Fórum Defesa Brasil

Enviado: **Qui Nov 27, 2014 9:25 am**

Bem, o outro tópico de fotos da seção é mais focado para aviação, ou então fotos de equipamentos espaciais. Criei esse para ser focado em imagens do espaço, e também eventuais discussões sobre o mesmo.

Começando com uma foto, do mais espetacular planeta do Sistema Solar.

'Tis the Season
December 23, 2013

Winter is approaching in the southern hemisphere of Saturn and with this cold season has come the familiar blue hue that was present in the northern winter hemisphere at the start of NASA's Cassini mission. The changing blue hue that we have learned marks winter at Saturn is likely due to reduction of ultraviolet sunlight and the haze it produces, making the atmosphere clearer and increasing the opportunity for Rayleigh scattering (scattering by molecules and smaller particles) and methane absorption: both processes make the atmosphere blue. The small black dot seen to the right and up from image center, within the ring shadows of the A and F rings, is the shadow of the moon, Prometheus. For an image showing winter in the northern hemisphere see Saturn's Subtle Spectrum.

This view looks toward the unilluminated side of the rings from about 44 degrees below the ring plane. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were taken with the Cassini spacecraft wide-angle camera on July 29, 2013.
This view was acquired at a distance of approximately 1.003 million miles (1.615 million kilometers) from Saturn. Image scale is 58 miles (93 kilometers) per pixel.

Credit: NASA/JPL-Caltech/Space Science Institute

http://saturn.jpl.nasa.gov/photos/image ... ageId=4944

Enviado: **Qui Nov 27, 2014 9:29 am**

Saturn Looms
December 24, 2012

Janus is spotted over Saturn's north pole in this image while Mimas' shadow glides across Saturn.

Janus is the faint dot that appears just above Saturn's north pole. Mimas' shadow can be seen in the southern hemisphere of Saturn, south of the rings' shadow. (Both objects are easier to find in higher resolution versions.)
This view looks toward the unilluminated side of the rings from about 25 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Aug. 24, 2012.

The view was obtained at a distance of approximately 1.6 million miles (2.6 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 80 degrees. Image scale is 94 miles (152 kilometers) per pixel. Janus has been brightened by a factor of 1.3 relative to Saturn to enhance its visibility.

Credit: NASA/JPL-Caltech/Space Science Institute

http://saturn.jpl.nasa.gov/photos/image ... ageId=4707

Enviado: **Qui Nov 27, 2014 9:40 am**

Europa's Stunning Surface
November 21,2014

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution.

The view was previously released as a mosaic with lower resolution and strongly enhanced color (see PIA02590). To create this new version, the images were assembled into a realistic color view of the surface that approximates how Europa would appear to the human eye.

The scene shows the stunning diversity of Europa's surface geology. Long, linear cracks and ridges crisscross the surface, interrupted by regions of disrupted terrain where the surface ice crust has been broken up and re-frozen into new patterns.

Color variations across the surface are associated with differences in geologic feature type and location. For example, areas that appear blue or white contain relatively pure water ice, while reddish and brownish areas include non-ice components in higher concentrations. The polar regions, visible at the left and right of this view, are noticeably bluer than the more equatorial latitudes, which look more white. This color variation is thought to be due to differences in ice grain size in the two locations.

Images taken through near-infrared, green and violet filters have been combined to produce this view. The images have been corrected for light scattered outside of the image, to provide a color correction that is calibrated by wavelength. Gaps in the images have been filled with simulated color based on the color of nearby surface areas with similar terrain types.

