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Planetary Nebula: Abell 33

Astronomers using ESO’s Very Large Telescope in Chile have captured this eye-catching image of planetary nebula Abell 33. Created when an aging star blew off its outer layers, this beautiful blue bubble is, by chance, aligned with a foreground star, and bears an uncanny resemblance to a diamond engagement ring. This cosmic gem is unusually symmetric, appearing to be almost perfectly circular on the sky. Caption: ESOESO

Did Vitamin B3 Come From Space?:

Ancient Earth might have had an extraterrestrial supply of vitamin B3 delivered by carbon-rich meteorites, according to a new analysis by NASA-funded researchers. The result supports a theory that the origin of life may have been assisted by a supply of key molecules created in space and brought to Earth by comet and meteor impacts.

“It is always difficult to put a value on the connection between meteorites and the origin of life; for example, earlier work has shown that vitamin B3 could have been produced non-biologically on ancient Earth, but it’s possible that an added source of vitamin B3 could have been helpful,” said Karen Smith of Pennsylvania State University in University Park, Pa. “Vitamin B3, also called nicotinic acid or niacin, is a precursor to NAD (nicotinamide adenine dinucleotide), which is essential to metabolism and likely very ancient in origin.” Smith is lead author of a paper on this research, along with co-authors from NASA’s Goddard Space Flight Center in Greenbelt, Md., now available online in the journal Geochimica et Cosmochimica Acta.

This is not the first time vitamin B3 has been found in meteorites. In 2001 a team led by Sandra Pizzarello of Arizona State University, in Tempe discovered it along with related molecules called pyridine carboxylic acids in the Tagish Lake meteorite.

In the new work at Goddard’s Astrobiology Analytical Laboratory, Smith and her team analyzed samples from eight different carbon-rich meteorites, called “CM-2 type carbonaceous chondrites” and found vitamin B3 at levels ranging from about 30 to 600 parts-per-billion. They also found other pyridine carboxylic acids at similar concentrations and, for the first time, found pyridine dicarboxylic acids.

“We discovered a pattern – less vitamin B3 (and other pyridine carboxylic acids) was found in meteorites that came from asteroids that were more altered by liquid water. One possibility may be that these molecules were destroyed during the prolonged contact with liquid water,” said Smith. “We also performed preliminary laboratory experiments simulating conditions in interstellar space and showed that the synthesis of vitamin B3 and other pyridine carboxylic acids might be possible on ice grains.”

Scientists think the solar system formed when a dense cloud of gas, dust, and ice grains collapsed under its own gravity. Clumps of dust and ice aggregated into comets and asteroids, some of which collided together to form moon-sized objects or planetesimals, and some of those eventually merged to become planets.

Space is filled with radiation from nearby stars as well as from violent events in deep space like exploding stars and black holes devouring matter. This radiation could have powered chemical reactions in the cloud (nebula) that formed the solar system, and some of those reactions may have produced biologically important molecules like vitamin B3.

Asteroids and comets are considered more or less pristine remnants from our solar system’s formation, and many meteorites are prized samples from asteroids that happen to be conveniently delivered to Earth. However, some asteroids are less pristine than others. Asteroids can be altered shortly after they form by chemical reactions in liquid water. As they grow, asteroids incorporate radioactive material present in the solar system nebula. If enough radioactive material accumulates in an asteroid, the heat produced as it decays will be sufficient to melt ice inside the asteroid. Researchers can determine how much an asteroid was altered by water by examining chemical and mineralogical signatures of water alteration in meteorites from those asteroids.

When asteroids collide with meteoroids or other asteroids, pieces break off and some of them eventually make their way to Earth as meteorites. Although meteorites are valued samples from asteroids, they are rarely recovered immediately after they fall to Earth. This leaves them vulnerable to contamination from terrestrial chemistry and life.

The team doubts the vitamin B3 and other molecules found in their meteorites came from terrestrial life for two reasons. First, the vitamin B3 was found along with its structural isomers – related molecules that have the same chemical formula but whose atoms are attached in a different order. These other molecules aren’t used by life. Non-biological chemistry tends to produce a wide variety of molecules — basically everything permitted by the materials and conditions present — but life makes only the molecules it needs. If contamination from terrestrial life was the source of the vitamin B3 in the meteorites, then only the vitamin should have been found, not the other, related molecules.

Second, the amount of vitamin B3 found was related to how much the parent asteroids had been altered by water. This correlation with conditions on the asteroids would be unlikely if the vitamin came from contamination on Earth.

The team plans to conduct additional interstellar chemistry experiments under more realistic conditions to better understand how vitamin B3 can form on ice grains in space. “We used pyridine-carbon dioxide ice in the initial experiment,” said Smith. “We want to add water ice (the dominant component of interstellar ices) and start from simpler organic precursors (building-block molecules) of vitamin B3 to help verify our result.”

