Friday, March 30, 2012

The Cool Clouds of Carina



Observations made with the APEX telescope in submillimetre-wavelength light at a wavelength of 870 µm reveal the cold dusty clouds from which stars form in the Carina Nebula. This site of violent star formation, which plays host to some of the highest-mass stars in our galaxy, is an ideal arena in which to study the interactions between these young stars and their parent molecular clouds. The APEX observations, made with its LABOCA camera, are shown here in orange tones, combined with a visible light image from the Curtis Schmidt telescope at the Cerro Tololo Interamerican Observatory. The result is a dramatic, wide-field picture that provides a spectacular view of Carina's star formation sites. The nebula contains stars equivalent to over 25 000 Suns, and the total mass of gas and dust clouds is that of about 140 000 Suns. Credit: ESO/APEX/T. Preibisch et al. (Submillimetre); N. Smith, University of Minnesota/NOAO/AURA/NSF (Optical). Tap © to visit the web site.

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Wednesday, March 28, 2012

Antennae Galaxies composite of ALMA and Hubble observations

The Antennae Galaxies (also known as NGC 4038 and 4039) are a pair of distorted colliding spiral galaxies about 70 million light-years away, in the constellation of Corvus (The Crow). This view combines ALMA observations, made in two different wavelength ranges during the observatory's early testing phase, with visible-light observations from the NASA/ESA Hubble Space Telescope. The Hubble image is the sharpest view of this object ever taken and serves as the ultimate benchmark in terms of resolution. ALMA observes at much longer wavelengths which makes it much harder to obtain comparably sharp images. However, when the full ALMA array is completed its vision will be up to ten times sharper than Hubble. Most of the ALMA test observations used to create this image were made using only twelve antennas working together — far fewer than will be used for the first science observations — and much closer together as well. Both of these factors make the new image just a taster of what is to come. As the observatory grows, the sharpness, speed, and quality of its observations will increase dramatically as more antennas become available and the array grows in size. This is nevertheless the best submillimetre-wavelength image ever taken of the Antennae Galaxies and opens a new window on the submillimetre Universe. While visible light — shown here mainly in blue — reveals the newborn stars in the galaxies, ALMA's view shows us something that cannot be seen at those wavelengths: the clouds of dense cold gas from which new stars form. The ALMA observations — shown here in red, pink and yellow — were made at specific wavelengths of millimetre and submillimetre light (ALMA bands 3 and 7), tuned to detect carbon monoxide molecules in the otherwise invisible hydrogen clouds, where new stars are forming. Massive concentrations of gas are found not only in the hearts of the two galaxies but also in the chaotic region where they are colliding. Here, the total amount of gas is billions of times the mass of the Sun — a rich reservoir of material for future generations of stars. Observations like these will be vital in helping us understand how galaxy collisions can trigger the birth of new stars. This is just one example of how ALMA reveals parts of the Universe that cannot be seen with visible-light and infrared telescopes. Credit: ALMA (ESO/NAOJ/NRAO). Visible light image: the NASA/ESA Hubble Space Telescope. Tap © to visit the web site.

