Science & Technology - Astronomy picture of the day : Enhanced: The Dolphin Cloud on Jupiter

2019 April 15
Enhanced: The Dolphin Cloud on Jupiter Image Credit: NASA, Juno, SwRI, MSSS; Processing: Gerald Eichstädt & Avi Solomon

Explanation: Do you see the dolphin-shaped cloud on Jupiter? The cloud was visible last year during perijove 16, the sixteenth time that NASA's robotic spacecraft Juno passed near Jupiter since it arrived in mid-2016. During each perijove, Juno passes near a slightly different part of Jupiter's cloud tops. The dolphin shape may be surprising but is not scientifically significant -- clouds on Jupiter and Earth are constantly shifting and can temporarily mimic many familiar shapes. The cloud appears in Jupiter's South Temperate Belt (STB), a band of dark and dropping clouds that rings the planet and also contains Oval BA, dubbed Red Spot Jr. The featured image was digitally processed to enhance color and contrast. Juno's next swoop near Jupiter -- perijove 20 -- will occur on late May.

Cência e Tecnologia - Video : Filmada queda de um meteorito no Brasil

O clarão deixado nos céus de Taquara, no estado do Rio Grande do Sul foi registado na madrugada de sexta-feira, 12 de abril, e corresponde a um meteorito. O momento foi captado por uma das câmaras da Rede Brasileira de Observação de Meteoritos (BRAMON, sigla em inglês).

O professor Carlos Fernando Jung, diretor do BRAMON e responsável pelo registo em vídeo da queda do meteorito conta ao site G1 que o "objeto" pesava "12 quilos quando entrou na atmosfera" a 122,2 mil quilómetros por hora, tendo começado a perder força. Não terá atingido o solo. "Os fragmentos foram mínimos", diz. Após análise ao fenómeno, o especialista calcula que o meteorito desfragmentou-se a 36 quilómetros de altitude e não causou qualquer dado.

"O objeto foi totalmente consumido na sua passagem atmosférica, a cerca de 145 quilómetros sobre o mar da costa do Rio Grande do Sul", explica Jung.

Diario de Noticias - Portugal

Santé et Médecine : Les rideaux des chambres d’hôpital sont des nids à bactéries

Les rideaux qui séparent les lits des malades dans de nombreux hôpitaux sont censés protéger leur intimité, mais ils pourraient bien menacer leur santé. Ils sont souvent porteurs de bactéries résistantes qui peuvent ensuite contaminer les patients, selon une étude publiée vendredi. Ainsi, 1.500 prélèvements ont été réalisés et des bactéries multirésistantes ont été détectées dans plus d’un cas sur cinq. Fréquemment, les patients étaient porteurs de la même bactérie que celle détectée sur leur rideau.

« Ces agents pathogènes peuvent survivre sur ces rideaux et, potentiellement, se transférer sur d’autres surfaces et sur les patients. Dans la mesure où ces rideaux sont utilisés partout, c’est un problème mondial », a affirmé l’une des auteurs de l’étude, Lona Mody, docteur et chercheuse à l’université du Michigan (Etats-Unis).

Le patient porteur de la même bactérie dans 16 % des cas

Les prélèvements ont été réalisés sur le bord des rideaux, là où ils sont le plus fréquemment touchés. Résultat : 22 % de ces échantillons étaient positifs à des bactéries multirésistantes. Dans le détail, près de 14 % étaient contaminés à des entérocoques résistant à la vancomycine, plus de 6 % à des bactéries à Gram négatif résistantes, et près de 5 % à un staphylocoque doré résistant à la méticilline, autant de bactéries potentiellement mortelles.

20 Minutes - France

Science & Technology - Astronomy picture of the day : Wisps Surrounding the Horsehead Nebula

2019 April 3
Wisps Surrounding the Horsehead Nebula Image Credit & Copyright: Mario Zauner

Explanation: The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas. To bring out details of the Horsehead's pasture, an amateur astronomer used a backyard telescope in Austria to accumulate and artistically combine 7.5 hours of images in the light of Hydrogen (red), Oxygen (green), and Sulfur (blue). The resulting spectacular picture details an intricate tapestry of gaseous wisps and dust-laden filaments that were created and sculpted over eons by stellar winds and ancient supernovas. The Flame Nebula is visible just to the left of the Horsehead, while the bright star on the upper left is Alnilam, the central star in Orion's Belt. The Horsehead Nebula lies 1,500 light years distant towards the constellation of Orion.

Science & Technology - Astronomy picture of the day : A Cosmic Rose: The Rosette Nebula in Monoceros

2019 April 13
A Cosmic Rose: The Rosette Nebula in Monoceros  
Image Credit & Copyright: Jean Dean

Explanation: The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is the most famous. At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young, O-type stars. Stars in the energetic cluster, cataloged as NGC 2244, are only a few million years young, while the central cavity in the Rosette Nebula, is about 50 light-years in diameter. The nebula can be seen with a small telescope toward the constellation of Monoceros, the Unicorn. This natural appearing telescopic portrait of the Rosette Nebula was made using broadband and narrowband filters, because sometimes roses aren't red.