Drunkenly Wobbling Planets Could Make Good Homes For Humans:

A drunken planet that’s reeling all over the place could actually be a better place for life to spring up, according to a new modelling study.

Astronomers at the University of WashingtonWeber State University and NASA have found that a fluctuating tilt in a planet’s orbit doesn’t stop the world from supporting life – in fact, it might actually help.

With odd pivots in their orbit, these “tilt-a-worlds” would be leaning one way and then another, which would actually expose their surfaces to more even heat from their suns. That could mean that planets further out from their stars, outside the commonly known habitable zone, could still be kept from turning into icy glacier-locked worlds.

“Planets like these are far enough from their stars that it would be easy to write them off as frozen, and poor targets for exploration, but in fact, they might be well-suited to supporting life,” said Shawn Domagal-Goldman, an astrobiologist at NASA’s Goddard Space Flight Centre. “ This could expand our idea of what a habitable planet looks like and where habitable planets might be found .”

Tilted orbits might make some planets wobble like a top that's almost done spinning, an effect that could maintain liquid water on the surface. (Credit: NASA's Goddard Space Flight Centre)Tilted orbits might make some planets wobble like a top that’s almost done spinning, an effect that could maintain liquid water on the surface. (Credit: NASA’s Goddard Space Flight Centre)

In their model, the scientists looked at planets that have the same mass as Earth, orbit a sun-like star and have one or two gas giants orbiting nearby. Those massive planets can pull a world’s axis of rotation with their huge gravitational effects, changing the orientation within tens to hundreds of thousands of years – a mere blink of an eye in geological terms.

Such a tilt-a-world becomes potentially life-supporting because the spin would cause the poles to occasionally point at their sun, melting their ice caps.

“Without this sort of ‘home base’ for ice, global glaciation is more difficult,” said UW astronomer Rory Barnes. “So the rapid tilting of an exoplanet actually increases the likelihood that there might be liquid water on a planet’s surface.”

Wobbling worlds might seem far-fetched, especially to us in a system where all the planets are on roughly the same plane in space. But researchers have already spotted planetary systems where t’s happened, in orbit around the star Upsilon Andromedae. There, two enormous worlds are inclined at an angle of 30 degrees to each other, compared to the most extreme angle in our Solar System of just seven degrees.

“Knowing that this kind of planetary system existed raised the question of whether a world could be habitable under such conditions,” said Barnes.

John Armstrong of Weber State, lead author on the study, which was published in Astrobiology, said that expanding the habitable zone to include these worlds could double the number of potentially habitable planets in the galaxy.

“The habitable zone could be extended much farther from the star than we normally expect,” he said. “Rather than working against habitability, the rapid changes in the orientation of the planet could turn out be a real boon sometimes.”

First Potentially Habitable Exoplanet Confirmed: It May Have Water:

The first Earth-sized exoplanet orbiting within the habitable zone of another star has been confirmed by observations with both the W. M. Keck Observatory and the Gemini Observatory. The initial discovery, made by NASA’s Kepler Space Telescope, is one of a handful of smaller planets found by Kepler and verified using large ground-based telescopes. It also confirms that Earth-sized planets do exist in the habitable zone of other stars.


"What makes this finding particularly compelling is that this Earth-sized planet, one of five orbiting this star, which is cooler than the Sun, resides in a temperate region where water could exist in liquid form," says Elisa Quintana of the SETI Institute and NASA Ames Research Center who led the paper published in the current issue of the journal Science. The region in which this planet orbits its star is called the habitable zone, as it is thought that life would most likely form on  with liquid water.

Steve Howell, Kepler’s Project Scientist and a co-author on the paper, adds that neither Kepler (nor any telescope) is currently able to directly spot an exoplanet of this size and proximity to its . “However, what we can do is eliminate essentially all other possibilities so that the validity of these planets is really the only viable option.”

With such a small host star, the team employed a technique that eliminated the possibility that either a background star or a stellar companion could be mimicking what Kepler detected. To do this, the team obtained extremely high spatial resolution observations from the eight-meter Gemini North telescope on Mauna Kea in Hawai`i using a technique called speckle imaging, as well as adaptive optics (AO) observations from the ten-meter Keck II telescope, Gemini’s neighbor on Mauna Kea. Together, these data allowed the team to rule out sources close enough to the star’s line-of-sight to confound the Kepler evidence, and conclude that Kepler’s detected signal has to be from a small planet transiting its host star.

First potentially habitable Earth-sized planet confirmed by Gemini and Keck observatories

The diagram compares the planets of the inner solar system to Kepler-186, a five-planet system about 500 light-years from Earth in the constellation Cygnus. The five planets of Kepler-186 orbit a star classified as a M1 dwarf, measuring half …more

"The Keck and Gemini data are two key pieces of this puzzle," says Quintana. "Without these complementary observations we wouldn’t have been able to confirm this Earth-sized planet."

