Close Mars - Astronomy picture of the day - 2018 August 31

Close Mars 
Image Credit & Copyright: D. Peach, V. Suc, Chilescope team

Explanation: Still bright in evening skies, Mars was just past opposition and closest to Earth on July 31, a mere 57.6 million kilometers away. Captured only a week later, this remarkable image shows the Red Planet's disk near its maximum size in earthbound telescopes, but still less than 1/74th the apparent diameter of a Full Moon. Broad regional surface shadings are starting to reappear in the tantalizing view as the latest planet-wide dust storm subsides. With the bright south polar cap at the bottom, the Valles Marineris extends along the center of the disk. Just below it lies the roughly circular Solis Lacus region sometimes known as the Eye of Mars. In a line, three prominent dark spots left of center are the volcanic Tharsis Montes.

The NGC 6914 Complex - Astronomy picture of the day - 2018 August 30

The NGC 6914 Complex 
Image Credit & Copyright: Ivan Eder

Explanation: A study in contrasts, this colorful skyscape features stars, dust, and glowing gas in the vicinity of NGC 6914. The complex of reflection nebulae lies some 6,000 light-years away, toward the high-flying northern constellation Cygnus and the plane of our Milky Way Galaxy. Obscuring interstellar dust clouds appear in silhouette while reddish hydrogen emission nebulae, along with the dusty blue reflection nebulae, fill the cosmic canvas. Ultraviolet radiation from the massive, hot, young stars of the extensive Cygnus OB2 association ionize the region's atomic hydrogen gas, producing the characteristic red glow as protons and electrons recombine. Embedded Cygnus OB2 stars also provide the blue starlight strongly reflected by the dust clouds. The nearly 1 degree wide telescopic field of view spans about 100 light-years at the estimated distance of NGC 6914.

Nearby Cepheid Variable RS Pup - Astronomy picture of the day - 2018 August 29

Nearby Cepheid Variable RS Pup 
Image Credit: NASA, ESA, Hubble Heritage Team; Acknowledgement: Howard Bond (STScI & Penn State U.)

Explanation: In the center is one of the most important stars on the sky. This is partly because, by coincidence, it is surrounded by a dazzling reflection nebula. Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous. In fact, RS Pup is a Cepheid type variable star, a class of stars whose brightness is used to estimate distances to nearby galaxies as one of the first steps in establishing the cosmic distance scale. As RS Pup pulsates over a period of about 40 days, its regular changes in brightness are also seen along the nebula delayed in time, effectively a light echo. Using measurements of the time delay and angular size of the nebula, the known speed of light allows astronomers to geometrically determine the distance to RS Pup to be 6,500 light-years, with a remarkably small error of plus or minus 90 light-years. An impressive achievement for stellar astronomy, the echo-measured distance also more accurately establishes the true brightness of RS Pup, and by extension other Cepheid stars, improving the knowledge of distances to galaxies beyond the Milky Way. The featured image was taken by the Hubble Space Telescope.

Sea and Sky Glows over the Oregon Coast - Astronomy picture of the day - 2018 August 28

Sea and Sky Glows over the Oregon Coast 
Image Credit & Copyright: Rudy Montoya

Explanation: Every step caused the sand to light up blue. That glow was bioluminescence -- a blue radiance that also lights the surf in this surreal scene captured last month at Meyer's Creek Beach in Oregon, USA. Volcanic stacksdot the foreground sea, while a thin fog layer scatters light on the horizon. The rays of light spreading from the left horizon were created by car headlights on the Oregon Coast Highway (US 101), while the orange light on the right horizon emanates from a fishing boat. Visible far in the distance is the band of our Milky Way Galaxy, appearing to rise from a dark rocky outcrop. Sixteen images were added together to bring up the background Milky Way and toreduce noise.

Total Solar Eclipse Shadow from a Balloon - Astronomy picture of the day - 2018 August 27

Total Solar Eclipse Shadow from a Balloon 
Image Credit: Kuaray Project, NASA Eclipse Ballooning Project, Brasilia Astronomy Club, Montana State U.

