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September 27, 2014

NASA finds clear skies on exoplanet

Artist's concept of HAT-P-11b crossing in front of its star (Image: NASA/JPL-Caltech)

Artist's concept of HAT-P-11b crossing in front of its star (Image: NASA/JPL-Caltech)

In a display of interstellar teamwork, NASA’s Hubble, Spitzer and Kepler space telescopes have discovered clear skies and water vapor in the atmosphere of a Neptune-sized planet orbiting a star 120 light years from Earth. According to the space agency, this may not only provide insights into the formation of giant exoplanets, but also act as a new tool for detecting water on Earth-like planets orbiting other stars.

Astronomers like clear skies on Earth, because it makes it easier to look out of the atmosphere. They also like clear skies on other planets because it allows them to look in. Otherwise, they just end up looking at a load of cloud tops. In a very distant example of a nice day, astronomer found clear skies on HAT-P-11b; an exo-Neptune planet that orbits the orange dwarf star HAT-P-11 once every five days.

Located 120 light years distant in the constellation of Cygnus, HAT-P-11b is a hot world with a rocky core and gaseous atmosphere. According to NASA, this is the smallest planet on which any sort of molecules have been detected. Previously, molecules, including water vapor, have been detected in the atmospheres of Jupiter and super-Jupiter sized planets because of their size and less dense atmospheres. But HAT-P-11b is the smallest planet yet where water has been detected – nothing of its size has been within the range of current technology until now.

Artist's concept comparing the atmosphere of exoplanet HAT-P-11b (right) and how other exo...
Artist's concept comparing the atmosphere of exoplanet HAT-P-11b (right) and how other exoplanets seen until now may look (left) (Image: NASA/JPL-Caltech)

The technique used for peeking through the atmosphere is called transmission spectroscopy. This involves studying the light from the planet’s star as it passes through the planet’s atmosphere. Obviously, if that atmosphere is laden with clouds, the light won’t go through. Fortunately, HAT-P-11b’s atmosphere has clear skies in at least the higher altitudes. This clearness was demonstrated by the fact that the Hubble could detect the starlight.

Using the Hubble's Wide Field Camera 3, the team took spectroscope readings of the light passing through the planet’s atmosphere and compared it to that of the star. The differences would indicate the presence and nature of any molecules in the air around HAT-P-11b.

According to NASA, the team did detect water vapor, but water can be found in regions of cooler stars called “starspots,” which are analogous to sunspots. To eliminate the possibility that all they were seeing was water on HAT-P-11, the team used data from the Kepler and Spitzer telescopes. Since they can see in the infrared, they could determine the temperature of the star and concluded that any starspots present would be too hot for water, which would break down into its constituent atoms at too high a temperature.

A plot of the transmission spectrum for exoplanet HAT-P-11b (Image: NASA/ESA/STScI)

NASA says that HAT-P-11b has an atmosphere of water vapor, hydrogen, and other gases yet to be determined, and that the data will be helpful in learning more about the diversity of giant exoplanets and their formation. NASA plans to continue working to detect clear skies and water vapor on smaller and smaller planets with the goal of ultimately finding water on an Earth-like exoplanet using the James Webb telescope, which launches in 2018.

"The work we are doing now is important for future studies of super-Earths and even smaller planets, because we want to be able to pick out in advance the planets with clear atmospheres that will let us detect molecules," says Heather Knutson of the California Institute of Technology in Pasadena.

September 26, 2014

Hull-clinging robots could perform secret searches of smugglers' boats

MIT's prototype contraband-searching robot

MIT's prototype contraband-searching robot

Maritime smugglers will often hide contraband in false hulls or propeller shafts within their boats. While there are ways in which port authorities can search for such stashes, the smugglers often have time to ditch their illicit goods before those searches can be performed. However, what if there were stealthy, inexpensive, underwater hull-hugging robots that could check the boats out, without the crews even knowing they were there? That's just what a team at MIT is developing.

The current prototype robot was designed by mechanical engineering grad student Sampriti Bhattacharyya and her advisor, Prof. Harry Asada. Built mainly using a 3D printer, it's oval in shape (but with a flat bottom), and is described as being a little smaller than a football.

Half of its body is watertight, and contains its electronics – these include its control circuitry, rechargeable lithium battery, communications antenna, and inertial measurement unit. The latter is made up of three accelerometers and three gyroscopes, and is used to keep track of the robot's positioning as determined by its movements.

The other half, which is permeable, houses its propulsion system – this consists of six pumps that are each hooked up to a separate rubber output tube. Two of those tubes come out the back of the robot, pushing it in against the boat's hull as they vent water. The other two pairs are located at either end of the robot, pushing it forward or backward along the hull at a maximum speed of about one meter (3.3 ft) per second, and allowing it to make tight turns.

Although the prototype presently doesn't contain one, Bhattacharyya envisions the robots ultimately being equipped with ultrasound scanners. Fleets of them could be surreptitiously placed on the hulls of suspect vessels, where they would slide along the metal, checking for anomalous readings that might indicate hidden cargo underneath.

Using their communications systems, they could both coordinate their search patterns with one another, and transmit their readings to topside authorities. They would reportedly not produce a wake that might alert crew members to their presence, and could also be camouflaged using clumps of algae.

The prototype is able to run for about 40 minutes on one charge of its battery, although Sampriti plans on increasing that to 100 in the next version. One challenge, however, will involve finding a way of getting good-quality ultrasound readings while moving across the uneven, barnacle- and rivet-festooned hulls. Traditionally, ultrasound only works when maintaining contact with a smooth surface, or when the scanning distance is kept consistent. This could be overcome by establishing a hydrodynamic buffer – a sort of cushion of water – between the robot and the hull surface.

