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segunda-feira, 31 de julho de 2017

Astronomy picture of the day - 2017 July 31

Pluto Flyover from New Horizons 
Credit: NASAJHUAPLSwRI, P. Schenk & J. Blackwell (LPI); Music Open Sea Morning by Puddle of Infinity
Explanation: What if you could fly over Pluto -- what might you see? The New Horizons spacecraft did just this in 2015 July as it shot past the distant world at a speed of about 80,000 kilometers per hour. Recently, many images from this spectacular passage have been color enhanced and digitally combined into the featured two-minute time-lapse video. As your journey begins, light dawns on mountains thought to be composed of water ice but colored by frozen nitrogen. Soon, to your right, you see a flat sea of mostly solid nitrogen that has segmented into strange polygons that are thought to have bubbled up from a comparatively warm interior. Craters and ice mountains arecommon sights below. The video dims and ends over terrain dubbed bladed because it shows 500-meter high ridges separated by kilometer-sized gaps. Although the robotic New Horizons spacecraft has too much momentum ever to return to Pluto, it has now been targeted at Kuiper Belt object 2014 MU 69, which it should shoot past on New Year's Day 2019.

domingo, 30 de julho de 2017

Astronomy picture of the day - 2017 July 30 - A Total Eclipse at the End of the World

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A Total Eclipse at the End of the World 
Image Credit & Copyright: Fred Bruenjes (moonglow.net)
Explanation: Would you go to the end of the world to see a total eclipse of the Sun? If you did, would you be surprised to find someone else there already? In 2003, the Sun, the Moon, Antarctica, and two photographers all lined up in Antarctica during an unusual total solar eclipse. Even given the extreme location, a group of enthusiastic eclipse chasers ventured near the bottom of the world to experience the surreal momentary disappearance of the Sun behind the Moon. One of the treasures collected was the featured picture -- a composite of four separate images digitally combined to realistically simulate how the adaptive human eye saw the eclipse. As the image was taken, both the Moon and the Sun peeked together over an Antarctic ridge. In the sudden darkness, the magnificent corona of the Sun became visible around the Moon. Quite by accident, another photographer was caught in one of the images checking his video camera. Visible to his left are an equipment bag and a collapsible chair. A more easily visible solar eclipse will occur in about three weeks and be visible from the USA.

quinta-feira, 27 de julho de 2017

Astronomy picture of the day - 2017 July 27 - A Sagittarius Triplet

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A Sagittarius Triplet 
Image Credit & Copyright: Josep Drudis
Explanation: These three bright nebulae are often featured on telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula above and left of center, and colorful M20 near the bottom of the frame. The third emission region includes NGC 6559, right of M8 and separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. Over a hundred light-years across the expansive M8 is also known as the Lagoon Nebula. M20's popular moniker is the Trifid. Glowing hydrogen gas creates the dominant red color of the emission nebulae. In striking contrast, blue hues in the Trifid are due to dust reflected starlightThe colorful composite skyscape was recorded with two different telescopes to capture a widefield image of the area and individual close-ups at higher resolution.

quarta-feira, 26 de julho de 2017

Astronomy picture of the day - 2017 July 26 - The Milky Way over Monument Valley

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The Milky Way over Monument Valley 
Image Credit & Copyright: Tom Masterson
Explanation: You don't have to be at Monument Valley to see the Milky Way arc across the sky like this -- but it helps. Only at Monument Valley USA would you see a picturesque foreground that includes these iconic rock peaks called buttes. Buttes are composed of hard rock left behind after water has eroded away the surrounding soft rock. In the featured image taken in 2012, the closest butte on the left and the butte to its right are known as the Mittens, while Merrick Butte can be seen farther to the right. Green airglow fans up from the horizon. High overhead stretches a band of diffuse light that is the central disk of our spiral Milky Way Galaxy. The band of the Milky Way can bespotted by almost anyone on almost any clear night when far enough from a city and surrounding bright lights, but a sensitive digital camera is needed to capture these colors in a dark night sky.