This global color view consists of images acquired by the Galileo Solid-State Imaging (SSI) experiment on the spacecraft's first and fourteenth orbits through the Jupiter system, in 1995 and 1998, respectively. Image scale is 1 mile (1.6 kilometers) per pixel. North on Europa is at right.

http://www.jpl.nasa.gov/spaceimages/det ... d=PIA19048

Enviado: **Dom Nov 30, 2014 1:22 pm**

New Year's Io
December 16, 2004

Io Above Clouds on New Year's Day, 2001
January 23, 2001
The moon Io floats above the cloudtops of Jupiter in this image captured by NASA's Cassini spacecraft on the dawn of the new millennium, Jan. 1, 2001, two days after Cassini's closest approach to Jupiter. The image is deceiving: There is room for two and a half Jupiters between Io and Jupiter's clouds. Io is the size of our Moon.
Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.
Credit: NASA/JPL/University of Arizona

http://saturn.jpl.nasa.gov/photos/image ... mageId=654

Enviado: **Qua Dez 03, 2014 12:24 pm**

ALMA Milky Way

Image Credit & Copyright: Yuri Beletsky (Las Campanas Observatory, Carnegie Institution)

Explanation: This alluring all-skyscape was taken 5,100 meters above sea level, from the Chajnantor Plateau in the Chilean Andes. Viewed through the site's rarefied atmosphere at about 50% sea level pressure, the gorgeous Milky Way stretches through the scene. Its cosmic rifts of dust, stars, and nebulae are joined by Venus, a brilliant morning star immersed in a strong band of predawn Zodiacal light. Still not completely dark even at this high altitude, the night sky's greenish cast is due to airglow emission from oxygen atoms. Around the horizon the dish antenna units of the Atacama Large Millimeter/submillimeter Array, ALMA, explore the universe at wavelengths over 1,000 times longer than visible light.

http://apod.nasa.gov/apod/ap140724.html

Enviado: **Qua Dez 03, 2014 12:30 pm**

M74: The Perfect Spiral

Image Credit: NASA, ESA, and the Hubble Heritage (STScI / AURA)- ESA / Hubble Collaboration
Acknowledgment: R. Chandar (Univ. Toledo) and J. Miller (Univ. Michigan)

Explanation: If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view. Classified as an Sc galaxy, the grand design of M74's graceful spiral arms are traced by bright blue star clusters and dark cosmic dust lanes. Constructed from image data recorded in 2003 and 2005, this sharp composite is from the Hubble Space Telescope's Advanced Camera for Surveys. Spanning about 30,000 light-years across the face of M74, it includes exposures recording emission from hydrogen atoms, highlighting the reddish glow of the galaxy's large star-forming regions. Recently, many astronomers are tracking a bright supernova that has been seen in M74.

http://apod.nasa.gov/apod/ap130811.html

Enviado: **Qui Jan 01, 2015 5:45 pm**

This set of three images shows views three seconds apart as the larger of Mars' two moons, Phobos, passed directly in front of the sun as seen by NASA's Mars rover Curiosity.
This set of three images shows views three seconds apart as the larger of Mars' two moons, Phobos, passed directly in front of the sun as seen by NASA's Mars rover Curiosity. Curiosity photographed this annular, or ring, eclipse with the telephoto-lens camera of the rover's Mast Camera pair (right Mastcam) on Aug. 20, 2013, the 369th Martian day, or sol, of Curiosity's work on Mars.

Curiosity paused during its drive that sol for a set of observations that the camera team carefully calculated to record this celestial event. The rover's observations of Phobos help researchers to make measurements of the moon's orbit even more precise. Because this eclipse occurred near mid-day at Curiosity's location on Mars, Phobos was nearly overhead, closer to the rover than it would have been earlier in the morning or later in the afternoon. This timing made Phobos' silhouette larger against the sun -- as close to a total eclipse of the sun as is possible from Mars.