Explanation: Where were you during the Great American Eclipse of 2017? A year ago last week, over 100 million of people in North America went outside to see a partial eclipse of the Sun, while over ten million drove across part of the USA to see the Sun completely disappear behind the Moon -- a total solar eclipse. An estimated 88 percent of American adults saw the eclipse either personally or electronically. One of the better photographed events in human history, images from the eclipse included some unusual vistas, such as from balloons floating in the Earth's stratosphere. About fifty such robotic balloons were launched as part of NASA's Eclipse Ballooning project. Featured is a frame taken from a 360-degree panoramic video captured by one such balloon set aloft in Idaho by students from Brazil in conjunction with NASA and Montana State University. Pictured, the dark shadow of the Moon was seen crossingthe Earth below. Although the total eclipse lasted less than three minutes, many who saw it may remember it for a lifetime. Many North Americans will get a another chance to experience a total solar eclipse in 2024.

Fire on Earth - Astronomy picture of the day - 2018 August 26

Fire on Earth 
Image Credit: John McColgan (AFS, BLM)

Explanation: Sometimes, regions of planet Earth light up with fire. Since fire is the rapid acquisition of oxygen, and since oxygen is a key indicator of life, fire on any planet would be an indicator of life on that planet. Most of the Earth's land has been scorched by fire at some time in the past. Although causing many a tragedy, for many places on Earth fire is considered part of a natural ecosystem cycle. Large forest fires on Earth are usually caused either by humans orlightning and can be visible from orbit. Featured from the year 2000, stunned elk avoid a fire sweeping through Montana's Bitterroot Valley by standing in a river.

Tchaikovsky - "Immagini autunnali" - Slides - Musica

"Immagini autunnali"

Stripping ESO 137-001 - Astronomy picture of the day - 2018 August 25

Stripping ESO 137-001 
Image Credit: NASA, ESA, CXC

Explanation: Spiral galaxy ESO 137-001 hurtles through massive galaxy cluster Abell 3627 some 220 million light years away. The distant galaxy is seen in this colorful Hubble/Chandra composite image through a foreground of the Milky Way's stars toward the southern constellation Triangulum Australe. As the spiral speeds along at nearly 7 million kilometers per hour, its gas and dust are stripped away when ram pressure with the cluster's own hot, tenuous intracluster medium overcomes the galaxy's gravity. Evident in Hubble's near visible light data, bright star clusters have formed in the stripped material along the short, trailing blue streaks. Chandra's X-ray data shows off the enormous extent of the heated, stripped gas as diffuse, darker blue trails stretching over 400,000 light-years toward the bottom right. The significant loss of dust and gas will make new star formation difficult for this galaxy. A yellowish elliptical galaxy, lacking in star forming dust and gas, is just to the right of ESO 137-001 in the frame.

Messier 20 and 21 - Astronomy picture of the day - 2018 August 24

Messier 20 and 21 
Image Credit & Copyright: Ignacio Diaz Bobillo

Explanation: The beautiful Trifid Nebula, also known as Messier 20, is easy to find with a small telescope in the nebula rich constellation Sagittarius. About 5,000 light-years away, the colorful study in cosmic contrasts shares this well-composed, nearly 1 degree wide field with open star cluster Messier 21 (bottom right). Trisected by dust lanes the Trifid itself is about 40 light-years across and a mere 300,000 years old. That makes it one of the youngest star forming regions in our sky, with newborn and embryonic stars embedded in its natal dust and gas clouds. Estimates of the distance to open star cluster M21 are similar to M20's, but though they share this gorgeous telescopic skyscape there is no apparent connection between the two. In fact, M21's stars are much older, about 8 million years old.

Comet, Heart and Soul - Astronomy picture of the day - 2018 August 23

Comet, Heart and Soul
Image Credit & Copyright: Juan Carlos Casado (TWAN, Earth and Stars)

Explanation: The greenish coma of comet 21P/Giacobini-Zinner stands out at the left of this telephoto skyscape spanning over 10 degrees toward the northern constellations Cassiopeia and Perseus. Captured on August 17, the periodic comet is the known parent body of the upcoming Draconid meteor shower. Predicted to be at its brightest next month, the comet is actually in the foreground of the rich starfield, only about 4 light-minutes from our fair planet. Giacobini-Zinner should remain too faint for your eye to see though, like the colorful Heart and Soul nebulae near the center of the sensitive digital camera's field of view. But the pair of open star clusters at the right, h and Chi Persei, could just be seen by the unaided eye from dark locations. The Heart and Soul nebulae with their own embedded clusters of young stars a million or so years old, are each over 200 light-years across and 6 to 7 thousand light-years away. They are part of a large, active star forming complex sprawling along the Perseus spiral arm of our Milky Way Galaxy. Also known as the Double Cluster, h and Chi Persei are located at about that same distance. Periodic Giacobini-Zinner was visited by a spacecraft from Earth when the repurposed International Cometary Explorer passed through its tail in September 1985.