Science & Technologie - Le monde des requins : Le requin-marteau : une bonne Tête avec un grand T

Reconnaissables à leur tête en forme de T, les requins-marteaux regroupent dix espèces de la famille des Sphyrnidés. Ils sont en général de taille modeste, mais le plus imposant d'entre eux, legrand requin marteau (Sphyrna mokarran), peut mesurer jusqu'à 6 mètres de long pour 450 kg. Ils évoluent en bancs le jour, puis se muent en loups solitaires la nuit pour chasser. Leur tête de marteau devient alors un outil très efficace. Ils bénéficient d'un champ de vision élargi, car leursyeux sont placés aux deux extrémités de ces protubérances, et peuvent clouer au sol les raies, pour lesquelles ils ont une petite préférence.

Certaines espèces de requins marteaux sont considérées comme vulnérables par l'UICN. D'autres sont classées en danger : c'est le cas du grand requin marteau.

© Martin, Fotolia

Science & Technology - Astronomy picture of the day : AZURE Vapor Tracers over Norway

2019 April 8
AZURE Vapor Tracers over Norway 
Image Credit & Copyright: Yang Sutie

Explanation: What's happening in the sky? The atmosphere over northern Norway appeared quite strange for about 30 minutes last Friday when colorful clouds, dots, and plumes suddenly appeared. The colors were actually created by the NASA-funded Auroral Zone Upwelling Rocket Experiment (AZURE) which dispersed gas tracers to probe winds in Earth's upper atmosphere. AZURE's tracers originated from two short-lived sounding rockets launched from the Andøya Space Center in Norway. The harmless gases, trimethylaluminum and a barium/strontium mixture, were released into the ionosphere at altitudes of 115 and 250 km. The vapor trails were observed dispersing from several ground stations. Mapping how AZURE's vapors dispersed should increase humanity's understanding of how the solar wind transfers energy to the Earth and powers aurora.

Science & Technology - Astronomy picture of the day : First Horizon-Scale Image of a Black Hole

2019 April 11
First Horizon-Scale Image of a Black Hole Image Credit: Event Horizon Telescope Collaboration

Explanation: What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas. The first image was released yesterday and resolved the area around the black hole at the center of galaxy M87 on a scale below that expected for its event horizon.Pictured, the dark central region is not the event horizon, but rather the black hole's shadow -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gasnear the event horizon, by strong gravitational lensing deflections, and by the black hole's spin. In resolving this black hole's shadow, the Event Horizon Telescope (ETH) bolstered evidence that Einstein's gravity works even in extreme regions, and gave clear evidence that M87 has a central spinning black hole of about 6 billion solar masses. The EHT is not done -- future observations will be geared toward even higher resolution, better tracking of variability, and exploring the immediate vicinity of the black hole in the center of our Milky Way Galaxy.

Science & Technology - Astronomy picture of the day : A Scorpius Sky Spectacular

019 April 7
A Scorpius Sky Spectacular Image Credit & Copyright: Stéphane Guisard, TWAN

Explanation: If Scorpius looked this good to the unaided eye, humans might remember it better. Scorpius more typically appears as a few bright stars in a well-known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, color filters, and a digital image processor. To bring out detail, the featured image not only involved long duration exposures taken in several colors, but one exposure in a very specific red color emitted by hydrogen. The resulting image shows many breathtaking features. Vertically across the image left is part of the plane of our Milky Way Galaxy. Visible there are vast clouds of bright stars and long filaments of darkdust. Jutting out diagonally from the Milky Way in the image center are dark dust bands known as the Dark River. This river connects to several bright stars on the right that are part of Scorpius' head and claws, and include the bright star Antares. Above and right of Antares is an even brighter planet: Jupiter. Numerous red emission nebulas and blue reflection nebulas are visible throughout the image. Scorpius appears prominently in southern skies after sunset during the middle of the year.

Science & Technology - Astronomy picture of the day : Messier 2

2019 April 4
Messier 2 Image Credit: ESA/Hubble & NASA, G. Piotto et al.

Explanation: After the Crab Nebula, M1, this giant star cluster is the second entry in 18th century astronomer Charles Messier's famous list of things with are not comets. M2 is one of the largest globular star clusters now known to roam the halo of our Milky Way galaxy. Though Messier originally described it a nebula without stars, this stunning Hubble image resolves stars across the central 40 light-years of M2. Its population of stars numbers close to 150,000, concentrated within a total diameter of around 175 light-years. About 55,000 light-years distant toward the constellation Aquarius, this ancient denizen of the Milky Way, also known as NGC 7089, is 13 billion years old.