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30/11/2019

Science & Technology - Astronomy picture of the day : A Cold River to Orion

2018 November 30
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A Cold River to Orion 
Image Credit & CopyrightJuris Sennikovs
Explanation: Ice is forming on the river Lielupe as it flows through the landscape in this winter's night scene. Even in motion the frigid water still reflects a starry sky, though. The well planned, Orion-centered panorama looks toward the south, taken in three exposures from a bridge near the village of Stalgene, Latvia, planet Earth. Drifting pancakes of ice leave streaks in the long exposures, while familiar stars of Orion and the northern winter night appear above and below the horizon. Village lights along the horizon include skyward beams from the local community church. This image was a first place winner in the 2018 StarSpace astrophotography competition.

25/11/2019

Science & Technology - Astronomy picture of the day : NGC 6995: The Bat Nebula

2019 November 25
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NGC 6995: The Bat Nebula 
Image Credit & Copyright: Josep Drudis
Explanation: Do you see the bat? It haunts this cosmic close-up of the eastern Veil NebulaThe Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape and covers nearly 3 degrees on the sky toward the constellation of the Swan (Cygnus), the Bat Nebula, NGC 6995, spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's estimated distance, a reassuring 1,400 light-years from planet Earth. In the composite of image data recorded through broad and narrow band filters, emission from hydrogen atoms in the remnant is shown in red with strong emission from oxygen and nitrogen atoms shown in hues of blue. Of course, in the western part of the Veil lies another seasonal apparition: the Witch's Broom Nebula.

22/11/2019

Science & Technology - Astronomy picture of the day : Orion Rising

2019 November 22
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Orion Rising 
Image Credit & Copyright: Vitalij Kopa
Explanation: Looking toward the east in the early hours of a September morning this single exposure made with tripod and camera captured a simple visual experience. Rising above the tree-lined slope are familiar stars in planet Earth's northern night and the constellation Orion the Hunter. Brighter stars marking the celestial Hunter's shoulder (Betelgeuse), foot (Rigel), belt, and sword are clearly reflected in the calm waters from northern Latvia's Vitrupe river. Of course, winter is coming to planet Earth's northern hemisphere. By then Orion and this beautiful starry vista will be seen rising in early evening skies.

20/11/2019

Ciência & Tecnologia - Saude/Medecina : Fornos de microondas, perigo ?

A imagem pode conter: texto

Science & Technology - Astronomy picture of the day : Arp 273: Battling Galaxies from Hubble

2019 November 20
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Arp 273: Battling Galaxies from Hubble 
Image Credit: NASAESAHubbleProcessing & Copyright: Rudy Pohl
Explanation: What's happening to these spiral galaxies? Although details remain uncertain, there sure seems to be a titanic battle going on. The upper galaxy is labelled UGC 1810 by itself, but together with its collisional partners is known as Arp 273. The overall shape of the UGC 1810 -- in particular its blue outer ring -- is likely a result of wild and violent gravitational interactions. The blue color of the outer ring at the top is caused by massive stars that are blue hot and have formed only in the past few million years. The inner part of the upper galaxy -- itself an older spiral galaxy -- appears redder and threaded with cool filamentary dust. A few bright stars appear well in the foreground, unrelated to colliding galaxies, while several far-distant galaxies are visible in the background. Arp 273 lies about 300 million light years away toward the constellation of Andromeda. Quite likely, UGC 1810 will devour its galactic sidekicks over the next billion years and settle into a classic spiral form.

19/11/2019

Science & Technology - Astronomy picture of the day : Milky Way over Uruguayan Lighthouse

2019 November 19
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Milky Way over Uruguayan Lighthouse 
Image Credit & Copyright: Mauricio Salazar
Explanation: Can a lighthouse illuminate a galaxy? No, but in the featured image, gaps in light emanating from the Jose Ignacio Lighthouse in Uruguay appear to match up nicely, although only momentarily and coincidently, with dark dust lanes of our Milky Way Galaxy. The bright dot on the right is the planet Jupiter. The central band of the Milky Way Galaxy is actually the central spiral disk seen from within the disk. The Milky Way band is not easily visiblethrough city lights but can be quite spectacular to see in dark skies. The featured picture is actually the addition of ten consecutive images taken by the same camera from the same location. The images were well planned to exclude direct light from the famous lighthouse.