Asteroid Ryugu from Hayabusa2 - Astronomy picture of the day - 2018 August 22

Asteroid Ryugu from Hayabusa2 
Image Credit & Copyright: ISAS, JAXA,

Explanation: This big space diamond has an estimated value of over 80 billion dollars. It's only diamond in shape, though -- asteroid 162173 Ryugu is thought to be composed of mostly nickel and iron. Asteroids like Ryugu are interesting for several reasons, perhaps foremost because they are near the Earth and might, one day in the far future, pose an impact threat. In the nearer term, Ryugu is interesting because it may be possible to send future spacecraft there to mine it, thus providing humanity with a new source of valuable metals. Scientifically, Ryugu is interesting because it carries information about how our Solar System formed billions of years ago, and why its orbit takes it so closeto Earth. Japan's robotic spacecraft Hayabusa2 just arrived at this one-kilometer wide asteroid in late June. The featured image shows surface structures unknown before spacecraft Hayabusa2's arrival, including rock fields and craters. Within the next three months, Hayabusa2 is scheduled to unleash several probes, some that will land on Ryugu and hop around, while Hayabusa2 itself will mine just a little bit of the asteroid for return to Earth.

Glowing Elements in the Soul Nebula - Astronomy picture of the day - 2018 August 21

Glowing Elements in the Soul Nebula 
Image Credit & Copyright: Jesús M.Vargas & Maritxu Poyal

Explanation: Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula (IC 1898) can be found in the direction of the constellation Cassiopeia, who Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. The Soul Nebula houses several open clusters of stars, a large radio source known as W5, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light years and is usually imaged next to its celestial neighbor the Heart Nebula (IC 1805). The featured image is a composite of three exposures in different colors: red as emitted by hydrogen gas, yellow as emitted by sulfur, and blue as emitted by oxygen.

Active Prominences on a Quiet Sun - Astronomy picture of the day - 2018 August 20

Active Prominences on a Quiet Sun  Image Credit & Copyright: Alan Friedman (Averted Imagination)

Explanation: Why is the Sun so quiet? As the Sun enters into a period of time known as a Solar Minimum, it is, as expected, showing fewer sunspots and active regions than usual. The quietness is somewhat unsettling, though, as so far this year, most days show no sunspots at all. In contrast, from 2011 - 2015, during Solar Maximum, the Sun displayed spots just about every day. Maxima and minima occur on an 11-year cycle, with the last Solar Minimum being the most quiet in a century. Will this current Solar Minimum go even deeper? Even though the Sun's activity affects the Earth and its surroundings, no one knows for sure what the Sun will do next, and the physics behind the processes remain an active topic of research. The featured image was taken three weeks ago and shows that our Sun is busy even on a quiet day. Prominences of hot plasma, some larger than the Earth, dance continually and are most easily visible over the edge.

Asperitas Clouds Over New Zealand - Astronomy picture of the day - 2018 August 19

Asperitas Clouds Over New Zealand 
Image Credit & Copyright: Witta Priester

Explanation: What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Formally recognized as a distinct cloud type only last year, Asperitas clouds can be stunning in appearance, unusual in occurrence, and are relatively unstudied. Whereas most low cloud decks are flat bottomed, asperitas clouds appear to have significant vertical structure underneath. Speculation therefore holds that asperitas clouds might be related to lenticular clouds that form near mountains, or mammatus clouds associated with thunderstorms, or perhaps a foehn wind -- a type of dry downward wind that flows off mountains. Such a wind called the Canterbury arch streams toward the east coast of New Zealand's South Island. The featured image, taken above Hanmer Springs in Canterbury, New Zealand, in 2005, shows great detail partly because sunlight illuminates the undulating clouds from the side.

Seeing Titan - Astronomy picture of the day - 2018 August 18

Seeing Titan 
Image Credit: VIMS Team, U. Arizona, ESA, NASA

Explanation: Shrouded in a thick atmosphere, Saturn's largest moon Titan really is hard to see. Small particles suspended in the upper atmosphere cause an almost impenetrable haze, strongly scattering light at visible wavelengths and hiding Titan's surface features from prying eyes. But Titan's surface is better imaged at infrared wavelengths where scattering is weaker and atmospheric absorption is reduced. Arrayed around this centered visible light image of Titan are some of the clearest global infrared views of the tantalizing moon so far. In false color, the six panels present a consistent processing of 13 years of infrared image data from the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft. They offer a stunning comparison with Cassini's visible light view.