terça-feira, 25 de julho de 2017

Astronomy picture of the day - 2017 July 25 - A Hybrid Solar Eclipse over Kenya

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A Hybrid Solar Eclipse over Kenya 
Image Credit & Copyright: Eugen Kamenew (Kamenew Photography)
Explanation: Chasing solar eclipses can cause you to go to the most interesting places and meet the most interesting people. Almost. For example, chasing this eclipse brought this astrophotographer to Kenya in 2013. His contact, a member of the Maasai people, was to pick him up at the airport, show him part of southern Kenya, and even agreed to pose in traditional warrior garb on a hill as the hopefully spectacular eclipse set far in background. Unfortunately, this contact person died unexpectedly a week before the astrophotographer's arrival, and so he never got to participate in the shoot, nor know that the resulting image went on to win an international award for astrophotography. Pictured in 2013 from Kenya, the Moon covers much of the Sun during a hybrid eclipse, a rare type of solar eclipse that appears as total from some Earth locations, but annular in others. During the annular part of the eclipse, the Moon was too far from the Earth to block the entire Sun. Next month a total solar eclipse will cross the USA.

domingo, 23 de julho de 2017

Astronomy picture of the day - 2017 July 23 - Mercury as Revealed by MESSENGER

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Mercury as Revealed by MESSENGER 
Image Credit: MESSENGERNASAJHU APLCIW
Explanation: Mercury had never been seen like this before. In 2008, the robotic MESSENGER spacecraft buzzed past Mercury for the second time and imaged terrain mapped previously only by comparatively crude radar. Thefeatured image was recorded as MESSENGER looked back 90 minutes after passing, from an altitude of about 27,000 kilometers. Visible in the image, among many other newly imaged features, are unusually long rays that appear to run like meridians of longitude out from a young crater near the northern limb. MESSENGER entered orbit around Mercury in 2011 and finished its primary mission in 2012, but took detailed measurements until 2015, at which time it ran out of fuel and so was instructed to impact Mercury's surface.

sábado, 22 de julho de 2017

Astronomy picture of the day - 2017 July 22 - Apollo 11: Catching Some Sun

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Apollo 11: Catching Some Sun 
Image Credit: Apollo 11NASA (Image scanned by Kipp Teague)
Explanation: Bright sunlight glints and long dark shadows mark this image of the lunar surface. It was taken July 20, 1969 by Apollo 11 astronaut Neil Armstrong, the first to walk on the MoonPictured is the mission's lunar module, the Eagle, and spacesuited lunar module pilot Buzz Aldrin unfurling a long sheet of foil also known as the Solar Wind Composition Experiment. Exposed facing the Sun, the foil trapped particles streaming outward in the solar wind, catching a sample of material from the Sun itself. Along with moon rocks and lunar soil samples, the solar wind collector was returned for analysis in earthbound laboratories.

sexta-feira, 21 de julho de 2017

Astronomy picture of the day - 2017 July 21 - Phobos: Moon over Mars

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Phobos: Moon over Mars 
Image Credit: NASAESA, Zolt Levay (STScI) - Acknowledgment: J.Bell (ASU) and M.Wolff (SSI)
Explanation: A tiny moon with a scary name, Phobos emerges from behind the Red Planet in this timelapse sequence from the Earth-orbiting Hubble Space Telescope. Over 22 minutes the 13 separate exposures were captured near the 2016 closest approach of Mars to planet Earth. Martians have to look to the west to watch Phobos rise, though. The small moon is closer to its parent planet than any other moon in the Solar System, about 3,700 miles (6,000 kilometers) above the Martian surface. It completes one orbit in just 7 hours and 39 minutes. That's faster than a Mars rotation, which corresponds to about 24 hours and 40 minutes. So on Mars, Phobos can be seen to rise above the western horizon 3 times a day. Still, Phobos is doomed.

Artigo - Saude - Detetada bactéria fecal na McDonald's



Uma bactéria coliforme fecal foi descoberta em amostras de gelo de restaurantes da McDonald's, Burger King e KFC, no Reino Unido, revelou o programa "Watchdog", da BBC.

Em sete restaurantes KFC, seis Burger King e três McDonald's foi detetada a bactéria no gelo e água. De acordo com o jornal Metro, quatro das amostras recolhidas de restaurantes Burger King e cinco da KFC tinham um nível "significante" da bactéria.