18/11/2019

Ciência e Tecnologia - Saude/Medecina : "Canabis, bom para a saude ?"




Investigadores da Universidade de Western Ontário, no Canadá, realizaram um estudo com vista a perceber os diferentes efeitos psicológicos que a canábis provoca nos consumidores. Publicado este mês na revista Scientific Reports, o estudo representa um grande avanço na compreensão dos efeitos da droga no cérebro humano.

A pergunta de partida para a investigação era há muito uma grande dúvida dos cientistas e da população em geral: qual o motivo de algumas pessoas terem emoções positivas como reação ao consumo de canábis e outras demonstrarem emoções negativas.

Segundo Steven Laviolette, um dos autores do estudo, a premissa levou os investigadores para um campo ainda pouco explorado. “Sabemos muito sobre os efeitos a longo e a curto prazo, mas há muito pouco conhecimento sobre as áreas específicas do cérebro que são responsáveis pelo controlo desses efeitos”.

E a resposta pode ter a ver com as diferentes partes do cérebro, em particular, qual das partes é mais sensível ao tetraidrocanabinol (THC), substância psicoativa libertada pela canábis. Em algumas pessoas, a parte do cérebro mais sensível é a frontal e, nesse caso, provoca sentimentos de conforto, tranquilidade e felicidade. Se a parte mais sensível à substância for a região posterior do cérebro, a droga fará a pessoa sentir medo e alguma paranoia infundada.

Esta investigação foi realizada em ratos de laboratório, mas os cientistas acreditam estar muito mais perto da verdade sobre os efeitos da canábis nos seres humanos. O próximo passo passará sobretudo pela experiência relatada por aqueles que consomem.

Visão - Portugal

17/11/2019

Science & Technology - Astronomy picture of the day : Young Stars in the Rho Ophiuchi Cloud

2019 November 17
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Young Stars in the Rho Ophiuchi Cloud 
Image Credit: NASAJPL-CaltechWISE
Explanation: How do stars form? To help find out, astronomers created this tantalizing false-color composition of dust clouds and embedded newborn stars in infrared wavelengths with WISE, the Wide-field Infrared Survey Explorer. The cosmic canvas features one of the closest star forming regions, part of the Rho Ophiuchi cloud complex some 400 light-years distant near the southern edge of the pronounceable constellation Ophiuchus. After forming along a large cloud of cold molecular hydrogen gas, young stars heat the surrounding dust to produce the infrared glow. Stars in the process of formation, called young stellar objects or YSOs, are embedded in the compact pinkish nebulae seen here, but are otherwise hidden from the prying eyes of optical telescopes. An exploration of the region in penetrating infrared light has detected emerging and newly formed stars whose average age is estimated to be a mere 300,000 years. That's extremely young compared to the Sun's age of 5 billion years. The prominent reddish nebula at the lower right surrounding the star Sigma Scorpii is a reflection nebula produced by dust scattering starlight. This view from WISE, released in 2012, spans almost 2 degrees and covers about 14 light-years at the estimated distance of the Rho Ophiuchi cloud.

16/11/2019

Science & Technology - Astronomy picture of the day : The Star Streams of NGC 5907

2019 November 16
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The Star Streams of NGC 5907 
Image Credit & Copyright: R Jay Gabany (Blackbird Observatory) - collaboration; D.Martinez-Delgado(IACMPIA),
J.Penarrubia (U.Victoria) I. Trujillo (IAC) S.Majewski (U.Virginia), M.Pohlen (Cardiff)
Explanation: Grand tidal streams of stars seem to surround galaxy NGC 5907. The arcing structures form tenuous loops extending more than 150,000 light-years from the narrow, edge-on spiral, also known as the Splinter or Knife Edge Galaxy. Recorded only in very deep exposures, the streams likely represent the ghostly trail of a dwarf galaxy - debris left along the orbit of a smaller satellite galaxy that was gradually torn apart and merged with NGC 5907 over four billion years ago. Ultimately this remarkable discovery image, from a small robotic observatory in New Mexico, supports the cosmological scenario in which large spiral galaxies, including our own Milky Way, were formed by the accretion of smaller ones. NGC 5907 lies about 40 million light-years distant in the northern constellation Draco.

