The scientists created and photographed 242 still images of stop-action motion with the nearly 10,000 individually placed atoms.  Those photos were then rendered into a video that’s about a minute and eight seconds long.

The IBM researchers created the film in part to demonstrate technology that could be used in the future to create computer storage systems, based on atomic-scale memory, that would be capable of storing massive amounts of data.