In any case, Bhattacharyya hopes that the final model will be relatively inexpensive – perhaps about US$600 – so that the technology proves more cost-effective than the use of existing underwater robots.

Octopus bacteria lamp glows when disturbed

Ambio is a new lamp concept that lights up using bioluminescent bacteria

Ambio is a new lamp concept that lights up using bioluminescent bacteria

The need to minimize the energy we use need not necessarily impact adversely on the form or function of a device. This premise is elegantly demonstrated by Ambio, a "bacterial lamp" created by designer Teresa van Dongen. Ambio merges sleek design with a soft glow created by bioluminescence.

Gizmag has featured lamps that use bioluminescent bacteria before, including the Philips Bio-Light and the Dino Pet night-light for children. The Ambio, however, is an example of how the concept might be employed for a more conventional home lamp.

Ambio features a tube that is half-filled with an artificial seawater medium containing th...

"Ambio balances two weights and a glass tube half-filled with an 'Artificial Seawater Medium' containing a carefully selected type of these unique luminescent species," explains van Dongen on her website. "Give the lamp a gentle push every so often and the weights will keep it moving and thus glowing."

The bacteria species used in Ambio is known as Photobacterium and is extracted from octopi. The luminescence is caused by a chemical reaction when the bacteria comes into contact with oxygen, hence the tube is only half-filled so as to facilitate this contact.

When Ambio is disturbed, the bacteria comes into contact with oxygen in the tube causing a...

The lamp would not be entirely practical now, as the bacteria would eventually die, but work is ongoing to find out how the lifespan of the bacteria can be prolonged for a possible next generation of Ambio.

The video below shows Ambio in use.

Band plays "world's first" gig with 3D-printed instruments

A picture of the band, from Lund University's Malmö Academy of Music, in sound-check

A picture of the band, from Lund University's Malmö Academy of Music, in sound-check

Though musicians could probably point to numerous exquisite examples of custom instruments with relative ease, we'd wager that few would compare to those produced by Olaf Diegel. Now the Lund University professor has taken his creations to the stage for what he claims is the world's first gig using 3D-printed instruments.

Diegel has been 3D printing since the mid-90s and began his ODD Guitars 3D-printed instrument company in 2011. As well as commercially-available guitars, Diegel has produced a variety of other instrument prototypes, including a drum kit and a saxophone.

"Musicians, strangely, they're very creative, but at the same time they're very conservative," says Diegel. "They first approach essentially a plastic guitar with a lot of suspicion, but then they have a play with it and they're completely amazed that it sounds and plays like a high quality electric guitar."

The gig featured instruments created by Olaf Diegel, including guitars and bass guitars, a...

The concert at Lund University featured a band made up of musicians from its Malmö Academy of Music. It featured instruments created by Diegel, including electric guitars and bass guitars, a drum kit and a keyboard. Diegel explains to Gizmag that the instruments were designed using the SolidWorks 3D computer aided design software package. This allows him to edit designs much like he would if he were using a graphics package.

When his designs are complete, Diegel sends them to Cubify, the printing service arm of 3D printer manufacturer 3D Systems. The final designs are printed by Cubify using industrial selective laser sintering systems, which are much more accurate and advanced than the 3D printers that can be bought for the home. Once the instruments parts have been printed and delivered to Diegel, they are assembled together with the rest of the (non-printed) instrument components.

A professor and Lund University, Sweden, claims to have staged the first concert with a ba...

"3D printing is still a comparatively expensive manufacturing process, so is only worth using if it adds value," Diegel tells Gizmag. "If I were making simple guitar shapes, it would be much more cost-effective to CNC machine them, for example. But the extreme complex details inside my guitars just couldn’t be made with any other manufacturing."

According to Diegel, it takes around 11 hours to print a guitar body and about the same again to paint it. A further day is spent on tasks such as assembling the components and setting the action. The whole process, including the design stage, can take from a matter of days up to a number of weeks depending on the complexity of the design.

In the video below, Diegel provides an introduction to the project.

September 25, 2014

Wearable skin and heart monitor changes color when there's cause for concern

The skin-like patch changes color as it detects changes in temperature of the skin's surfa...

The skin-like patch changes color as it detects changes in temperature of the skin's surface

Researchers from Northwestern University and the University of Illinois at Urbana-Champaign have developed a health monitor capable of tracking heart and skin condition while worn discretely on the skin. Measuring around 5 cm squared (0.8 in sq), the patch is designed to be inconspicuous and alert the user to conditions ranging from dry skin to cardiovascular problems.

The skin-like patch is intended to be worn around the clock, making its comfort a major design focus. It comprises 3,600 liquid crystals, each measuring around 0.5 mm squared that lay atop a stretchable substrate. When worn, these crystals serve as temperature points, monitoring temperature changes on the skin's surface.

By tracking these changes in temperature, the device can identify the wearer's blood flow rate, which is indicative of cardiovascular health, while also monitoring skin hydration. When temperature change is detected, the patch changes color to alert the user that something is amiss. An algorithm then turns the temperature data into decipherable health information, a process the researchers say takes around 30 seconds.

"One can imagine cosmetics companies being interested in the ability to measure skin’s dryness in a portable and non-intrusive way,” said Yonggang Huang, one of the senior researchers. "This is the first device of its kind.”

Electromagnetic waves in the air power the device's wireless heating system, which is used to gauge the thermal properties of the skin. The researchers claim with its 3,600 temperature points, the spatial resolution of the device is comparable to that of infrared technology, though with a much lower price tag and better portability.

“These results provide the first examples of ‘epidermal’ photonic sensors,” said John A. Rogers, the paper’s corresponding author and professor of materials science and engineering at the University of Illinois. “This technology significantly expands the range of functionality in skin-mounted devices beyond that possible with electronics alone.”

The research was published in the journal Nature Communications.