De acordo com a DEFRA, o órgão britânico que regula a qualidade da água, não deveria existir a bactéria em questão, em qualquer quantidade, na água usada para consumo humano, diz o Business Insider.

quinta-feira, 20 de julho de 2017

Astronomy picture of the day - 2017 July 20 - IC 1396: Emission Nebula in Cepheus

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IC 1396: Emission Nebula in Cepheus 
Image Credit & Copyright: César Blanco González
Explanation: Stunning emission nebula IC 1396 mixes glowing cosmic gas and dark dust clouds in the high and far off constellation of Cepheus. Energized by the bright central star seen here, this star forming region sprawls across hundreds of light-years, spanning over three degrees on the sky while nearly 3,000 light-years from planet Earth. Among the intriguing dark shapes within IC 1396, the winding Elephant's Trunk nebula lies just below center. Stars could still be forming inside the dark shapes by gravitational collapse. But as the denser clouds are eroded away by powerful stellar winds and radiation, any forming stars will ultimately be cutoff from the reservoir of star stuff. The gorgeous color view is a composition of image data from narrowband filters, mapping emission from the nebula's atomic oxygen, hydrogen, and sulfur into blue, green, and red hues.

quarta-feira, 19 de julho de 2017

Astronomy picture of the day - 2017 July 19 - Ireson Hill on Mars

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Ireson Hill on Mars 
Image Credit: NASAJPL-CaltechMSSS
Explanation: What created this unusual hill on Mars? Its history has become a topic of research, but its shape and two-tone structure makes it one of the more unusual hills that the robotic Curiosity rover on Mars has rolled near. Dubbed Ireson Hill, the mound rises about 5 meters high and spans about 15 meters across. Ireson Hill is located on the Bagnold Dune field on the slope of Mount Sharp in Gale Crater on Mars. The featured 41-image panorama has been horizontally compressed to include the entire hill. The image was taken on February 2 and released last week. Because Mars is moving behind the Sun as seen from the EarthNASA will soon stop sending commands to itsMartian orbiters and rovers until about August 1.

terça-feira, 18 de julho de 2017

Astronomy picture of the day - 2017 July 18 - Thunder Moon over Pisa


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Thunder Moon over Pisa 
Image Credit & Copyright: Marco Meniero
Explanation: What's wrong with this picture? If you figure it out, you may then realize where the image was taken. The oddity lies actually in one of the buildings -- it leans. The Leaning Tower of Pisa has been an iconic legend since shortly after its construction began in the year 1173. Now part of a UNESCO World Heritage Sitefolklore holds that Galileo used the leaning tower to dramatically demonstrate the gravitational principle that objects of different massfall the same. Between the Leaning Tower of Pisa on the right and Pisa Cathedral and the Pisa Baptistery on the left, a full "Thunder" moon was visible last week when the image was taken. Using modern analyses, the tower has been successfully stabilized and, barring the unexpected, should hold its present tilt for the next 200 years.

segunda-feira, 17 de julho de 2017

Astronomy picture of the day - 2017 July 17 - Moon Shadow versus Sun Reflection

Moon Shadow versus Sun Reflection 
Image Credit: Himawari-8, NASA's SVS (GSFC)
Explanation: What are those lights and shadows crossing the Earth? As the featured five-second time-lapse video progresses, a full day on planet Earth is depicted as seen from Japan's Himawari-8 satellite in geostationary orbit high above the Pacific Ocean. The Sun rises to the right and sets to the left, illuminating the half of Earth that is most directly below. A reflected image of the Sun -- a Sun glint -- is visible as a bright spot that moves from right to left. More unusual, though, is the dark spot that moves from the lower left to upper right That is the shadow of the Moon, and it can only appear when the Moon goes directly between the Earth and the Sun. Last year, on the day these images were taken, the most deeply shadowed region experienced a total eclipse of the Sun. Next month a similarly dark shadow will sweep right across the USA.

domingo, 16 de julho de 2017

Astronomy picture of the day - 2017 July 16

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Lightning Eclipse from the Planet of the Goats 
Image Credit & Copyright: Chris Kotsiopoulos (GreekSky)
Explanation: Thunderstorms almost spoiled this view of the spectacular 2011 June 15 total lunar eclipse. Instead, storm clouds parted for 10 minutes during the total eclipse phase and lightning bolts contributed to the dramatic sky. Captured with a 30-second exposure the scene also inspired one of the more memorable titles (thanks to the astrophotographer) in APOD's now 22-year history. Of course, the lightning reference clearly makes sense, and the shadow play of the dark lunar eclipse was widely viewed across planet Earth in Europe, Africa, Asia, and Australia. The picture itself, however, was shot from the Greek island of Ikaria at Pezi. That area is known as "the planet of the goats" because of the rough terrain and strange looking rocks.