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Monday, March 26, 2012

Smoke Without Fire: a Different View of the Cigar Galaxy

This image shows the most detailed view ever of the core of Messier 82 (M 82), also known as the Cigar Galaxy. Rich with dust, young stars and glowing gas, M 82 is both unusually bright and relatively close to Earth. The starburst galaxy is located around 12 million light-years away in the constellation of Ursa Major (The Great Bear). This is not the first time Hubble has imaged the Cigar Galaxy. Previous images (for example heic0604) show a galaxy ablaze with stars. Yet this image looks quite unlike them, and is dominated instead by glowing gas and dust, with the stars almost invisible. Why such a difference? The new image is more detailed than previous Hubble observations – in fact, it is the most detailed image ever made of this galaxy. But the reason it looks so dramatically different is down to the choices astronomers make when designing their observations. Hubble's cameras do not see in colour: they are sensitive to a broad range of wavelengths which they image only in greyscale. Colour pictures can be constructed by passing the light through different coloured filters and combining the resulting images, but the choice of filters makes a big difference to the end result. Using filters which allow through relatively broad bands of colours, similar to those our eyes see, results in natural-looking colours and bright stars, as starlight shines brightly across the spectrum. Using filters transparent only to the wavelengths emitted by specific chemical elements, as in this image, isolates the light from glowing gas clouds, while blocking out much of the starlight. This explains why the stars appear faint in this image, and why the dust lanes are sharply silhouetted against the brightly glowing gas clouds. The image shows the light emitted by sulphur (shown in red), visible and ultraviolet light from oxygen (shown green and blue, respectively), and light from hydrogen (cyan). The field of view is approximately 2.7 by 2.7 arcminutes. Credit: ESA/Hubble & NASA. Tap © to visit the web site.

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Thursday, March 22, 2012

Io's Atmosphere and the Io Plasma Torus

In spite of the large quantities of gas ejected by its many volcanoes, Io does not have a significant atmosphere. Io's average surface temperature is so low, (about 100 to 110 K (-280 to -290 degrees Fahrenheit), that much of the released gas condenses back onto the surface as frost deposits. The thin atmosphere that does exist is composed primarily of sulfur dioxide gas.

Some molecules of gas do escape, however, and Io is surrounded by a cloud of sodium, potassium, and oxygen atoms. The sodium cloud, visible in this image, is the most easily observed. The source of the sodium remains a mystery to scientists because it has not yet been detected anywhere on Io's surface. Recently, the element chlorine was also discovered. This finding leads scientists to believe that sodium chloride, or common table salt, may exist on Io and influence its violent volcanic activity. Prior to this discovery, only sulfur, oxygen, sodium, and potassium atoms were observed escaping Io's atmosphere.

Two common compounds of chlorine are sodium chloride, table salt, and hydrogen chloride, which is a colorless gas emitted by volcanoes. Scientists do not yet know if the chlorine is emitted from Io's volcanoes, or comes from the breakup salt on Io's surface by charged particles in the plasma torus. How salt might form on Io is unclear. It may be that there are subsurface rivers or aquifers supplying the fuel for Io's volcanoes that carry dissolved salts, or the salts may be the result of chemical reactions in the atmosphere.

 

Io plasma torus

Within Jupiter's magnetosphere, there is a significant amount of hot, ionized gas, or plasma. This plasma moves along with Jupiter's rotating magnetic field, sweeping charged particles off the surfaces of its moons as it passes them. Io has a particularly significant impact on Jupiter's magnetosphere. Io's volcanoes continually expel an enormous amount of particles into space, and these are swept up by Jupiter's magnetic field at a rate of 1,000 kg/sec. This material becomes ionized in the magnetic field and forms a doughnut-shaped track around Io's orbit called the Io Plasma Torus.

[...]


http://www.planetaryexploration.net/jupiter/io/io_plasma_torus.html

Has anyone else ever noticed the similarities between the magnetosphere's plasma torus and a fleur de lis?

http://i156.photobucket.com/albums/t39/ioanacangeopol/fleurdelis3.jpg

Wednesday, March 21, 2012

Planet Mercury Even Weirder Than We Thought

Surface Heights

New data suggests that Mercury has undergone much more dynamic processes than previously believed and that its core is unlike any of the other rocky planets in our solar system.

NASA's MESSENGER spacecraft, which has been in orbit around the solar system's smallest and innermost planet for just over a year, has beamed back plenty of surprises for scientists here on Earth.

"I thought the surface of Mercury would turn out to be complex and the interior simple," said planetary scientist Maria Zuber of MIT, who is a member of the MESSENGER team and co-author of two new papers on the planet that appear March 21 in Science. "Instead, our data has been such a surprise that we kept thinking we were interpreting it wrong."