15/11/2019

Music - Live - Video -Copernicus Chamber Orchestra & Horst Sohm - (Haendel) : "The Sarabande in D minor "

"The Sarabande in D minor "

Science & Technology - Astronomy picture of the day : M16 and the Eagle Nebula

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M16 and the Eagle Nebula 
Image Credit & Copyright: Martin Pugh

Explanation: A star cluster around 2 million years young surrounded by natal clouds of dust and glowing gas, M16 is also known as The Eagle Nebula. This beautifully detailed portrait of the region was made with groundbased narrow and broadband image data. It includes cosmic sculptures made famous in Hubble Space Telescope close-ups of the starforming complex. Described as elephant trunks or Pillars of Creation, dense, dusty columns rising near the center are light-years in length but are gravitationally contracting to form stars. Energetic radiation from the cluster stars erodes material near the tips, eventually exposing the embedded new stars. Extending from the ridge of bright emission at lower left is another dusty starforming column known as the Fairy of Eagle Nebula. M16 lies about 7,000 light-years away, an easy target for binoculars or small telescopes in a nebula rich part of the sky toward the split constellationSerpens Cauda (the tail of the snake).

14/11/2019

Science & Technology - Astronomy picture of the day : Curiosity Rover Finds a Clay Cache on Mars

2019 October 29
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Curiosity Rover Finds a Clay Cache on Mars 
Image Credit: NASAJPL-CaltechMSSS
Explanation: Why is there clay on Mars? On Earth, clay can form at the bottom of a peaceful lake when specific minerals trap water. At the pictured site on Mars, the robotic rover Curiosity drilled into two rocks and found the highest concentration of clay yet. The clay cache is considered addition evidence that Gale Crater once held water in the distant past. Pictured, 57 images taken by Curiosity have been combined into a selfie. The images were taken by a camera at the end of its robotic arm. Many details of the car-sized rover are visible, including its rugged wheels, numerous scientific instruments, and a high mast that contains camera "eyes", one of which can shoot out an infrared laser beam. Curiosity continues to roll around and up Mount Sharp -- in the center of Gale Crater -- in a search for new clues about the ancient history of Mars and whether or not the red planet once had conditions that could support life.

13/11/2019

Science & Technology - Astronomy picture of the day : Comet Halley's Nucleus

November 13, 2019
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Comet Halley's Nucleus
Credit:
 Halley Multicolour Camera Team, GiottoESA
CopyrightMPAE
Explanation: Here is what a comet nucleus really looks like. For all active comets except Halley, it was only possible to see the surrounding opaque gas cloud called the coma. During Comet Halley's most recent pass through the innerSolar System in 1986, however, spacecraft Giotto was able to go right up to the comet and photograph its nucleus. The above image is a composite of hundreds of these photographs. Although the most famous comet, Halley achieved in 1986 only 1/10th the brightness that Comet Hyakutake did last year, and a similar comparison is likely with next year's pass of Comet Hale-Bopp. Every 76 years Comet Halley comes around again, and each time the nucleus sheds about 6 meters of ice and rock into space. This debris composes Halley's tails and leaves an orbiting trail that, when falling to Earth, are called the Orionids Meteor Shower.

12/11/2019

Musica - Video - Monteverdi : "Lamento della Ninfa"

"Lamento della Ninfa"

Science & Technology - Astronomy picture of the day : NGC 3717 : A Nearly Sideways Spiral Galaxy

2019 November 12
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NGC 3717: A Nearly Sideways Spiral Galaxy 
Image Credit: ESA/Hubble & NASAProcessing: D. Rosario
Explanation: Some spiral galaxies are seen nearly sideways. Most bright stars in spiral galaxies swirl around the center in a disk, and seen from the side, this disk can be appear quite thin. Some spiral galaxies appear even thinner thanNGC 3717, which is actually seen tilted just a bit. Spiral galaxies form disks because the original gas collided with itself and cooled as it fell inward. Planets may orbit in disks for similar reasons. The featured image by the Hubble Space Telescope shows a light-colored central bulge composed of older stars beyond filaments of orbiting dark brown dustNGC 3717 spans about 100,000 light years and lies about 60 million light years away toward the constellation of the Water Snake (Hydra).