sábado, 15 de julho de 2017

Astronomy picture of the day - 2017 July 15 - Close-up of The Great Red Spot

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Close-up of The Great Red Spot 
Image Credit: NASAJunoSwRIMSSSGerald EichstadtSean Doran
Explanation: On July 11, the Juno spacecraft once again swung near to Jupiter's turbulent cloud tops in its looping 53 day orbit around the Solar System's ruling gas giant. About 11 minutes after perijove 7, its closest approach on this orbit, it passed directly above Jupiter's Great Red Spot. During the much anticipated fly over, it captured this close-up image data from a distance of less than 10,000 kilometers. The raw JunoCam data was subsequently processed by citizen scientists. Very long-lived but found to be shrinking, the Solar System's largest storm system was measure to be 16,350 kilometers wide on April 15. That's about 1.3 times the diameter of planet Earth.

sexta-feira, 14 de julho de 2017

Astronomy picture of the day - 2017 July 14 - NGC 4449: Close-up of a Small Galaxy

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NGC 4449: Close-up of a Small Galaxy 
Image Credit & Copyright: Data - Hubble Legacy ArchiveESANASA;
Processing - Domingo Pestana GalvanRaul Villaverde Fraile
Explanation: (xxxedit and linkxxx) Grand spiral galaxies often seem to get all the glory. Their young, blue star clusters and pink star forming regions along sweeping spiral arms are guaranteed to attract attention. But small irregular galaxies form stars too, like NGC 4449, about 12 million light-years distant. Less than 20,000 light-years across, the small island universe is similar in size, and often compared to our Milky Way's satellite galaxy, the Large Magellanic Cloud (LMC). This remarkable Hubble Space Telescope close-up of the well-studied galaxy was reprocessed to highlight the telltale reddish glow of hydrogen gas. The glow traces NGC 4449's widespread star forming regions, some even larger than those in the LMC, with enormous interstellar arcs and bubbles blown by short-lived, massive stars. NGC 4449 is a member of a group of galaxies found in the constellation Canes Venatici. It also holds the distinction of being the first dwarf galaxy with an identified tidal star stream.

quinta-feira, 13 de julho de 2017

Astronomy picture of the day - 2017 July 13 - Full Moon and Boston Light

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Full Moon and Boston Light 
Image Credit & Copyright: Babak Tafreshi (TWAN)
Explanation: This well-planned telephoto timelapse captures July's Full Moon rise across outer Boston Harbor, Massachusetts, planet Earth. In the foreground, the historic terrestrial beacon is known as Boston Light. July's Full Moon is known to some as a Thunder Moon, likely a reference to the sounds of the northern summer month's typically stormy weather. But the eastern sky was clear for this video sequence. Near the horizon, the long sight-line throughatmospheric layers filters and refracts the moonlight, causing the rising Moon's reddened color, ragged edges and distorted shape.

quarta-feira, 12 de julho de 2017

Astronomy picture of the day - 2017 July 12 - Messier 63: The Sunflower Galaxy

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Messier 63: The Sunflower Galaxy 
Image Credit & CopyrightData - Hubble Legacy ArchiveSubaru Telescope (NAOJ), Don Goldman
Processing - Robert GendlerRoberto ColombariDon Goldman



Explanation: A bright spiral galaxy of the northern sky, Messier 63 is about 25 million light-years distant in the loyal constellation Canes Venatici. Also cataloged as NGC 5055, the majestic island universe is nearly 100,000 light-years across. That's about the size of our own Milky Way Galaxy. Known by the popular moniker, The Sunflower Galaxy, M63 sports a bright yellowish core in this sharp composite image from space- and ground-based telescopes. Its sweeping blue spiral arms are streaked with cosmic dust lanes and dotted with pink star forming regions. A dominant member of a known galaxy group, M63 has faint, extended features that are likely star streams from tidally disruptedsatellite galaxies. M63 shines across the electromagnetic spectrum and is thought to have undergone bursts of intense star formation.