Malin Space Science Systems, San Diego, built and operates Mastcam. NASA's Jet Propulsion Laboratory manages the Mars Science Laboratory mission and the mission's Curiosity rover for NASA's Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL, a division of the California Institute of Technology in Pasadena.

http://www.jpl.nasa.gov/spaceimages/det ... d=PIA17356

Enviado: **Sáb Jan 17, 2015 10:22 am**

Enviado: **Qua Jan 28, 2015 11:08 pm**

Astrônomos encontram planeta com anéis maiores que Saturno
Após analisar dados colhidos por observatório que lê eclipses em outros sistemas, cientistas acreditam ter descoberto gigante gasoso com sistema de anéis.
Paul Rincon
Editor de Ciência da BBC News

Imagem

Representação artística do que pode ser a aparência do sistema de anéis descoberto (Foto: Ron Miller/BBC)

Astrônomos holandeses e americanos afirmam ter descoberto um planeta com um sistema de anéis gigantesco, 200 vezes maior do que os anéis de Saturno.

Segundo os pesquisadores, esta é a primeira estrutura deste tipo detectada em volta de um planeta fora do Sistema Solar.
Os cientistas afirmam que o sistema provavelmente tem mais de 30 anéis, cada um medindo dezenas de milhões de quilômetros de diâmetro.

Espaços detectados no sistema de anéis também sugerem que parte do material em volta do planeta pode estar se unindo para formar luas - um fenômeno que pode ser observado nos anéis de Saturno.

"Você pode pensar nisto (neste sistema) como um tipo de super-Saturno", disse o professor Eric Mamajek, da Universidade de Rochester, nos Estados Unidos.

Exoplanetas

Imagem

Esta imagem mostra como o sistema seria visível na Terra caso estivesse no lugar de Saturno (Foto: N. Kenworthy/Leiden/BBC)

Os anéis foram encontrados graças a dados levantados pelo observatório SuperWASP, que pode detectar exoplanetas quando estes cruzam em frente às estrelas em volta das quais orbitam - provocando um enfraquecimento da luz emanada por estas.

Neste caso, os astrônomos observaram uma série complexa de eclipses profundos que durou 56 dias. Eles acreditam que este fenômeno foi causado por um planeta com um sistema de anéis gigante que bloqueou a luz enquanto passava em frente da estrela J1407.

"A curvatura da luz, de ponta a ponta, levou cerca de dois meses, mas podíamos ver mudanças rápidas no espaço de uma noite", disse à BBC o líder da pesquisa Matthew Kenworthy, da Universidade de Leiden, na Holanda.

"Durante o período entre meia e uma hora, a (luz da) estrela podia diminuir entre 30 ou 40%", acrescentou.

Se os anéis de Saturno fossem do mesmo tamanho dos observados neste planeta, eles seriam visíveis da Terra durante a noite e muito maiores do que a Lua cheia.

No ano passado os astrônomos tentaram encontrar o planeta, olhar diretamente para o corpo celeste e não apenas para os eclipses, mas não conseguiram.

Mesmo assim, Kenworthy acredita que a única coisa que poderia manter estes anéis unidos "é um planeta".
A equipe de pesquisadores acredita que o planeta provavelmente é um gigante de gás, como Júpiter, mas entre dez e 40 vezes maior.

Amadores

O planeta distante, batizado de J1407b, também poderá dar pistas sobre o processo que levou à formação de luas em volta de gigantes gasosos em nosso Sistema Solar.

"A comunidade de ciência planetária cria teorias há décadas, (especulando) se Júpiter e Saturno teriam, em um estágio inicial, discos em volta deles que levaram à formação de satélites, disse Eric Mamajek.

Os astrônomos encontraram pelo menos uma falha na estrutura dos anéis.

"Uma explicação óbvia (para esta falha) é que um satélite se formou e abriu esta falha. A massa do satélite poderia ser algo entre a Terra e Marte", disse Kenworthy.

Os pesquisadores estão incentivando astronônomos amadores a co-monitorar o sistema da estrela J1407, para ajudar a detectar o próximo eclipse dos anéis.

As observações da J1407 podem ser relatadas à Associação Americana de Observadores de Variações de Estrelas (AAVSO, na sigla em inglês).

http://g1.globo.com/ciencia-e-saude/not ... turno.html