2014-04-20
A imagem do dia 20-04-2014
Image Credit & Copyright: Sigurður Stefnisson
Explanation: Why did a picturesque 2010
volcanic eruption in Iceland create so much ash? Although the large ash plume was not
unparalleled in its abundance, its location was particularly noticeable because it drifted
across such well-populated areas. The Eyjafjallajökull
volcano in southern Iceland began erupting on 2010 March 20, with a second eruption starting under
the center of a small glacier on 2010 April 14. Neither eruption was unusually
powerful. The second eruption, however, melted a large amount of glacial ice which then cooled
and fragmented lava into gritty glass particles that
were carried up with the rising volcanic plume. Pictured
above during the second eruption, lightning
bolts illuminate ash pouring out of the
Eyjafjallajökull volcano.
2014-04-19
A imagem do dia 19-04-2014
Illustration Credit: NASA Ames / SETI Institute / JPL-Caltech, Discovery: Elisa V. Quintana, et al.
Explanation: Planet
Kepler-186f is the first known Earth-size planet to lie within the habitable zone of a star beyond the Sun. Discovered using data
from the prolific planet-hunting Kepler
spacecraft, the distant world orbits its parent star, a cool, dim, M dwarf
star about half the size and mass of the Sun, some 500 light-years away in the
constellation Cygnus. M dwarfs are common,
making up about 70 percent of the stars in our Milky Way galaxy. To be within the habitable zone, where surface temperatures allowing
liquid water are possible, Kepler-186f
orbits close, within 53 million kilometers (about the Mercury-Sun distance)
of the M dwarf star, once every 130 days. Four other planets are known in the
distant system. All four are only a little larger than Earth and in much closer
orbits, also illustrated in the tantalizing artist's vision. While the size and
orbit of Kepler-186f are known, its mass and composition are not, and can't be
determined by Kepler's transit technique. Still,
models suggest that it could be rocky and have an atmosphere, making it potentially the most Earth-like exoplanet discovered so far
...
2014-04-17
Ivete Sangalo e Jorge Ben - "Por causa de você menina" - Video - Musica - Ao vivo
"Por causa de você menina"
2014-04-16
Filme - Documentario - "Portugal 74-75 - Retrato do 25 de Abril"
Documentário de Joaquim Furtado, José Solano de Almeida, Cesário Borga, Isabel Silva Costa – RTP - 119 minutos
2014-04-13
2014-04-12
Angela Merkel nua!
Foto comunicada por Carmen Giri Mira; premonitoria do saque que iria fazer aos Povos muitos anos depois?...
Decididamente, nem quando era jovem agradava ao amigo!
2014-04-11
A imagem do dia 11-04-2014
Video Illustration Credit: Lucie Maquet, Observatoire de Paris, LESIA
Explanation: Asteroids can have rings. In a surprising discovery announced two weeks
ago, the distant asteroid 10199
Chariklo was found to have at least two orbiting rings. Chariklo's diameter
of about 250 kilometers makes it the largest of the measured centaur asteroids,
but now the smallest known object to have rings. The centaur-class minor planet orbits the Sun
between Saturn and Uranus. The above
video gives an artist's illustration of how the rings were discovered.
As Chariklo
passed in 2013 in front of a faint star, unexpected but symmetric dips in the
brightness of the star revealed the rings. Planetary
astronomers are now running computer simulations
designed to investigate how Chariklo's unexpected ring
system might have formed, how it survives, and given the asteroid's low mass
and close passes of other small asteroids and the planet
Uranus, how long it may last.
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