terça-feira, 11 de julho de 2017

Astronomy picture of the day - 2017 July 11 - Star Cluster Omega Centauri in HDR

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Star Cluster Omega Centauri in HDR 
Image Credit & Copyright: Mike O'Day
Explanation: Behold the largest ball of stars in our galaxy. Omega Centauri is packed with about 10 million stars, many older than our Sun and packed within a volume of only about 150 light-years in diameter. The star cluster is the largest and brightest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence ofdifferent stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way. The featured image shows so many stars because it merged different exposures with high dynamic range (HDR) techniques. Omega Centauri, also known as NGC 5139, lies about 15,000 light-years away toward the southern constellation of the Centaurus.

segunda-feira, 10 de julho de 2017

Astronomy picture of the day - 2017 July 10 - Spiral Galaxy NGC 1512: The Nuclear Ring

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Spiral Galaxy NGC 1512: The Nuclear Ring 
Image Credit: NASAESAHubbleLEGUSAcknowledgement: Judy Schmidt
Explanation: What's happening around the center of this spiral galaxy? Seen in total, NGC 1512 appears to be a barred spiral galaxy -- a type of spiral that has a straight bar of stars across its center. This bar crosses an outer ring, though, a ring not seen as it surrounds the pictured region. Featured in this Hubble Space Telescope image is an inner ring -- one that itself surrounds the nucleus of the spiral. The two rings are connected not only by a bar of bright stars but by dark lanes of dust. Inside of this inner ring, dust continues to spiral right into the very center -- possibly the location of a large black hole. The rings are bright with newly formed stars which may have been triggered by the collision of NGC 1512 with its galactic neighbor, NGC 1510.

domingo, 9 de julho de 2017

Now, it's time to say goodbye

Résultat de recherche d'images


                    CIAO, CIAO, CIAO...

Astronomy picture of the day - 2017 July 9 - Earth at Night

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Earth at Night 
Image Credit : NASANOAA NGDCSuomi-NPPEarth Observatory,
Data and Processing: Chris Elvidge and Robert Simmon
Explanation: Can you find your favorite country or city? Surprisingly, on this world-wide nightscape, city lights make this task quite possible. Human-made lights highlight particularly developed or populated areas of the Earth's surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts ofSouth AmericaAfricaAsia, and Australia. The featured composite was created from images that were collected during cloud-free periods in April and October 2012 by the Suomi-NPP satellite, from a polar orbit about 824 kilometers above the surface, using its Visible Infrared Imaging Radiometer Suite (VIIRS).

sábado, 8 de julho de 2017

Astronomy picture of the day - 2017 July 8 - Hidden Galaxy IC 342

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Hidden Galaxy IC 342 
Credit & CopyrightT. Rector (U. Alaska Anchorage), H. SchweikerWIYNNOAOAURANSF
Explanation: Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342's light is dimmed by intervening cosmic clouds, this sharp telescopic image traces the galaxy's own obscuring dust, blue star clusters, and glowing pink star forming regions along spiral arms that wind far from the galaxy's core. IC 342 may have undergone a recent burst of star formation activity and is close enough to have gravitationally influenced the evolution of the local group of galaxies and the Milky Way.

sexta-feira, 7 de julho de 2017

Astronomy picture of the day - 2017 July 7 - A View Toward M106

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A View Toward M106 
Image Credit & CopyrightPeter Feltoti



Explanation: Big, bright, beautiful spiral, Messier 106 dominates this cosmic vista. The two degree wide telescopic field of view looks toward the well-trained constellation Canes Venatici, near the handle of the Big Dipper. Also known as NGC 4258, M106 is about 80,000 light-years across and 23.5 million light-years away, the largest member of the Canes II galaxy group. For a far away galaxy, the distance to M106 is well-known in part because it can bedirectly measured by tracking this galaxy's remarkable maser, or microwave laser emission. Very rare but naturally occuring, the maser emission is produced by water molecules in molecular clouds orbiting its active galactic nucleus. Another prominent spiral galaxy on the scene, viewed nearly edge-on, is NGC 4217 below and right of M106. The distance to NGC 4217 is much less well-known, estimated to be about 60 million light-years.

quinta-feira, 6 de julho de 2017

Imagens - Monumentos de Portugal - Convento de Cristo - Tomar

É um convento fortificado construído ao longo de cinco séculos e que, por isso, resultou num intrincado complexo de edifícios de vários estilos e idades. A construção original remonta aos Templários, que aqui mantiveram a sede em Portugal dos Cavaleiros da Ordem de Cristo. O Infante D. Henrique foi um dos grão-mestres mais famosos da Ordem, que custeou as suas explorações marítimas. O Convento de Cristo foi também o local onde se formou a União Ibérica, em 1581, quando Filipe II de Espanha se tornou também reconhecido como Filipe I de Portugal.