Mercury's tiny size and heavily cratered surface suggested that the planet cooled into an inert lump soon after its formation 4.5 billion years ago. The two new papers show that the planet had active geologic and tectonic processes occurring until at least the planet's middle age, around 2 billion years ago.

[...]

http://feeds.wired.com/~r/wired/index/~3/q0nT-Twj3aI/

University Makes 80,000 Einstein Documents Publicly Available

"The Hebrew University of Jerusalem has scanned in some 80,000 of Albert Einstein's documents. According to the university's press release, the documents cover more than just scientific matters. The broad range of subjects include his solution to the Jewish-Arab conflict, a postcard to his mother, and a letter from one of his mistresses asking for assistance getting to America. Some documents have been translated and annotated and are completely searchable."

Read more of this story at Slashdot.

Human wings: The green answer to air travel

Forget subways, trains, and bikes — those are old hat compared to what we're about to tell you. Meet the new green form of transportation: strapping on human bird wings and flying through the air with the greatest of ease.

In what is possibly the coolest invention since Icarus, Dutch inventor Jarno Smeets crafted human wings that actually work. (WE HOPE. It's possible this video is an elaborate and awesome fake, but do you really want to live in that world?) Smeets successfully flapped his wings and flew for about 60 seconds, becoming the first man in history to fly like an eagle … fly right into the future. Or in this case, fly like an albatross, which is the bird that Smeets says inspired his design.

Smeets MacGyvered his wings by stitching together kite fabric and windsurfer masts. To actually control his flight and generate enough power for lift-off, Smeets used two Wii controllers, smartphone accelerometers, and Turnigy motors. The wings, which boast a pretty significant span, weighed only 37 ounces.

While flapping his arms generated about 5 percent of the necessary power to achieve lift, the other 95 percent came from motors that provided 2,000 Watts of continuous power. The entire system is a wireless (haptic) concept, meaning that with the addition of video game controllers and smartphone technology, he was able to use his arms to control the contraption and navigate a flight that lasted about 60 seconds.

Sure, it might be sort of ridiculous to see the skies loaded with folks flapping to work. But think how cool you'll sound when you say, "No thanks guys, I don't need a ride. I brought my HUMAN BIRD WINGS!"

Just try not to fly too close to the sun...


Original Page: http://grist.org/list/human-wings-the-green-answer-to-air-travel/

Monday, March 19, 2012

A Laser Beam Towards the Milky Way's Centre



In mid-August 2010 ESO Photo Ambassador Yuri Beletsky snapped this amazing photo at ESO's Paranal Observatory. A group of astronomers were observing the centre of the Milky Way using the laser guide star facility at Yepun, one of the four Unit Telescopes of the Very Large Telescope (VLT). Yepun's laser beam crosses the majestic southern sky and creates an artificial star at an altitude of 90 km high in the Earth's mesosphere. The Laser Guide Star (LGS) is part of the VLT's adaptive optics system and is used as a reference to correct the blurring effect of the atmosphere on images. The colour of the laser is precisely tuned to energise a layer of sodium atoms found in one of the upper layers of the atmosphere — one can recognise the familiar colour of sodium street lamps in the colour of the laser. This layer of sodium atoms is thought to be a leftover from meteorites entering the Earth's atmosphere. When excited by the light from the laser, the atoms start glowing, forming a small bright spot that can be used as an artificial reference star for the adaptive optics. Using this technique, astronomers can obtain sharper observations. For example, when looking towards the centre of our Milky Way, researchers can better monitor the galactic core, where a central supermassive black hole, surrounded by closely orbiting stars, is swallowing gas and dust. The photo, which was chosen as Astronomy Picture of the Day for 6 September 2010 and Wikimedia Picture of the Year 2010, was taken with a wide-angle lens and covers about 180 degrees of the sky. Credit: ESO/Y. Beletsky. Tap © to visit the web site.