Une réussite : Le traitement extracorporel du cancer - Médecine

Une équipe italienne a traité un patient atteint d'un cancer du foie très avancé grâce à une méthode inédite. Les chercheurs ont retiré l'organe, l'ont traité par irradiation avant de le réimplanter. Plusieurs mois après l'opération, l'homme qu'on disait condamné va bien. Cette technique pourra-t-elle demain être étendue à tous les organes transplantables : reins, poumons, pancréas… ?

Pour la première fois au monde, un cancer a été traité en retirant l'organe du corps, en lui administrant un traitement par radiothérapie et en le réimplantant. Cette opération extracorporelle a permis aux médecins d'administrer de fortes doses de radiations aux différentes tumeurs disséminées sur le foie, sans affecter les organes environnants.

Un cas "désespéré"

Agé de 48 ans, le patient était jugé comme étant dans une situation désespérée. Suite au diagnostic d'un cancer du colon, une partie de l'intestin lui avait été enlevé en 2000. Mais le cancer avait eu le temps d'atteindre un autre organe : le foie. Des scanners révélèrent pas moins de 14 tumeurs sur l'organe et, suite à l'opération, de nombreuses autres furent identifiées. De tels cancers sont généralement très difficiles à traiter par les moyens thérapeutiques conventionnels. Le pronostic avancé ne dépassait pas trois à quatre mois d'espérance de vie…

Un an après l'opération qui a duré 21 heures, l'homme est en bonne santé.
Cette nouvelle technique baptisée TAORMINA devrait bientôt concerner d'autres patients.

"Enthousiaste au vu des premiers résultats, le Dr Pirelli déclare dès maintenant que ce type d'opération permet le traitement intégral de l'organe malade et peut être étendu à tous les organes transplantables : reins, pancréas, poumons…".

Doctissimo

Perseid Fireball and Persistent Train - Astronomy picture of the day - 2018 August 17

Perseid Fireball and Persistent Train 
Image Credit & Copyright: Petr Horálek

Explanation: Before local midnight on August 12, this brilliant Perseid meteor flashed above the Poloniny Dark Sky Park, Slovakia, planet Earth. Streaking beside the summer Milky Way, its initial color is likely due to the shower meteor's characteristically high speed. Moving at about 60 kilometers per second, Perseid meteors can excite green emission from oxygen atoms while passing through the thin atmosphere at high altitudes. Also characteristic of bright meteors, this Perseid left a lingering visible trail known as a persistent train, wafting in the upper atmosphere. Its development is followed in the inset frames, exposures separated by one minute and shown at the scale of the original image. Compared to the brief flash of the meteor, the wraith-like trail really is persistent. After an hour faint remnants of this one could still be traced, expanding to over 80 degrees on the sky.

Parker vs Perseid - Astronomy picture of the day - 2018 August 16

Parker vs Perseid 
Image Credit & Copyright: Derek Demeter (Emil Buehler Planetarium)

Explanation: The brief flash of a bright Perseid meteor streaks across the upper right in this composited series of exposures made early Sunday morning near the peak of the annual Perseid meteor shower. Set up about two miles from Space Launch Complex 37 at Cape Canaveral Air Force Station, the photographer also captured the four minute long trail of a Delta IV Heavy rocket carrying the Parker Solar Probe into the dark morning sky. Perseid meteors aren't slow. The grains of dust from periodic comet Swift-Tuttle vaporize as they plow through Earth's upper atmosphere at about 60 kilometers per second (133,000 mph). On its way to seven gravity-assist flybys of Venus over its seven year mission, the Parker Solar Probe's closest approach to the Sun will steadily decrease, finally reaching a distance of 6.1 million kilometers (3.8 million miles). That's about 1/8 the distance between Mercury and the Sun, and within the solar corona, the Sun's tenuous outer atmosphere. By then it will be traveling roughly 190 kilometers per second (430,000 mph) with respect to the Sun, a record for fastest spacecraft from planet Earth.