Astronomy picture of the day - 2017 July 6 - Atlas, Daphnis, and Pan

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Atlas, Daphnis, and Pan 
Image Credit: Cassini Imaging TeamSSIJPLESANASA
Explanation: AtlasDaphnis, and Pan are small, inner, ring moons of Saturn, shown at the same scale in this montage of images from the still Saturn-orbiting Cassini spacecraft. In fact, Daphnis was discovered in Cassini images from 2005. Atlas and Pan were first sighted in images from the Voyager 1 and 2 spacecraft. Flying saucer-shaped Atlas orbits near the outer edge of Saturn's bright A Ring while Daphnis orbits inside the A Ring's narrow Keeler Gap and Pan within the A Ring's larger Encke Gap. The curious equatorial ridges of the small ring moons could be built up by the accumulation of ring material over time. Even diminutive Daphnis makes waves in the ring material as it glides along the edge of the Keeler Gap.

quarta-feira, 5 de julho de 2017

Astronomy picture of the day - 2017 July 5 - Aphelion Sunrise

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Aphelion Sunrise 
Image Credit & CopyrightStephen Mudge
Explanation: On July 3rd, planet Earth reached aphelion, the farthest point in its elliptical orbit around the Sun. Each year, this day of the most distant Sun happens to occur during winter in the southern hemisphere. That's where this aphelion sunrise from 2015 was captured in a time series composite against the skyline of Brisbane, Australia. Of course, seasons for our fair planet are not determined by distance to the Sun, but by the tilt of Earth's rotational axis with respect to the ecliptic, the plane of its orbit. Fondly known as the obliquity of the ecliptic, the angle of the tilt is about 23.4 degrees from perpendicular to the orbital plane. So the most distant sunrise occurs during northern summer, when the planet's north pole is tilted toward the Sun and the north enjoys longer, warmer days.

terça-feira, 4 de julho de 2017

Astronomy picture of the day - 2017 July 4 - Celestial Fireworks: Into Star Cluster Westerlund 2

Celestial Fireworks: Into Star Cluster Westerlund 2 
Visualization Credit: NASA, ESA, Hubble, J. Anderson et al. (STScI); Acknowledgment: The Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), the Westerlund 2 Science Team, and the ESO
Explanation: What if you could go right into a cluster where stars are forming? A one-minute, time-lapse, video visualization of just this has been made with 3D computer modeling of the region surrounding the star cluster Westerlund 2, based on images from the Hubble Space Telescope in visible and infrared light. Westerlund 2 spans about 10 light years across and lies about 20,000 light years distant toward the constellation of the Ship's Keel (Carina). As theillustrative animation begins, the greater Gum 29 nebula fills the screen, with the young cluster of bright stars visible in the center. Stars zip past you as you approach the cluster. Soon your imaginary ship pivots and you pass over light-year long pillars of interstellar gas and dust. Strong winds and radiation from massive young stars destroy all but the densest nearby dust clumps, leaving these pillars in their shadows -- many pointing back toward the cluster center. Last, you pass into the top of the star cluster and survey hundreds of the most massive stars known.

segunda-feira, 3 de julho de 2017

Astronomy picture of the day - 2017 July 3 - Mountains of Dust in the Carina Nebula

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Mountains of Dust in the Carina Nebula 
Image Credit: NASAESA, and M. Livio (STScI)
Explanation: It's stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and known informally as Mystic Mountain, these pillar's appearance is dominated by the dark dust even though it is composed mostly of clear hydrogen gas. Dust pillars such as these are actually much thinner than air and only appear as mountains due to relatively small amounts of opaque interstellar dust. About 7,500 light-years distant, the featured image was taken with the Hubble Space Telescope and highlights an interior region of Carina which spans about three light years. Within a few million years, the stars will likely win out completely and the entire dust mountain will evaporate.