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2016-02-22

Astronomy picture of the day - 2016 February 22 - Flying Over Pluto's Moon Charon

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Flying Over Pluto's Moon Charon 
Video Credit: NASAJohns Hopkins U. APLSwRI, 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

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M82: Galaxy with a Supergalactic Wind 
Image Credit: NASAESA, 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 - "Refugiados"



"Refugiados"

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

Ennya - "Echoes in rain" - Video - Music

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"Echoes in rain"

Astronomy picture of the day - 2016 February 20 - Where Your Shadow Has Company

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Where Your Shadow Has Company 
Poster Illustration Credit: NASAJPLExoplanet Travel Bureau
Explanation: Want to take a relaxing interstellar vacation? Consider visiting Kepler-16b, a world in a binary star system. In fact Kepler-16b is the first discovered circumbinary planet. It was detected in a wide 229 day orbit around a close pair of cool, low-mass stars some 200 light-years away. The parent stars eclipse one another in their orbits, observed as a dimming of starlight. But Kepler-16b itself was discovered by following the additional very slight dimming produced during its transits. Like sci-fi planet Tatooine of Star Wars fame, two suns would set over its horizon. Still, Kepler 16b is probably not a Tatooine-like terrestrial desert world. Instead, Kepler 16b is thought to be a cold, uninhabitable planet with about the mass of Saturn and a gaseous surface ... so plan to dress accordingly. Or, choose another Visions of the Future vacation destination.