Launch of the Parker Solar Probe - Astronomy picture of the day - 2018 August 15

Launch of the Parker Solar Probe 
Image Credit & Copyright: John Kraus

Explanation: When is the best time to launch a probe to the Sun? The now historic answer -- which is not a joke because this really happened this past weekend -- was at night. Night, not only because NASA's Parker Solar Probe's (PSP) launch window to its planned orbit occurred, in part, at night, but also because most PSP instruments will operate in the shadow of its shield -- in effect creating its own perpetual night near the Sun. Before then, years will pass asthe PSP sheds enough orbital energy to approach the Sun, swinging past Venus seven times. Eventually, the PSP is scheduled to pass dangerously close to the Sun, within 9 solar radii, the closest ever. This close, the temperature will be 1,400 degrees Celsius on the day side of the PSP's Sun shield -- hot enough to melt many forms of glass. On the night side, though, it will be near room temperature. A major goal of the PSP's mission to the Sun is to increase humanity's understanding of the Sun's explosions that impact Earth's satellites and power grids. Pictured is the night launch of the PSP aboard the United Launch Alliances' Delta IV Heavy rocket early Sunday morning.

M86 in the Central Virgo Cluster - Astronomy picture of the day - 2018 August 14

M86 in the Central Virgo Cluster 
Image Credit & Copyright: Mark Hanson, Stan Watson Obs.

Explanation: Is there a bridge of gas connecting these two great galaxies? Quite possibly, but it is hard to be sure. M86 on the upper left is a giant elliptical galaxy near the center of the nearby Virgo Cluster of galaxies. Our Milky Way Galaxy is falling toward the Virgo Cluster, located about 50 million light years away. To the lower right of M86 is unusual spiral galaxy NGC 4438, which, together with angular neighbor NGC 4435, are known as the Eyes Galaxies(also Arp 120). Featured here is one of the deeper images yet taken of the region, indicating that red-glowing gas surrounds M86 and seemingly connects it to NGC 4438. The image spans about the size of the full moon. It is also known, however, that cirrus gas in our own Galaxy is superposed in front of the Virgo cluster, and observations of the low speed of this gas seem more consistent with this Milky Way origin hypothesis. A definitive answer may come from future research, which may also resolve how the extended blue arms of NGC 4435 were created.

Les dents d’un ancien requin gigantesque retrouvées en Australie - Paléontologie

Philip Mullaly se promenait sur la célèbre Great Ocean Road (Victoria), une zone réputée pour ses fossiles que vous retrouverez à environ 100 kilomètres de Melbourne, lorsqu’il fit la découverte. « Je marchais le long de la plage à la recherche de fossiles, je me suis retourné et j’ai vu une étincelle dans un rocher, puis j’ai vu un quart de la dent exposée, a-t-il raconté à l’AFP. J’ai été tout de suite enthousiaste, c’était simplement parfait, et je savais qu’il s’agissait d’une importante découverte qu’il fallait partager ».

« Ces dents ont une portée internationale, puisque c’est l’une des trois séries de dents de Carcharodon angustidens dans le monde, et c’est la première série découverte en Australie », explique le paléontologiste Erich Fitzgerald. Quasiment toutes les dents de requins retrouvées sont uniques, et il est en effet extrêmement rare de trouver plusieurs dents associées provenant du même requin.

Deux expéditions ont par la suite été menées pour creuser le site plus en profondeur. Plus d’une quarantaine de dents ont au final été découvertes. La plupart provenaient du méga-requin, mais plusieurs dents plus petites appartenaient également au requin à six dents (Hexanchus), un charognard qui évolue encore aujourd’hui. Pour Tim Ziegler (lui aussi paléontologiste) plusieurs petits requins se seraient alors acharnés sur la carcasse du plus gros, et quelques dents se seraient alors délogées au passage.

Science Post

Sur Mars, suivez le passage de la Terre ! - Espace

Cet été, la rédaction du magazine « Ciel & Espace » s’est délocalisée sur la planète rouge. Depuis la surface de Mars, l’observation du ciel profond ne change pas vraiment. Ce sont le ballet des satellites et le spectacle des planètes qui surprendront l’astronome amateur terrien.

En ce 10 novembre 2084, les occupants de la première base martienne s’apprêtent à suivre un phénomène inédit : le passage de la Terre devant le Soleil ! Un événement rarissime sur Mars : le précédent a eu lieu tout juste un siècle plus tôt, en 1984. Et pour le suivant, il faudra revenir en 2163 ! De leur position, par 25° de latitude nord entre Syrtis Major et Elysium Mons, les astronautes sont aux premières loges. Le passage de la planète bleue devant l’astre du jour offre une occasion en or de vérifier si nous sommes capables de détecter la vie sur Terre…/...