The Gemini “speckle” data directly imaged the system to within about 400 million miles (about 4 AU, approximately equal to the orbit of Jupiter in our solar system) of the host star and confirmed that there were no other stellar size objects orbiting within this radius from the star. Augmenting this, the Keck AO observations probed a larger region around the star but to fainter limits. According to Quintana,

First potentially habitable Earth-sized planet confirmed by Gemini and Keck observatories

The artistic concept of Kepler-186f is the result of scientists and artists collaborating to help imagine the appearance of these distant worlds. Credit: Credit: NASA Ames/SETI Institute/JPL-CalTech.

"These Earth-sized planets are extremely hard to detect and confirm, and now that we’ve found one, we want to search for more. Gemini and Keck will no doubt play a large role in these endeavors."

The host star, Kepler-186, is an M1-type dwarf star relatively close to our solar system, at about 500 light years and is in the constellation of Cygnus. The star is very dim, being over half a million times fainter than the faintest stars we can see with the naked eye. Five small planets have been found orbiting this star, four of which are in very short-period orbits and are very hot. The planet designated Kepler-186f, however, is earth-sized and orbits within the star’s . The Kepler evidence for this planetary system comes from the detection of planetary transits. These transits can be thought of as tiny eclipses of the host star by a planet (or planets) as seen from the Earth. When such planets block part of the star’s light, its total brightness diminishes. Kepler detects that as a variation in the star’s total light output and evidence for planets. So far more than 3,800 possible planets have been detected by this technique with Kepler.

 

This animation depicts Kepler-186f, the first validated Earth-size planet orbiting a distant star in the habitable zone — a range of distances from a star where liquid water might pool on the surface of an orbiting planet. The discovery of …more

The Gemini data utilized the Differential Speckle Survey Instrument (DSSI) on the Gemini North telescope. DSSI is a visiting instrument developed by a team led by Howell who adds, “DSSI on Gemini Rocks! With this combination, we can probe down into this star system to a distance of about 4 times that between the Earth and the Sun. It’s simply remarkable that we can look inside other solar systems.” DSSI works on a principle that utilizes multiple short exposures of an object to capture and remove the noise introduced by atmospheric turbulence producing images with extreme detail.

Observations with the W.M. Keck Observatory used the Natural Guide Star Adaptive Optics system with the NIRC2 camera on the Keck II telescope. NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II  system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space

Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other , and study detailed morphology of distant galaxies.

"The observations from Keck and Gemini, combined with other data and numerical calculations, allowed us to be 99.98% confident that Kepler-186f is real," says Thomas Barclay, a Kepler scientist and also a co-author on the paper. "Kepler started this story, and Gemini and Keck helped close it," adds Barclay.

NASA’s Cassini spacecraft has documented the formation of a small icy object within the rings of Saturn. Informally named “Peggy,” the object may be a new moon. Details of the observations were published online today by the journal Icarus.

"We have not seen anything like this before," said Carl Murray of Queen Mary University of London, and the report’s lead author. "We may be looking at the act of birth, where this object is just leaving the rings and heading off to be a moon in its own right."

Images taken with Cassini’s narrow angle camera on April 15, 2013 show disturbances at the very edge of Saturn’s A ring — the outermost of the planet’s large, bright rings. One of these disturbances is an arc about 20 percent brighter than its surroundings, 750 miles (1,200 kilometers) long and 6 miles (10 kilometers) wide. Scientists also found unusual protuberances in the usually smooth profile at the ring’s edge. Scientists believe the arc and protuberances are caused by the gravitational effects of a nearby object.

The object is not expected to grow any larger, and may even be falling apart. But the process of its formation and outward movement aids in our understanding of how Saturn’s icy moons, including the cloud-wrapped Titan and ocean-holding Enceladus, may have formed in more massive rings long ago. It also provides insight into how Earth and other planets in our solar system may have formed and migrated away from our star, the sun.


Peggy is too small to see in images so far. Scientists estimate it is probably no more than about a half mile in diameter. Saturn’s icy moons range in size depending on their proximity to the planet — the farther from the planet, the larger. And many of Saturn’s moons are comprised primarily of ice, as are the particles that form Saturn’s rings. Based on these facts, and other indicators, researchers recently proposed that the icy moons formed from ring particles and then moved outward, away from the planet, merging with other moons on the way.
"Witnessing the possible birth of a tiny moon is an exciting, unexpected event," said Cassini Project Scientist Linda Spilker, of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. According to Spilker, Cassini’s orbit will move closer to the outer edge of the A ring in late 2016 and provide an opportunity to study Peggy in more detail and perhaps even image it.

"The theory holds that Saturn long ago had a much more massive ring system capable of giving birth to larger moons," Murray said. "As the moons formed near the edge, they depleted the rings."