11/11/2019

Science & Technology - Astronomy picture of the day : Lunar Craters Langrenus and Petavius

2019 November 11
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Lunar Craters Langrenus and Petavius 
Image Credit & Copyright: Eduardo Schaberger Poupeau
Explanation: The history of the Moon is partly written in its craters. Pictured here is a lunar panorama taken from Earth featuring the large craters Langrenus, toward the left, and Petavius, toward the right. The craters formed in separate impactsLangrenus spans about 130 km, has a terraced rim, and sports a central peak rising about 3 km. Petavius is slightly larger with a 180 km diameter and has a distinctive fracture that runs out from its center. Although it is known that Petravius crater is about 3.9 billion years old, the origin of its large fracture is unknown. The craters are best visible a few days after a new Moon, when shadows most greatly accentuate vertical walls and hills. Thefeatured image is a composite of the best of thousands of high-resolution, infrared, video images taken through a small telescope. Although mountains on Earth will likely erode into soil over a billion years, lunar craters Langrenus and Petavius will likely survive many billions more years, possibly until the Sun expands and engulfs both the Earth and Moon.

10/11/2019

Science & Technology - Astronomy picture of the day : A Mercury Transit Sequence

2019 November 10
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A Mercury Transit Sequence 
Image Credit & Copyright: Dominique Dierick
Explanation: Tomorrow -- Monday -- Mercury will cross the face of the Sun, as seen from Earth. Called a transit, the last time this happened was in 2016. Because the plane of Mercury's orbit is not exactly coincident with the plane of Earth's orbit, Mercury usually appears to pass over or under the Sun. The featured time-lapse sequence, superimposed on a single frame, was taken from a balcony in Belgium shows the entire transit of 2003 May 7. That solar crossing lasted over five hours, so that the above 23 images were taken roughly 15 minutes apart. The north pole of the Sun, the Earth's orbit, and Mercury's orbit, although all different, all occur in directions slightly above the left of the image. Near the center and on the far right, sunspots are visible. After Monday, the next transit of Mercury will occur in 2032.

09/11/2019

Sciece & Technology - Astronomy picture of the day : Saturn the Giant

2019 November 9
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Saturn the Giant 
Image Credit: NASA
Explanation: On May 25, 1961 U.S. president John Kennedy announced the goal of landing astronauts on the Moon by the end of the decade. By November 9, 1967 this Saturn V rocket was ready for launch and the first full test of its capabilities on the Apollo 4 mission. Its development directed by rocket pioneer Wernher Von Braun, the three stage Saturn V stood over 36 stories tall. It had a cluster of five first stage engines fueled by liquid oxygen and kerosene which together were capable of producing 7.9 million pounds of thrust. Giant Saturn V rockets ultimately hurled nine Apollo missions to the Moon and back again with six landing on the lunar surface. The first landing mission, Apollo 11, achieved Kennedy's goal on July 20, 1969.

07/11/2019

Science & Technology - Astronomy picture of the day - Messier 45: The Daughters of Atlas and Pleione

2019 November 7
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Messier 45: The Daughters of Atlas and Pleione 
Image Credit & Copyright: Adam BlockSteward Observatory, University of Arizona
Explanation: Hurtling through a cosmic dust cloud a mere 400 light-years away, the lovely Pleiades or Seven Sisters open star cluster is well-known for its striking blue reflection nebulae. It lies in the night sky toward the constellation Taurus and the Orion Arm of our Milky Way Galaxy. The sister stars and cosmic dust cloud are not related though, they just happen to be passing through the same region of space. Known since antiquity as a compact grouping of stars, Galileo first sketched the star cluster viewed through his telescope with stars too faint to be seen by eye. Charles Messier recorded the position of the cluster as the 45th entry in his famous catalog of things which are not comets. In Greek myth, the Pleiades were seven daughters of the astronomical Titan Atlas and sea-nymph Pleione. Their parents names are included in the cluster's nine brightest stars. This deep and wide telescopic image spans over 20 light-years across the Pleides star cluster.

06/11/2019

Science & Technology - Astronomy picture of the day : 21st Century M101

2019 November 6
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21st Century M101 
Image Credit: NASAESACXCJPL - CaltechSTScI
Explanation: One of the last entries in Charles Messier's famous catalog, big, beautiful spiral galaxy M101 is definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy. M101 was also one of the original spiral nebulae observed with Lord Rosse's large 19th century telescope, the Leviathan of Parsonstown. In contrast, this multiwavelength view of the large island universe is a composite of images recorded by space-based telescopes in the 21st century. Color coded from X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (purple), theGalaxy Evolution Explorer (blue), Hubble Space Telescope(yellow), and the Spitzer Space Telescope(red). While the X-ray data trace the location of multimillion degree gas around M101's exploded stars and neutron star and black hole binary star systems, the lower energy data follow the stars and dust that define M101's grand spiral arms. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away.