Ciel & Espace

The Pencil Nebula in Red and Blue - Astronomy picture of the day - 2018 August 13

The Pencil Nebula in Red and Blue 
Image Credit & Copyright: José Joaquín Perez

Explanation: This shock wave plows through interstellar space at over 500,000 kilometers per hour. Near the top and moving up in this sharply detailed color composite, thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on. Cataloged as NGC 2736, its elongated appearance suggests its popular name, the Pencil Nebula. The Pencil Nebula is about 5 light-years long and 800 light-years away, but represents only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter, the expanding debris cloud of a star that was seen to explode about 11,000 years ago. Initially, the shock wavewas moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the featured narrow-band, wide field image, red and blue colors track the characteristic glow of ionized hydrogen and oxygen atoms, respectively.

Meteor before Galaxy - Astronomy picture of the day - 2018 August 12

Meteor before Galaxy 
Image Credit & Copyright: Fritz Helmut Hemmerich

Explanation: What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a sand-sized rock from deep space crossed right in front of our Milky Way Galaxy's far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field. The meteor flared several times while braking violently upon entering Earth's atmosphere. The green color was created, at least in part, by the meteor's gas glowing as it vaporized. Although the exposure was timed to catch a Perseids meteor, the orientation of the imaged streak seems a better match to a meteor from the Southern Delta Aquariids, a meteor shower that peaked a few weeks earlier. Not coincidentally, the Perseid Meteor Shower peaks again tonight.

Moon, Mars, and Milky Way - Astronomy picture of the day - 2018 August 11

Moon, Mars, and Milky Way 
Image Credit & Copyright: Taha Ghouchkanlu (TWAN)

Explanation: Just two weeks ago, dark skies over the desert in northern Iran held this alluring celestial vista. The dramatic digital mosaic finds the Moon and Mars alongside the Milky Way's dusty rifts, stars, and nebulae. Captured through a series of exposures to cover a range in brightness, that night's otherwise Full Moon is immersed in Earth's shadow. It actually appears fainter and redder than the Red Planet itself during the widely watched total lunar eclipse.For cosmic tourists, the skyscape also includes the Lagoon (M8) and Trifid (M20) nebulae and planet Saturn shining against the Milky Way's pale starlight. The Moon isn't quite done with its shadow play, though. Today, the New Moon partially eclipses the Sun for much of northern planet Earth.

Spiral Galaxy NGC 6744 -Astronomy picture of the day - 2018 August 10

Spiral Galaxy NGC 6744 
Image Credit & Copyright: Martin Pugh

Explanation: Beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo and appears as only a faint, extended object in small telescopes. We see the disk of the nearby island universe tilted towards our line of sight. This remarkably detailed galaxy portrait covers an area about the angular size of the full moon. In it, the giant galaxy's elongated yellowish core is dominated by the light from old, cool stars. Beyond the core, grand spiral arms are filled with young blue star clusters and speckled with pinkish star forming regions. An extended arm sweeps past a smaller satellite galaxy at the upper left. NGC 6744's galactic companion is reminiscent of the Milky Way's satellite galaxy the Large Magellanic Cloud.

Red Planet, Red Moon, and Mars - Astronomy picture of the day - 2018 August 9

Red Planet, Red Moon, and Mars 
Image Credit & Copyright: Alex Cherney (Terrastro, TWAN)

Explanation: Mars is also known as The Red Planet, often seen with a reddish tinge in dark night skies. Mars shines brightly at the upper left of this gorgeous morning twilight view from Mornington Peninsula, Victoria, Australia, but the Moon and planet Earth look redder still. Taken on July 27, the totally eclipsed Moon is setting. It looks reddened because the Earth's umbral shadow isn't completely dark. Instead Earth's shadow is suffused with a faint red light from all the planet's sunsets and sunrises seen from the perspective of an eclipsed Moon. The sunsets and sunrises are reddened because Earth's atmosphere scatters blue light more strongly than red, creating the faint bluish twilight sky. Of course, craggy seaside rocks also take on the reddened colors of this Australian sunrise.

Os Paises que mais seguiram este blogue desde o inicio - Estatisticas

U.S.A. - 2125

FRANCE - 1278

BRASIL - 452

ALEMANHA - 452

BELGICA - 358

CANADA - 332

EMIRADOS ARABES UNIDOS - 288

PORTUGAL - 221

PERU - 174

UCRÂNIA - 60

Eclipsed Moon and Mars over Mountains - Astronomy picture of the day - 2018 August 7

Eclipsed Moon and Mars over Mountains 
Image Credit & Copyright: Clément Brustel

Explanation: There is something unusual about this astronomically-oriented photograph. It's not obvious -- it was discovered only during post-processing. It is not the Moon, although capturing the Moon rising during a total lunar eclipse is quite an unusually interesting sight. (Other interesting images also captured during last month's eclipse can be found here.) It is not Mars, found to the lower right of the Moon, although Mars being captured near its brightest also makes for an unusually interesting sight. (Mars is visible nearly the entire night this month; other interesting images of it can be found here.) It is not the foreground mountains, although the French Alps do provide unusually spectacular perspectives on planet Earth. (Other interesting mountainous starscapes can be found here.) It is the goat.