It is possible the process of moon formation in Saturn’s rings has ended with Peggy, as Saturn’s rings now are, in all likelihood, too depleted to make more moons. Because they may not observe this process again, Murray and his colleagues are wringing from the observations all they can learn.

(Source: science.nasa.gov)

NASA To Conduct Unprecedented Twin Experiment:

Consider a pair of brothers, identical twins.  One gets a job as an astronaut and rockets into space.  The other gets a job as an astronaut, too, but on this occasion he decides to stay home.  After a year in space, the traveling twin returns home and they reunite.

Are the identical twins still … identical?

NASA is about to find out.

In March of 2015, NASA astronaut Scott Kelly will join cosmonaut Mikhail Kornienko on a one-year mission to the International Space Station.  Their lengthy stay aims to explore the effects of long-term space flight on the human body.

The interesting thing about Scott is, he’s a twin.  His brother Mark is also an astronaut, now retired.  While Scott, the test subject, spends one year circling Earth at 17,000 mph, Mark will remain behind as a control.


The experiment harkens back to Einstein’s “Twin Paradox,” a thought experiment in which one twin rockets to the stars at high speed while the other stays home.  According to Einstein’s theory of relativity, the traveling twin should return younger than his brother—strange but true.
"We will be taking samples and making measurements of the twins before, during, and after the one-year mission," says Craig Kundrot of NASA’s Human Research Program at the Johnson Space Center. "For the first time, we’ll be able two individuals who are genetically identical."

NASA’s study won’t test the flow of time. The ISS would have to approach the speed of light for relativistic effects to kick in.  Just about everything else is covered, though.  NASA’s Human Research Program recently announced the selection of 10 research proposals to study the twins’ genetics, biochemistry, vision, cognition and much more.

"Each proposal is fascinating and could be a feature-length story of its own," says Kundrot.


"We already know that the human immune system changes in space.  It’s not as strong as it is on the ground," explains Kundrot. "In one of the experiments, Mark and Scott will be given identical flu vaccines, and we will study how their immune systems react."
Here are a few examples to give the flavor of the research:

Another experiment will look at telomeres—little molecular “caps” on the ends of human DNA. Here on Earth, the loss of telomeres has been linked to aging.  In space, telomere loss could be accelerated by the action of cosmic rays.  Comparing the twins’ telomeres could tell researchers if space radiation is prematurely aging space travelers.

Meanwhile in the gut, says Kundrot, “there is a whole microbiome essential to human digestion.  One of the experiments will study what space travel does to [inner bacteria] which, by the way, outnumber human cells by 10-to-1.”

Other proposals are equally fascinating.  One seeks to discover why astronaut vision changes in space.  “Sometimes, their old glasses from Earth don’t work,” notes Kundrot.  Another will probe a phenomenon called “space fog”—a lack of alertness and slowing of mental gears reported by some astronauts in orbit. 

"These will not be 10 individual studies," says Kundrot. "The real power comes in combining them to form an integrated picture of all levels from biomolecular to psychological.  We’ll be studying the entire astronaut."

Separated for a full year, Scott and Mark will make it possible for future astronauts to travel farther than ever before, and still look forward to happy reunions when they return home.

(Source: science.nasa.gov)

Mars: Osuga Valles

The central portion of Osuga Valles, which has a total length of 164 km. In some places, it is 20 km wide and plunges to a depth of 900 m. It is located approximately 170 km south of Eos Chaos, which is located at the periphery in the far eastern portion of the vast Valles Marineris canyon system. Catastrophic flooding is thought to have created the heavily eroded Osuga Valles, which displays streamlined islands and a grooved floor carved by fast-flowing water. The water flowed in a northeasterly direction (towards the bottom right in this image) and eventually drained into another region of chaotic terrain, just seen at the bottom of the image. Several large impact craters are also seen in this scene, including the ghostly outline of an ancient, partially buried crater in the bottom centre of the image.  The image was created using data acquired with the High Resolution Stereo Camera on Mars Express on 7 December 2013 during orbit 12 624. The image resolution is about 17 m per pixel and the image centre is at about 15ºS / 322ºE. Caption: ESA ESA/DLR/FU Berlin

Saturn and Hexagon

Saturn’s winds race furiously around the planet, blowing at speeds in excess of 600 miles (1,000 kilometers) per hour at the equator. As they do so, they form distinct bands and zones which encircle the planet’s pole, as well as its famous hexagon. These zonal winds spin off swirls and eddies, which are significant storms in their own right. This view looks toward the sunlit side of the rings from about 51 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Dec. 27, 2013 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers.  The view was acquired at a distance of approximately 1.3 million miles (2 million kilometers) from Saturn. Image scale is 75 miles (120 kilometers) per pixel. Caption: Cassini Solstice Team NASA/JPL-Caltech/Space Science Institute

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