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Thursday, March 15, 2012

Preview of a Forthcoming Supernova

At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. In the first decades of the century, it became brighter and brighter, until, by April 1843, it was the second brightest star in the sky, outshone only by Sirius (which is almost a thousand times closer to Earth). In the years that followed, it gradually dimmed again and by the 20th century was totally invisible to the naked eye. The star has continued to vary in brightness ever since, and while it is once again visible to the naked eye on a dark night, it has never again come close to its peak of 1843. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star. Although 19th century astronomers did not have telescopes powerful enough to see the 1843 outburst in detail, its effects can be studied today. The huge clouds of matter thrown out a century and a half ago, known as the Homunculus Nebula, have been a regular target for Hubble since its launch in 1990. This image, taken with the Advanced Camera for Surveys High Resolution Channel is the most detailed yet, and shows how the material from the star was not thrown out in a uniform manner, but forms a huge dumbbell shape. Eta Carinae is not only interesting because of its past, but also because of its future. It is one of the closest stars to Earth that is likely to explode in a supernova in the relatively near future (though in astronomical timescales the "near future" could still be a million years away). When it does, expect an impressive view from Earth, far brighter still than its last outburst: SN 2006gy, the brightest supernova ever observed, came from a star of the same type. This image consists of ultraviolet and visible light images from the High Resolution Channel of Hubble's Advanced Camera for Surveys. The field of view is approximately 30 arcseconds across. Credit: ESA/Hubble & NASA. Tap © to visit the web site.

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Centaurus A

Colour composite image of Centaurus A, revealing the lobes and jets emanating from the active galaxy's central black hole. This is a composite of images obtained with three instruments, operating at very different wavelengths. The 870-micron submillimetre data, from LABOCA on APEX, are shown in orange. X-ray data from the Chandra X-ray Observatory are shown in blue. Visible light data from the Wide Field Imager (WFI) on the MPG/ESO 2.2 m telescope located at La Silla, Chile, show the background stars and the galaxy's characteristic dust lane in close to "true colour". Credit: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray). Tap © to visit the web site.

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Neutrino message sent through ground

Binary communications, through the Earth, Morse code style. 

For the first time, scientists have used neutrinos – the exotic fundamental particles that routinely pass right through Earth – to send a message through the ground.

Researchers have long been intrigued by the communication possibilities of neutrinos, because these particles can easily travel through matter, including a planet, without stopping, slowing down or being misdirected.

Neutrinos are extremely tiny particles with almost zero mass and neutral charge. Thus they are impervious to electromagnetic forces and respond very weakly to gravity. They almost never collide with other particles, generally passing straight through the atoms that make up matter.

Now, scientists have successfully harnessed neutrinos to send a message from one place to another, spelling out the word "neutrino" in a particle binary code

more here:
http://www.msnbc.msn.com/id/46748654/ns/...e-science

Absolutely mindblowing video shot from the Space Shuttle during launch



Drop whatever you're doing and watch this. NASA has released videos shot from onboard the Space Shuttle's Solid Rocket Boosters in the past, but you've never seen one prepared as masterfully as this.
For one thing, the footage was shot in high definition, so the image is exceptionally clear. But what puts this video head and shoulders above most other rocketcams is the sound. The audio has been remastered by the folks over at Skywalker Sound (yes, that Skywalker Sound), and the final product is nothing short of incredible.
Michael Interbartolo — who used to work on the Shuttle Program at Mission Control in Houston — had this to say about the video when he posted it to Google+ earlier this morning:
Just got this from the guys at Glenn who are finalizing the new special edition DVD/BluRay version of Ascent: Commemorating Shuttle which this will be an extra on. The video is shot from the Solid Rocket Booster Perspective up and down with enhanced sound thanks to Ben Burtt's son and the folks at Skywalker Sound. The team is still trying to figure out how to release this all to the public, but for now enjoy an exclusive first look. +NASA youtube doesn't even have the video.
Try to let what you're witnessing sink in. See those numbers flying past in the upper right hand corner? That's the Shuttle's airspeed. See that gleam of light against the inky backdrop of space at 2:08 and 3:11? That's the Shuttle continuing on its flight path into low Earth orbit. Hear the eerie rattling, haunting moans, and weird dinosaur noises? That's what it sounds like to be a Solid Rocket Booster, falling to Earth from an altitude of 150,000 feet.
[Michael Interbartolo via Bad Astronomy]