Claude Debussy - "Rêverie" - Diapos - Musique

"Rêverie"

Live: Cosmic Rays from Minnesota - Astronomy picture of the day - 2018 August 6

Live: Cosmic Rays from Minnesota 
Image Credit: Fermilab, NuMI, NOvA Collaboration

Explanation: Cosmic rays from outer space go through your body every second. Typically, they do you no harm. The featured image shows some of these fast moving particles as streaks going through Fermilab's NOvA Far Detectorlocated in Ash River, Minnesota, USA. Although the image updates every 15 seconds, it only shows cosmic rays that occurred over a (changing) small fraction of that time, and mostly shows only one type of particle: muons. TheNOvA Far Detector's main purpose is not to detect cosmic rays, though, but rather neutrinos from the NuMI beam shot through the Earth from Fermilab near Chicago, Illinois, USA, 810 kilometers away. Only a few neutrino events are expected in NOvA per week, though. The NuMI / NOvA experiment is allowing humanity to better explore the nature of neutrinos, for example how frequently they change type during their trip. Cosmic rays themselves werediscovered only about 100 years ago and can not only alter computer memory, but may have helped to create DNA mutations that resulted in, eventually, humans.

Carro movido a água salgada fez 150 mil quilómetros sem poluição - Artigo

A ideia de usar água como combustível é antiga, mas não é fácil de transportar para a prática. Neste momento, apenas um construtor está a testar um carro do género, a nanoFlowcell, uma marca experimental que acabou de completar 150 mil quilómetros em testes de estrada com o seu modelo mais recente, o citadino Quantino.

O sistema da nanoFlowcell funciona como uma célula de combustível, mas usa água salgada ionizada em vez de hidrogénio. Neste caso, o líquido com iões positivos fica separado do líquido com iões negativos. Quando ambos passam por uma membrana, os iões interagem, gerando energia elétrica que é usada para mover o automóvel. O resultado final é água, tal como numa célula de combustível de hidrogénio, permitindo ao automóvel funcionar com emissões zero e reabastecimento rápido.

Desde 2014 que a empresa alemã tem vindo a desenvolver protótipos, como o desportivo e-Sportlimousine, o crossover Quant F e o compacto Quantino. Estes têm sido testados em estrada, com o Quantino a mostrar a validade do conceito. Depois de ter completado 100 mil quilómetros em agosto do ano passado, o carro alemão atingiu agora os 150 mil quilómetros em meio ao tráfego. Durante os testes, conseguiu percorrer 1000 quilómetros durante 8 horas e 21 minutos, sem necessitar de reabastecimento.

Tuga Press

Trapezium: At the Heart of Orion - Astronomy picture of the day - 2018 August 5

Trapezium: At the Heart of Orion 
Image Credit: Data: Hubble Legacy Archive, Processing: Robert Gendler

Explanation: Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta-1 Orionis C powers the complex star forming region's entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a recent dynamical study indicates that runaway stellar collisions at an earlier age may have formed a black hole with more than 100 times the mass of the Sun. The presence of a black hole within the cluster could explain the observed high velocities of the Trapezium stars. The Orion Nebula's distance of some 1,500 light-years would make it the closest known black hole to planet Earth.

Central Cygnus Skyscape - Astronomy picture of the day - 2018 August 4

Central Cygnus Skyscape 
Image Credit & Copyright: Mauro Narduzzi (acquisition) / Roberto Colombari (processing)

Explanation: Supergiant star Gamma Cygni lies at the center of the Northern Cross, famous asterism in the constellation Cygnus the Swan. Known by its proper name, Sadr, the bright star also lies at the center of this gorgeous skyscape, featuring a complex of stars, dust clouds, and glowing nebulae along the plane of our Milky Way galaxy. The field of view spans almost 4 degrees (eight Full Moons) on the sky and includes emission nebula IC 1318 and open star cluster NGC 6910. Left of Gamma Cygni and shaped like two glowing cosmic wings divided by a long dark dust lane, IC 1318's popular name is understandably the Butterfly Nebula. Above and left of Gamma Cygni, are the young, still tightly grouped stars of NGC 6910. Some distance estimates for Gamma Cygni place it at around 1,800 light-years while estimates for IC 1318 and NGC 6910 range from 2,000 to 5,000 light-years.

