Minha neta Oliana
12-02-2017
JoanMira
2017-02-27
Astronomy picture of the day - 2017 February 27 - Four Quasar Images Surround a Galaxy Lens
Image Credit: ESA/Hubble, NASA, Sherry Suyu et al.
Explanation: An odd thing about the group of lights near the center is that four of them are the same distant quasar. This is because the foreground galaxy -- in the center of the quasar images and the featured image -- is acting like a choppy gravitational lens. A perhaps even odder thing is that by watching these background quasars flicker, you can estimate the expansion rate of the universe. That is because the flicker timing increases as the expansion rate increases. But to some astronomers, the oddest thing of all is that these multiply imaged quasars indicate a universe that is expanding a bit faster than has been estimated by different methods that apply to the early universe. And that is because ... well, no one is sure why. Reasons might include an unexpected distribution of dark matter, some unexpected effect of gravity, or something completely different. Perhaps future observations and analyses of this and similarly lensed quasar images will remove these oddities.
2017-02-26
Astronomy picture of the day - 2017 February 26 - A Supercell Thunderstorm Cloud Over Montana
Image Credit & Copyright: Sean R. Heavey
Explanation: Is that a spaceship or a cloud? Although it may seem like an alien mothership, it's actually a impressive thunderstorm cloud called a supercell. Such colossal storm systems center on mesocyclones -- rotating updrafts that can span several kilometers and deliver torrential rain and high winds including tornadoes. Jagged sculptured clouds adorn the supercell's edge, while wind swept dust and rain dominate the center. A tree waits patiently in the foreground. The above supercell cloud was photographed in 2010 July west of Glasgow, Montana, USA, caused minor damage, and lasted several hours before moving on.
2017-02-25
Astronomy picture of the day - 2017 February 25 - All Planets Panorama
Image Credit & Copyright: Tunç Tezel (TWAN)
Explanation: For 360 degrees, a view along the plane of the ecliptic is captured in this remarkable panorama, with seven planets in a starry sky. The mosaic was constructed using images taken during January 24-26, from Nacpan Beach, El Nido in Palawan, Philippines. It covers the eastern horizon (left) in dark early morning hours and the western horizon in evening skies. While the ecliptic runs along the middle traced by a faint band of zodiacal light, the Milky Way also cuts at angles through the frame. Clouds and the Moon join fleeting planet Mercury in the east. Yellowish Saturn, bright star Antares, and Jupiter lie near the ecliptic farther right. Hugging the ecliptic near center are Leo's alpha star Regulus and star cluster M44. The evening planets gathered along the ecliptic above the western horizon, are faint Uranus, ruddy Mars, brilliant Venus, and even fainter Neptune. A well labeled version of the panorama can be viewed by sliding your cursor over the picture, or just following this link.
2017-02-24
Expressões populares portuguesas - Do tempo da Maria Cachucha
Significado:
Muito antigo.
Origem:
A cachucha era uma dança espanhola a três tempos, em que o dançarino, ao som das castanholas,
começava a dança num movimento moderado, que ia acelerando, até terminar num vivo volteio.
Esta dança
teve uma certa voga em França, quando uma célebre dançarina, Fanny Elssler, a dançou na Ópera de Paris.
Em
Portugal, a popular cantiga Maria Cachucha (ao som da qual, no séc. XIX, era usual as pessoas do povo
dançarem) era uma adaptação da cachucha espanhola, com uma letra bastante gracejadora, zombeteira.
Astronomy picture of the day - 2017 February 24 - NGC 3621: Far Beyond the Local Group
Image Credit & Copyright: Processing - Robert Gendler, Roberto Colombari
Data - Hubble Legacy Archive, European Southern Observatory, et al.
Explanation: Far beyond the local group of galaxies lies NGC 3621, some 22 million light-years away. Found in the multi-headed southern constellation Hydra, the winding spiral arms of this gorgeous island universe are loaded with luminous blue star clusters, pinkish starforming regions, and dark dust lanes. Still, for astronomers NGC 3621 has not been just another pretty face-on spiral galaxy. Some of its brighter stars have been used as standard candles to establish important estimates of extragalactic distances and the scale of the Universe. This beautiful image of NGC 3621, is a composite of space- and ground-based telescope data. It traces the loose spiral arms far from the galaxy's brighter central regions for some 100,000 light-years. Spiky foreground stars in our own Milky Way Galaxy and even more distant background galaxies are scattered across the colorful skyscape.
2017-02-23
Astronomy picture of the day - 2017 February 18 - 2017 February 18
Illustration Credit: NASA, JPL-Caltech, Spitzer Space Telescope, Robert Hurt (Spitzer, Caltech)
Explanation: Seven worlds orbit the ultracool dwarf star TRAPPIST-1, a mere 40 light-years away. In May 2016 astronomers using the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) announced the discovery of three planets in the TRAPPIST-1 system. Just announced, additional confirmations and discoveries by the Spitzer Space Telescope and supporting ESO ground-based telescopes have increased the number of known planets to seven. The TRAPPIST-1 planets are likely all rocky and similar in size to Earth, the largest treasure trove of terrestrial planets ever detected around a single star. Because they orbit very close to their faint, tiny star they could also have regions where surface temperatures allow for the presence of liquid water, a key ingredient for life. Their tantalizing proximity to Earth makes them prime candidates for future telescopic explorations of the atmospheres of potentially habitable planets. All seven worlds appear in this artist's illustration, an imagined view from a fictionally powerful telescope near planet Earth. Planet sizes and relative positions are drawn to scale for the Spitzer observations. The system's inner planets are transiting their dim, red, nearly Jupiter-sized parent star.
2017-02-22
Fotografia - Lisboa noctura - Praça dos Restauradores
Estúdio Mário Novais, Praça dos Restauradores, Lisboa, sem data Colecções daFundação Calouste Gulbenkian, Lisboa, Portugal (Flickr Commons)
Astronomy picture of the day - 2017 February 22 - Daphnis and the Rings of Saturn
Image Credit: NASA, JPL-Caltech, Space Science Institute, Cassini
Explanation: What's happening to the rings of Saturn? Nothing much, just a little moon making 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 wide-field version of a previously released image taken last month by the robotic Cassini spacecraft during one of its new Grand Finale orbits. Daphnis can be seen on the far right, sporting ridges likely accumulated from ring particles. Daphnis 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.
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