05/11/2019

Science & Technology - Astronomy picture of the day : Spiral Galaxies Spinning Super-Fast

2019 November 5
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Spiral Galaxies Spinning Super-Fast 
Image Credit: Top row: NASAESAHubble, P. Ogle & J. DePasquale (STScI);
Bottom row: SDSS, P. Ogle & J. DePasquale (STScI)
Explanation: Why are these galaxies spinning so fast? If you estimated each spiral's mass by how much light it emits, their fast rotations should break them apart. The leading hypothesis as to why these galaxies don't break apart isdark matter -- mass so dark we can't see it. But these galaxies are even out-spinning this break-up limit -- they are the fastest rotating disk galaxies known. It is therefore further hypothesized that their dark matter halos are so massive -- and their spins so fast -- that it is harder for them to form stars than regular spirals. If so, then these galaxies may be among the most massive spirals possible. Further study of surprising super-spirals like these will continue, likely including observations taken by NASA's James Webb Space Telescope scheduled for launch in 2021.

04/11/2019

Science & Technology - Astronomy picture of the day : Near the Center of the Lagoon Nebula

2019 November 4
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Near the Center of the Lagoon Nebula 
Image Credit & Copyright: Zhuoqun Wu, Chilescope
Explanation: Stars are battling gas and dust in the Lagoon Nebula but the photographers are winning. Also known as M8, this photogenic nebula is visible even without binoculars towards the constellation of the Archer (Sagittarius). The energetic processes of star formation create not only the colors but the chaos. The glowing gas results from high-energy starlight striking interstellar hydrogen gas and trace amounts of sulfur, and oxygen gases. The dark dustfilaments that lace M8 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions. The light from M8 we see today left about 5,000 years ago. Light takes about 50 years to cross this section of

03/11/2019

Science & Technology - Astronomy picture of the day : Daphnis and the Rings of Saturn

2019 November 3
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Daphnis and the Rings of Saturn 
Image Credit: NASAJPL-CaltechSpace Science InstituteCassini
Explanation: What's happening to the rings of Saturn? A little moon making big waves. The moon is 8-kilometer Daphnis and it is making waves in the Keeler Gap of Saturn's rings using just its gravity -- as it bobs up and down, in and out. The featured image is a colored and more detailed version of a previously released images taken in 2017 by the robotic Cassini spacecraft during one of its Grand Finale orbitsDaphnis can be seen on the far right, sporting ridges likely accumulated from ring particlesDaphnis was discovered in Cassini images in 2005 and raised mounds of ring particles so high in 2009 -- during Saturn's equinox when the ring plane pointed directly at the Sun -- that they cast notable shadows.

01/11/2019

Science & Technology - Astronomy picture of the day : The Day After Mars

2019 November 1
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The Day After Mars 
Image Credit & Copyright: Rolando Ligustri (CARA ProjectCAST)
Explanation: October 31, 1938 was the day after Martians encountered planet Earth, and everything was calm. Reports of the invasion were revealed to be part of a Halloween radio drama, the now famous broadcast based on H.G. Wells' scifi novel War of the Worlds. On Mars October 20, 2014 was calm too, the day after its close encounter with Comet Siding Spring (C/2013 A1). Not a hoax, this comet really did come within 86,700 miles or so of Mars, about 1/3 the Earth-Moon distance. Earth's spacecraft and rovers in Mars orbit and on the surface reported no ill effects though, and had a ringside seat as a visitor from the outer solar system passed by. Spanning over 2 degrees against stars of the constellation Ophiuchus, this colorful telescopic snapshot captures our view of Mars on the day after. Bluish star 51 Ophiuchi is at the upper right and the comet is just emerging from the Red Planet's bright glare.

SANTé/MEDECINE - Virus et bactéries mortels - Le virus de la rage

Grâce aux travaux de Louis Pasteur , la rage a très nettement reculé dans le monde. On dénombre tout de même plus de 50.000 morts humains s...