Por que sonhamos? - Artigo

Sonhar é uma das coisas mais estranhas que acontece com os seres humanos. 

Pesquisas recentes conseguiram evidênciar sobre o que é sonhar.

A hipótese de que o sonho está ligado à vida em vigília foi sugerida por Sigmund Freud no início do século 20.

Deve-se ter em mente que sonhos são de dificil interpretação, uma vez que acontecem inteiramente na cabeça de uma pessoa e no momento em que ela não consegue comunicar com outros.

Para estudar o assunto, uma equipa de pesquisadores do Laboratório do Sono da Universidade de Swansea, no Reino Unido, recrutou 20 estudantes voluntários que passaram  muitas noites no Laboratório do Sono, onde permaneceram monitorados por métodos de eletroencefalogramas não invasivos.

Desta forma, os cientistas foram capazes de observar e registar a atividade das ondas cerebrais associadas ao sono, concluindo que sonhos com maior impacto emocional eram mais prováveis de serem incorporados ao sono do que sonhos tediosos e inebriantes.

Jornal Ciência

Central Lunar Eclipse - Astronomy picture of the day - 2018 August 3

Central Lunar Eclipse 
Image Credit & Copyright: Anthony Ayiomamitis (TWAN)

Explanation: Reddened by scattered sunlight, the Moon in the center is passing through the center of Earth's dark umbral shadow in this July 27 lunar eclipse sequence. Left to right the three images are from the start, maximum, and end to 103 minutes of totality from the longest lunar eclipse of the 21st century. The longest path the Moon can follow through Earth's shadow does cross the shadow's center, that's what makes such central lunar eclipses long ones. But July 27 was also the date of lunar apogee, and at the most distant part of its elliptical orbit the Moon moves slowest. For the previous lunar eclipse, last January 31, the Moon was near its orbital perigee. Passing just south of the Earth shadow central axis, totality lasted only 76 minutes. Coming up on January 21, 2019, a third consecutive total lunar eclipse will also be off center and find the Moon near perigee. Then totality will be a mere 62 minutes long.

Eclipse over the Gulf of Poets - Astronomy picture of the day - 2018 August 2

Eclipse over the Gulf of Poets 
Image Credit & Copyright: Paolo Lazzarotti

Explanation: The total phase of the July 27 lunar eclipse lasted for an impressive 103 minutes. That makes it the longest total lunar eclipse of the 21st century. The Moon passed through the center of Earth's shadow while the Moon was near apogee, the most distant point in its elliptical orbit. From start to finish, the entire duration of totality is covered in this composite view. A dreamlike scene, it includes a sequence of digital camera exposures made every three minutes. The exposures track the totally eclipsed lunar disk, accompanied on that night by bright planet Mars, as it climbs above the seaside village of Tellaro, Italy. In the foreground lies the calm mediteranean Gulf of La Spezia, known to some as the Gulf of Poets. In the 3rd century BCE, heliocentric astronomer Aristarchus also tracked the duration of lunar eclipses, though without the benefit of digital clocks and cameras. Using geometry he devised a way to calculate the Moon's distance from the eclipse duration, in terms of the radius of planet Earth.

Astronomy picture of the day - 2018 August 1 - The Iris Nebula in a Field of Dust

The Iris Nebula in a Field of Dust 
Image Credit & Copyright: Franco Sgueglia & Francesco Sferlazza

Explanation: What blue flower grows in this field of dark interstellar dust? The Iris Nebula. The striking blue color of the Iris Nebula is created by light from the bright star SAO 19158 reflecting off of a dense patch of normally dark dust. Not only is the star itself mostly blue, but blue light from the star is preferentially reflected by the dust -- the same affect that makes Earth's sky blue. The brown tint of the pervasive dust comes partly from photoluminescence -- dust converting ultraviolet radiation to red light. Cataloged as NGC 7023, the Iris Nebula is studied frequently because of the unusual prevalence there of Polycyclic Aromatic Hydrocarbons (PAHs), complex molecules that are also released on Earth during the incomplete combustion of wood fires. The bright blue portion of the Iris Nebula spans about six light years. The Iris Nebula, pictured here, lies about 1300 light years distant and can be found with a small telescope toward the constellation of Cepheus.