Absolutely mindblowing video shot from the Space Shuttle during launch

Tuesday, March 13, 2012

they just left off a word

A common misconception, perpetuated by those who are interested in perpetuating such faulty information, regarding electric vehicles is that they are somehow more "green" or "efficient" than their internal-combustion-engine equivalents. This is incorrect – it is not that "green" vehicles pollute less; they simply pollute less here:

Chris Cherry, assistant professor in civil and environmental engineering, and graduate student Shuguang Ji, analyzed the emissions and environmental health impacts of five vehicle technologies in 34 major Chinese cities, focusing on dangerous fine particles. What Cherry and his team found defies conventional logic: electric cars cause much more overall harmful particulate matter pollution than gasoline cars.

"An implicit assumption has been that air quality and health impacts are lower for electric vehicles than for conventional vehicles," Cherry said. "Our findings challenge that by comparing what is emitted by vehicle use to what people are actually exposed to. Prior studies have only examined environmental impacts by comparing emission factors or greenhouse gas emissions."

Particulate matter includes acids, organic chemicals, metals, and soil or dust particles. It is also generated through the combustion of fossil fuels.

The basic premise is that particulate matter is getting into the air at the power plants generating the electricity for those electric vehicles, and it is doing so at a significantly higher volume-per-vehicle than the ICE cars running around; as such, people in densely-populated areas breathe easier, while the areas around power plants make up for the difference. In other words, NIMBY, with the back yards being in the cities, and the eventual location of the pollution being "fly-over" areas.

Now, obviously, our power grid is very different from China's – only 70% of our power comes from fossil fuels, with coal accounting for 65% of that, compared to China's 85% and 90% numbers, respectively, so the net impact of a single electric vehicle on our country's total pollution output will be at least 17% smaller than China's, but the underlying premises probably still hold true.

As I have repeatedly said before, I have no significant problems with the notions of electric cars – being an engineer and science fiction addict, I cannot help but to like them. However, they are patently an immature technology, they massively fail on the cost-benefit analysis, and they are nowhere near ready for the mainstream use they are being forced into… and that is being forced upon us. And, apparently, until such time as our electric grid is mostly fed by systems that pollute in more containable, controllable fashions than fossil fuels (like nuclear power), they are not going to be any more "green" than anything else rolling around on the highways.

I would wonder how this news will impact those folks who were suckered into buying oversized, undercapable golf carts on the promise of their being "green", but something tells me facts like these will not penetrate their personal clouds of smug.

Original Page: http://www.wallsofthecity.net/2012/03/they-just-left-off-a-word.html

Work hours, sleep, and safety

National Sleep Awareness Week might have been last week, but many of us are feeling the importance of shuteye this week, as we struggle to drag ourselves out of bed at what feels like an inappropriate hour. While Daylight Saving Time may get the blame for sleepiness this week, though, there are important year-round factors that cause fatigue. In honor of National Sleep Awareness Week, the National Institute for Occupational Safety and Health's NIOSH Science Blog published two posts about the impact of work demands on sleep. Claire Caruso and Roger Rosa start off by highlighting the challenges of long hours and shift work:

[...]

Read the rest of this post...

Messier 78: a reflection nebula in Orion



This new image of the reflection nebula Messier 78 was captured using the Wide Field Imager camera on the MPG/ESO 2.2-metre telescope at the La Silla Observatory, Chile. This colour picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through a filter that isolates light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively. Credit: ESO/Igor Chekalin. Tap © to visit the web site.

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