"Purple rain"
2016-02-22
Astronomy picture of the day - 2016 February 22 - Flying Over Pluto's Moon Charon
Video Credit: NASA, Johns Hopkins U. APL, SwRI, Stuart Robbins
Explanation: Given some poetic license, there is now scientific evidence that hell has frozen over. To start, Greek mythology holds that Charon is the ferryman of the underworld. Next, recent analysis of data taken by the robotic New Horizons spacecraft that shot past Charon -- the namesake that is the largest moon of Pluto -- in July now indicates that the cause of the huge chasm that runs across the 1200-km moon was that a huge internal sea froze. And sincewater expands when it freezes, the already hardened outer crust could not contain it and cracked. To better picture the crack, a fanciful journey over some of Charon's has been digitally created from collected images. The featured video starts by showing the Dark Polar Deposit (dubbed Mordor) near Charon's north pole and then flies over the dwarf-planet-wide canyon. Last, the video shows a much-debated protuberance called Moated Mountain. Understanding the history of Pluto and Charon is helping humanity to better understand both the friendliest and more forbidding places in the early Solar System from which Earth formed and life somehow emerged.
2016-02-21
Astronomy picture of the day - 2016 February 21 - M82: Galaxy with a Supergalactic Wind
Image Credit: NASA, ESA, The Hubble Heritage Team, (STScI/AURA)
Acknowledgement: M. Mountain (STScI), P. Puxley (NSF), J. Gallagher (U. Wisconsin)
Explanation: What's lighting up the Cigar Galaxy? M82, as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas, however. Evidence indicates that this gas is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind. The featured photographic mosaic highlights a specific color of red light strongly emitted by ionized hydrogen gas, showing detailed filaments of this gas. The filaments extend for over 10,000 light years. The 12-million light-year distant Cigar Galaxy is the brightest galaxy in the sky in infrared light, and can be seen in visible light with a small telescope towards the constellation of the Great Bear (Ursa Major).
2016-02-20
Imagens do Mundo - Explosão em Tianjin, China
Vista aérea da destruição causada pela explosão de Tianjin (China) a 15 de agosto de 2015.
Imagens do Mundo - Tempestade - Praia de Bondi, Australia
Tempestade. 6 de novembro, na praia de Bondi na Australia.
Imagens do Mundo - Vulcão Colima, México
Foto - 'El poder de la naturaleza' de Sergio Tapiro del volcán Colima en México.
Imagens do Mundo - Surf na Nazaré, Portugal
Surf numa onda gigante na praia do Norte na Nazaré (Portugal).
Imagens do Mundo - Portugueses à caça de tornados
Ha malucos para tudo. Os cinco amigos e fundadores da Associação de Meteorologia Amadora, Troposfera têm uma atração por tempestades e correm atrás delas, em vez de fugirem delas. No ano passado, juntaram 15 mil euros e gastaram três semanas de férias no centro dos Estados Unidos, à caça de tornados.
Visão - Portugal
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